fix(pos): enrich quotation/layaway items from inventory and allow final payment on layaway complete

Quotation and layaway endpoints were calling calculate_totals() on raw
input items without looking up unit_price/tax_rate from inventory, causing
KeyError. Added _enrich_items() helper (with customer price tier support).
Also removed non-existent discount_total column from quotations INSERT,
and made layaway complete accept a final payment for the remaining balance.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pos/app.py

@@ -16,6 +16,15 @@ def create_app():
     from blueprints.catalog_bp import catalog_bp
     app.register_blueprint(catalog_bp)
 
+    from blueprints.pos_bp import pos_bp
+    app.register_blueprint(pos_bp)
+
+    from blueprints.customers_bp import customers_bp
+    app.register_blueprint(customers_bp)
+
+    from blueprints.cashregister_bp import cashregister_bp
+    app.register_blueprint(cashregister_bp)
+
     # Health check
     @app.route('/pos/health')
     def health():
@@ -35,6 +44,14 @@ def create_app():
     def pos_inventory():
         return render_template('inventory.html')
 
+    @app.route('/pos/sale')
+    def pos_sale():
+        return render_template('pos.html')
+
+    @app.route('/pos/customers')
+    def pos_customers():
+        return render_template('customers.html')
+
     @app.route('/pos/static/<path:filename>')
     def pos_static(filename):
         return send_from_directory('static', filename)

pos/blueprints/cashregister_bp.py

@@ -0,0 +1,563 @@
+# /home/Autopartes/pos/blueprints/cashregister_bp.py
+"""Cash register blueprint: open/close register, cash movements, X/Z cuts."""
+
+from datetime import datetime
+from flask import Blueprint, request, jsonify, g
+from middleware import require_auth
+from tenant_db import get_tenant_conn
+from services.audit import log_action
+
+cashregister_bp = Blueprint('cashregister', __name__, url_prefix='/pos/api/register')
+
+
+@cashregister_bp.route('/open', methods=['POST'])
+@require_auth('pos.sell')
+def open_register():
+    """Open a cash register session.
+
+    Body: {register_number: int, opening_amount: float}
+
+    Business rules:
+    - An employee can only have one open register at a time
+    - Register number identifies the physical register (1, 2, 3...)
+    """
+    data = request.get_json() or {}
+    register_number = data.get('register_number')
+    opening_amount = float(data.get('opening_amount', 0))
+
+    if not register_number:
+        return jsonify({'error': 'register_number required'}), 400
+    if opening_amount < 0:
+        return jsonify({'error': 'opening_amount cannot be negative'}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    # Check if employee already has an open register
+    cur.execute("""
+        SELECT id, register_number FROM cash_registers
+        WHERE employee_id = %s AND status = 'open'
+    """, (g.employee_id,))
+    existing = cur.fetchone()
+    if existing:
+        cur.close(); conn.close()
+        return jsonify({
+            'error': f'You already have register #{existing[1]} open (id={existing[0]}). Close it first.'
+        }), 409
+
+    # Check if this register number is already open at this branch
+    cur.execute("""
+        SELECT id, employee_id FROM cash_registers
+        WHERE branch_id = %s AND register_number = %s AND status = 'open'
+    """, (g.branch_id, register_number))
+    in_use = cur.fetchone()
+    if in_use:
+        cur.close(); conn.close()
+        return jsonify({'error': f'Register #{register_number} is already open by another employee'}), 409
+
+    try:
+        cur.execute("""
+            INSERT INTO cash_registers
+                (branch_id, employee_id, register_number, opening_amount, status)
+            VALUES (%s,%s,%s,%s,'open')
+            RETURNING id, opened_at
+        """, (g.branch_id, g.employee_id, register_number, opening_amount))
+        reg_id, opened_at = cur.fetchone()
+
+        log_action(conn, 'REGISTER_OPEN', 'cash_register', reg_id,
+                   new_value={'register_number': register_number, 'opening_amount': opening_amount})
+
+        conn.commit()
+        cur.close(); conn.close()
+        return jsonify({
+            'id': reg_id,
+            'register_number': register_number,
+            'opening_amount': opening_amount,
+            'opened_at': str(opened_at),
+            'message': f'Register #{register_number} opened'
+        }), 201
+
+    except Exception as e:
+        conn.rollback()
+        cur.close(); conn.close()
+        return jsonify({'error': str(e)}), 500
+
+
+@cashregister_bp.route('/current', methods=['GET'])
+@require_auth('pos.sell')
+def current_register():
+    """Get the current open register for this employee."""
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("""
+        SELECT cr.id, cr.register_number, cr.opening_amount, cr.opened_at,
+               cr.branch_id, b.name as branch_name
+        FROM cash_registers cr
+        LEFT JOIN branches b ON cr.branch_id = b.id
+        WHERE cr.employee_id = %s AND cr.status = 'open'
+    """, (g.employee_id,))
+    row = cur.fetchone()
+
+    if not row:
+        cur.close(); conn.close()
+        return jsonify({'register': None, 'message': 'No open register'})
+
+    register = {
+        'id': row[0], 'register_number': row[1],
+        'opening_amount': float(row[2]) if row[2] else 0,
+        'opened_at': str(row[3]),
+        'branch_id': row[4], 'branch_name': row[5],
+    }
+
+    cur.close(); conn.close()
+    return jsonify({'register': register})
+
+
+@cashregister_bp.route('/movement', methods=['POST'])
+@require_auth('pos.sell')
+def cash_movement():
+    """Record a cash in/out movement with mandatory reason.
+
+    Body: {type: 'in'|'out', amount: float, reason: str}
+    """
+    data = request.get_json() or {}
+    mov_type = data.get('type')
+    amount = float(data.get('amount', 0))
+    reason = data.get('reason', '').strip()
+
+    if mov_type not in ('in', 'out'):
+        return jsonify({'error': "type must be 'in' or 'out'"}), 400
+    if amount <= 0:
+        return jsonify({'error': 'amount must be positive'}), 400
+    if not reason or len(reason) < 3:
+        return jsonify({'error': 'reason required (min 3 characters)'}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    # Get employee's open register
+    cur.execute("""
+        SELECT id FROM cash_registers
+        WHERE employee_id = %s AND status = 'open'
+    """, (g.employee_id,))
+    reg = cur.fetchone()
+    if not reg:
+        cur.close(); conn.close()
+        return jsonify({'error': 'No open register. Open a register first.'}), 400
+
+    register_id = reg[0]
+
+    try:
+        cur.execute("""
+            INSERT INTO cash_movements (register_id, type, amount, reason, employee_id)
+            VALUES (%s,%s,%s,%s,%s)
+            RETURNING id, created_at
+        """, (register_id, mov_type, amount, reason, g.employee_id))
+        mov_id, created_at = cur.fetchone()
+
+        log_action(conn, f'CASH_{mov_type.upper()}', 'cash_register', register_id,
+                   new_value={'movement_id': mov_id, 'type': mov_type,
+                              'amount': amount, 'reason': reason})
+
+        conn.commit()
+        cur.close(); conn.close()
+        return jsonify({
+            'id': mov_id,
+            'type': mov_type,
+            'amount': amount,
+            'reason': reason,
+            'created_at': str(created_at),
+            'message': 'Movement recorded'
+        }), 201
+
+    except Exception as e:
+        conn.rollback()
+        cur.close(); conn.close()
+        return jsonify({'error': str(e)}), 500
+
+
+def _compute_register_summary(conn, register_id):
+    """Compute the register summary for X-cut or Z-cut.
+
+    Returns a dict with totals by payment method, cash movements, and expected cash amount.
+    """
+    cur = conn.cursor()
+
+    # Get register info
+    cur.execute("""
+        SELECT opening_amount, opened_at, employee_id
+        FROM cash_registers WHERE id = %s
+    """, (register_id,))
+    reg = cur.fetchone()
+    opening_amount = float(reg[0]) if reg[0] else 0
+
+    # Sales totals by payment method
+    cur.execute("""
+        SELECT payment_method, COUNT(*), COALESCE(SUM(total), 0)
+        FROM sales
+        WHERE register_id = %s AND status = 'completed'
+        GROUP BY payment_method
+    """, (register_id,))
+    sales_by_method = {}
+    total_sales = 0.0
+    total_sales_count = 0
+    for r in cur.fetchall():
+        method, count, amount = r[0], r[1], float(r[2])
+        sales_by_method[method] = {'count': count, 'amount': amount}
+        total_sales += amount
+        total_sales_count += count
+
+    # Cash sales specifically (for expected cash calculation)
+    cash_from_sales = sales_by_method.get('efectivo', {}).get('amount', 0)
+
+    # Change given (cash out)
+    cur.execute("""
+        SELECT COALESCE(SUM(change_given), 0) FROM sales
+        WHERE register_id = %s AND status = 'completed' AND payment_method = 'efectivo'
+    """, (register_id,))
+    change_given = float(cur.fetchone()[0])
+
+    # Cash movements
+    cur.execute("""
+        SELECT type, COALESCE(SUM(amount), 0) FROM cash_movements
+        WHERE register_id = %s GROUP BY type
+    """, (register_id,))
+    movements = {'in': 0.0, 'out': 0.0}
+    for r in cur.fetchall():
+        movements[r[0]] = float(r[1])
+
+    # Cancelled sales
+    cur.execute("""
+        SELECT COUNT(*), COALESCE(SUM(total), 0) FROM sales
+        WHERE register_id = %s AND status = 'cancelled'
+    """, (register_id,))
+    cancelled = cur.fetchone()
+    cancelled_count = cancelled[0]
+    cancelled_amount = float(cancelled[1])
+
+    # Expected cash = opening + cash sales - change + cash_in - cash_out
+    expected_cash = round(
+        opening_amount + cash_from_sales - change_given + movements['in'] - movements['out'],
+        2
+    )
+
+    # Detail of cash movements
+    cur.execute("""
+        SELECT id, type, amount, reason, created_at
+        FROM cash_movements WHERE register_id = %s ORDER BY created_at
+    """, (register_id,))
+    movement_detail = []
+    for r in cur.fetchall():
+        movement_detail.append({
+            'id': r[0], 'type': r[1], 'amount': float(r[2]),
+            'reason': r[3], 'created_at': str(r[4])
+        })
+
+    cur.close()
+
+    return {
+        'opening_amount': opening_amount,
+        'sales_by_method': sales_by_method,
+        'total_sales': round(total_sales, 2),
+        'total_sales_count': total_sales_count,
+        'cash_from_sales': round(cash_from_sales, 2),
+        'change_given': round(change_given, 2),
+        'cash_movements_in': round(movements['in'], 2),
+        'cash_movements_out': round(movements['out'], 2),
+        'movement_detail': movement_detail,
+        'cancelled_count': cancelled_count,
+        'cancelled_amount': round(cancelled_amount, 2),
+        'expected_cash': expected_cash,
+    }
+
+
+@cashregister_bp.route('/cut-x', methods=['GET'])
+@require_auth('pos.sell')
+def cut_x():
+    """Partial cut (corte X): read-only summary without closing the register."""
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("""
+        SELECT id FROM cash_registers
+        WHERE employee_id = %s AND status = 'open'
+    """, (g.employee_id,))
+    reg = cur.fetchone()
+    if not reg:
+        cur.close(); conn.close()
+        return jsonify({'error': 'No open register'}), 400
+
+    register_id = reg[0]
+    summary = _compute_register_summary(conn, register_id)
+
+    cur.close(); conn.close()
+    return jsonify({
+        'type': 'X',
+        'register_id': register_id,
+        'status': 'open',
+        **summary,
+    })
+
+
+@cashregister_bp.route('/cut-z', methods=['POST'])
+@require_auth('pos.sell')
+def cut_z():
+    """Final cut (corte Z): close the register.
+
+    Body: {closing_amount: float}  (the amount physically counted in the register)
+    """
+    data = request.get_json() or {}
+    closing_amount = float(data.get('closing_amount', 0))
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("""
+        SELECT id FROM cash_registers
+        WHERE employee_id = %s AND status = 'open'
+    """, (g.employee_id,))
+    reg = cur.fetchone()
+    if not reg:
+        cur.close(); conn.close()
+        return jsonify({'error': 'No open register'}), 400
+
+    register_id = reg[0]
+    summary = _compute_register_summary(conn, register_id)
+
+    expected = summary['expected_cash']
+    difference = round(closing_amount - expected, 2)
+
+    try:
+        cur.execute("""
+            UPDATE cash_registers
+            SET closing_amount = %s, expected_amount = %s, difference = %s,
+                status = 'closed', closed_at = NOW()
+            WHERE id = %s
+        """, (closing_amount, expected, difference, register_id))
+
+        log_action(conn, 'REGISTER_CLOSE', 'cash_register', register_id,
+                   new_value={
+                       'closing_amount': closing_amount,
+                       'expected_amount': expected,
+                       'difference': difference,
+                       'total_sales': summary['total_sales'],
+                   })
+
+        conn.commit()
+        cur.close(); conn.close()
+
+        return jsonify({
+            'type': 'Z',
+            'register_id': register_id,
+            'status': 'closed',
+            'closing_amount': closing_amount,
+            'expected_amount': expected,
+            'difference': difference,
+            **summary,
+        })
+
+    except Exception as e:
+        conn.rollback()
+        cur.close(); conn.close()
+        return jsonify({'error': str(e)}), 500
+
+
+@cashregister_bp.route('/history', methods=['GET'])
+@require_auth('pos.view')
+def register_history():
+    """List closed registers with summary.
+
+    Query params: date_from, date_to, employee_id, page, per_page
+    """
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    page = int(request.args.get('page', 1))
+    per_page = min(int(request.args.get('per_page', 50)), 200)
+
+    where_clauses = ["cr.status = 'closed'"]
+    params = []
+
+    if g.branch_id:
+        where_clauses.append("cr.branch_id = %s")
+        params.append(g.branch_id)
+
+    date_from = request.args.get('date_from')
+    date_to = request.args.get('date_to')
+    employee_id = request.args.get('employee_id')
+
+    if date_from:
+        where_clauses.append("cr.closed_at >= %s")
+        params.append(date_from)
+    if date_to:
+        where_clauses.append("cr.closed_at < %s::date + interval '1 day'")
+        params.append(date_to)
+    if employee_id:
+        where_clauses.append("cr.employee_id = %s")
+        params.append(int(employee_id))
+
+    where = " AND ".join(where_clauses)
+
+    cur.execute(f"SELECT count(*) FROM cash_registers cr WHERE {where}", params)
+    total = cur.fetchone()[0]
+
+    cur.execute(f"""
+        SELECT cr.id, cr.register_number, cr.opening_amount, cr.closing_amount,
+               cr.expected_amount, cr.difference, cr.opened_at, cr.closed_at,
+               cr.employee_id, e.name as employee_name
+        FROM cash_registers cr
+        LEFT JOIN employees e ON cr.employee_id = e.id
+        WHERE {where}
+        ORDER BY cr.closed_at DESC
+        LIMIT %s OFFSET %s
+    """, params + [per_page, (page - 1) * per_page])
+
+    registers = []
+    for r in cur.fetchall():
+        registers.append({
+            'id': r[0], 'register_number': r[1],
+            'opening_amount': float(r[2]) if r[2] else 0,
+            'closing_amount': float(r[3]) if r[3] else 0,
+            'expected_amount': float(r[4]) if r[4] else 0,
+            'difference': float(r[5]) if r[5] else 0,
+            'opened_at': str(r[6]), 'closed_at': str(r[7]),
+            'employee_id': r[8], 'employee_name': r[9],
+        })
+
+    cur.close(); conn.close()
+
+    total_pages = (total + per_page - 1) // per_page
+    return jsonify({
+        'data': registers,
+        'pagination': {'page': page, 'per_page': per_page, 'total': total, 'total_pages': total_pages}
+    })
+
+
+@cashregister_bp.route('/daily-summary', methods=['GET'])
+@require_auth('pos.view')
+def daily_summary():
+    """Consolidated daily summary across all registers for a given date.
+
+    Query params:
+        date: YYYY-MM-DD (default: today)
+
+    Returns aggregated totals: total sales, total by payment method,
+    total movements, and per-register breakdown.
+    """
+    from datetime import date as date_type
+    target_date = request.args.get('date', date_type.today().isoformat())
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    branch_clause = ""
+    params = [target_date, target_date]
+    if g.branch_id:
+        branch_clause = "AND s.branch_id = %s"
+        params.append(g.branch_id)
+
+    # Total sales by payment method for the date
+    cur.execute(f"""
+        SELECT s.payment_method, COUNT(*), COALESCE(SUM(s.total), 0)
+        FROM sales s
+        WHERE s.created_at >= %s::date
+          AND s.created_at < %s::date + interval '1 day'
+          AND s.status = 'completed'
+          {branch_clause}
+        GROUP BY s.payment_method
+    """, params)
+
+    sales_by_method = {}
+    total_sales = 0.0
+    total_sales_count = 0
+    for method, count, amount in cur.fetchall():
+        sales_by_method[method] = {'count': count, 'amount': float(amount)}
+        total_sales += float(amount)
+        total_sales_count += count
+
+    # Cancelled sales
+    cancel_params = [target_date, target_date]
+    if g.branch_id:
+        cancel_params.append(g.branch_id)
+    cur.execute(f"""
+        SELECT COUNT(*), COALESCE(SUM(s.total), 0)
+        FROM sales s
+        WHERE s.created_at >= %s::date
+          AND s.created_at < %s::date + interval '1 day'
+          AND s.status = 'cancelled'
+          {branch_clause}
+    """, cancel_params)
+    cancelled = cur.fetchone()
+    cancelled_count = cancelled[0]
+    cancelled_amount = float(cancelled[1])
+
+    # Cash movements for the date
+    mov_params = [target_date, target_date]
+    mov_branch_clause = ""
+    if g.branch_id:
+        mov_branch_clause = "AND cr.branch_id = %s"
+        mov_params.append(g.branch_id)
+
+    cur.execute(f"""
+        SELECT cm.type, COUNT(*), COALESCE(SUM(cm.amount), 0)
+        FROM cash_movements cm
+        JOIN cash_registers cr ON cm.register_id = cr.id
+        WHERE cm.created_at >= %s::date
+          AND cm.created_at < %s::date + interval '1 day'
+          {mov_branch_clause}
+        GROUP BY cm.type
+    """, mov_params)
+    movements = {'in': {'count': 0, 'amount': 0.0}, 'out': {'count': 0, 'amount': 0.0}}
+    for mov_type, count, amount in cur.fetchall():
+        movements[mov_type] = {'count': count, 'amount': float(amount)}
+
+    # Per-register breakdown
+    reg_params = [target_date, target_date]
+    reg_branch_clause = ""
+    if g.branch_id:
+        reg_branch_clause = "AND cr.branch_id = %s"
+        reg_params.append(g.branch_id)
+
+    cur.execute(f"""
+        SELECT cr.id, cr.register_number, cr.status,
+               cr.opening_amount, cr.closing_amount, cr.expected_amount,
+               cr.difference, cr.opened_at, cr.closed_at,
+               e.name as employee_name,
+               (SELECT COUNT(*) FROM sales s WHERE s.register_id = cr.id AND s.status = 'completed') as sale_count,
+               (SELECT COALESCE(SUM(s.total), 0) FROM sales s WHERE s.register_id = cr.id AND s.status = 'completed') as sale_total
+        FROM cash_registers cr
+        LEFT JOIN employees e ON cr.employee_id = e.id
+        WHERE cr.opened_at >= %s::date
+          AND cr.opened_at < %s::date + interval '1 day'
+          {reg_branch_clause}
+        ORDER BY cr.opened_at
+    """, reg_params)
+
+    registers = []
+    for r in cur.fetchall():
+        registers.append({
+            'id': r[0], 'register_number': r[1], 'status': r[2],
+            'opening_amount': float(r[3]) if r[3] else 0,
+            'closing_amount': float(r[4]) if r[4] else 0,
+            'expected_amount': float(r[5]) if r[5] else 0,
+            'difference': float(r[6]) if r[6] else 0,
+            'opened_at': str(r[7]) if r[7] else None,
+            'closed_at': str(r[8]) if r[8] else None,
+            'employee_name': r[9],
+            'sale_count': r[10], 'sale_total': float(r[11]),
+        })
+
+    cur.close(); conn.close()
+
+    return jsonify({
+        'date': target_date,
+        'total_sales': round(total_sales, 2),
+        'total_sales_count': total_sales_count,
+        'sales_by_method': sales_by_method,
+        'cancelled_count': cancelled_count,
+        'cancelled_amount': round(cancelled_amount, 2),
+        'movements_in': movements['in'],
+        'movements_out': movements['out'],
+        'registers': registers,
+    })

pos/blueprints/customers_bp.py

@@ -0,0 +1,465 @@
+# /home/Autopartes/pos/blueprints/customers_bp.py
+"""Customers blueprint: CRUD, credit management, vehicles, account statements."""
+
+import json
+from flask import Blueprint, request, jsonify, g
+from middleware import require_auth, has_permission
+from tenant_db import get_tenant_conn
+from services.audit import log_action
+
+customers_bp = Blueprint('customers', __name__, url_prefix='/pos/api/customers')
+
+
+# ─── Customer CRUD ─────────────────────────────
+
+@customers_bp.route('', methods=['GET'])
+@require_auth('customers.view')
+def list_customers():
+    """Search/list customers. Supports autocomplete-style search by name, RFC, phone.
+
+    Query params:
+        q: search string (matches name, RFC, phone via ILIKE)
+        page: page number (default 1)
+        per_page: items per page (default 50, max 200)
+        branch_id: filter by branch (default: current user's branch)
+    """
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    page = int(request.args.get('page', 1))
+    per_page = min(int(request.args.get('per_page', 50)), 200)
+    search = request.args.get('q', '').strip()
+    branch_id = request.args.get('branch_id')
+
+    where_clauses = ["c.is_active = true"]
+    params = []
+
+    if branch_id:
+        where_clauses.append("c.branch_id = %s")
+        params.append(int(branch_id))
+    if search:
+        where_clauses.append(
+            "(c.name ILIKE %s OR c.rfc ILIKE %s OR c.phone ILIKE %s OR c.razon_social ILIKE %s)"
+        )
+        params.extend([f'%{search}%'] * 4)
+
+    where = " AND ".join(where_clauses)
+
+    # Count
+    cur.execute(f"SELECT count(*) FROM customers c WHERE {where}", params)
+    total = cur.fetchone()[0]
+
+    # Fetch
+    cur.execute(f"""
+        SELECT c.id, c.name, c.rfc, c.razon_social, c.phone, c.email,
+               c.price_tier, c.credit_limit, c.credit_balance, c.vehicle_info,
+               c.branch_id
+        FROM customers c
+        WHERE {where}
+        ORDER BY c.name
+        LIMIT %s OFFSET %s
+    """, params + [per_page, (page - 1) * per_page])
+
+    customers = []
+    for r in cur.fetchall():
+        customers.append({
+            'id': r[0], 'name': r[1], 'rfc': r[2], 'razon_social': r[3],
+            'phone': r[4], 'email': r[5], 'price_tier': r[6],
+            'credit_limit': float(r[7]) if r[7] else 0,
+            'credit_balance': float(r[8]) if r[8] else 0,
+            'vehicle_info': r[9],
+            'branch_id': r[10],
+        })
+
+    cur.close()
+    conn.close()
+
+    total_pages = (total + per_page - 1) // per_page
+    return jsonify({
+        'data': customers,
+        'pagination': {'page': page, 'per_page': per_page, 'total': total, 'total_pages': total_pages}
+    })
+
+
+@customers_bp.route('/<int:customer_id>', methods=['GET'])
+@require_auth('customers.view')
+def get_customer(customer_id):
+    """Get customer details with credit info, vehicle history, and recent purchases."""
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("""
+        SELECT id, branch_id, name, rfc, razon_social, regimen_fiscal, uso_cfdi,
+               cp, email, phone, address, price_tier, credit_limit, credit_balance,
+               is_active, vehicle_info, created_at
+        FROM customers WHERE id = %s
+    """, (customer_id,))
+    row = cur.fetchone()
+    if not row:
+        cur.close(); conn.close()
+        return jsonify({'error': 'Customer not found'}), 404
+
+    cols = [desc[0] for desc in cur.description]
+    customer = dict(zip(cols, row))
+
+    # Convert Decimal to float
+    for k in ('credit_limit', 'credit_balance'):
+        if customer.get(k) is not None:
+            customer[k] = float(customer[k])
+
+    customer['created_at'] = str(customer['created_at']) if customer['created_at'] else None
+
+    # Recent purchases (last 20)
+    cur.execute("""
+        SELECT s.id, s.total, s.payment_method, s.sale_type, s.status, s.created_at,
+               e.name as employee_name
+        FROM sales s
+        LEFT JOIN employees e ON s.employee_id = e.id
+        WHERE s.customer_id = %s AND s.status != 'cancelled'
+        ORDER BY s.created_at DESC
+        LIMIT 20
+    """, (customer_id,))
+    customer['recent_purchases'] = []
+    for r in cur.fetchall():
+        customer['recent_purchases'].append({
+            'id': r[0], 'total': float(r[1]) if r[1] else 0,
+            'payment_method': r[2], 'sale_type': r[3],
+            'status': r[4], 'created_at': str(r[5]),
+            'employee_name': r[6],
+        })
+
+    # Credit summary
+    customer['credit_available'] = round(
+        float(customer['credit_limit']) - float(customer['credit_balance']), 2
+    )
+
+    cur.close()
+    conn.close()
+    return jsonify(customer)
+
+
+@customers_bp.route('', methods=['POST'])
+@require_auth('customers.create')
+def create_customer():
+    """Create a new customer.
+
+    Body: {name, rfc, razon_social, regimen_fiscal, uso_cfdi, cp, email,
+           phone, address, price_tier, credit_limit, vehicle_info}
+    """
+    data = request.get_json() or {}
+    if not data.get('name'):
+        return jsonify({'error': 'name is required'}), 400
+
+    branch_id = data.get('branch_id', g.branch_id)
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    try:
+        cur.execute("""
+            INSERT INTO customers
+                (branch_id, name, rfc, razon_social, regimen_fiscal, uso_cfdi,
+                 cp, email, phone, address, price_tier, credit_limit, vehicle_info)
+            VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)
+            RETURNING id
+        """, (
+            branch_id, data['name'], data.get('rfc'), data.get('razon_social'),
+            data.get('regimen_fiscal'), data.get('uso_cfdi', 'G03'),
+            data.get('cp'), data.get('email'), data.get('phone'),
+            data.get('address'), data.get('price_tier', 1),
+            data.get('credit_limit', 0),
+            json.dumps(data['vehicle_info']) if data.get('vehicle_info') else None
+        ))
+        customer_id = cur.fetchone()[0]
+
+        log_action(conn, 'CUSTOMER_CREATE', 'customer', customer_id,
+                   new_value={'name': data['name'], 'rfc': data.get('rfc')})
+
+        conn.commit()
+        cur.close(); conn.close()
+        return jsonify({'id': customer_id, 'message': 'Customer created'}), 201
+
+    except Exception as e:
+        conn.rollback()
+        cur.close(); conn.close()
+        return jsonify({'error': str(e)}), 500
+
+
+@customers_bp.route('/<int:customer_id>', methods=['PUT'])
+@require_auth('customers.edit')
+def update_customer(customer_id):
+    """Update customer fields. Credit limit changes require customers.edit_credit permission."""
+    data = request.get_json() or {}
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    # Verify customer exists
+    cur.execute("SELECT id, credit_limit FROM customers WHERE id = %s", (customer_id,))
+    existing = cur.fetchone()
+    if not existing:
+        cur.close(); conn.close()
+        return jsonify({'error': 'Customer not found'}), 404
+
+    # Credit limit change requires special permission
+    if 'credit_limit' in data and float(data['credit_limit']) != float(existing[1] or 0):
+        if not has_permission('customers.edit_credit'):
+            cur.close(); conn.close()
+            return jsonify({'error': 'Permission customers.edit_credit required to change credit limit'}), 403
+
+        log_action(conn, 'CREDIT_CHANGE', 'customer', customer_id,
+                   old_value={'credit_limit': float(existing[1] or 0)},
+                   new_value={'credit_limit': float(data['credit_limit'])})
+
+    # Build dynamic update
+    allowed = ['name', 'rfc', 'razon_social', 'regimen_fiscal', 'uso_cfdi',
+               'cp', 'email', 'phone', 'address', 'price_tier', 'credit_limit',
+               'vehicle_info', 'is_active', 'branch_id']
+    sets = []
+    vals = []
+    for field in allowed:
+        if field in data:
+            val = data[field]
+            if field == 'vehicle_info' and isinstance(val, (dict, list)):
+                val = json.dumps(val)
+            sets.append(f"{field} = %s")
+            vals.append(val)
+
+    if not sets:
+        cur.close(); conn.close()
+        return jsonify({'error': 'No fields to update'}), 400
+
+    vals.append(customer_id)
+    cur.execute(f"UPDATE customers SET {', '.join(sets)} WHERE id = %s", vals)
+
+    conn.commit()
+    cur.close(); conn.close()
+    return jsonify({'message': 'Customer updated'})
+
+
+@customers_bp.route('/<int:customer_id>/statement', methods=['GET'])
+@require_auth('customers.view')
+def customer_statement(customer_id):
+    """Account statement: sales (invoices), payments, running balance.
+
+    Query params:
+        from_date: start date (YYYY-MM-DD), default 30 days ago
+        to_date: end date (YYYY-MM-DD), default today
+    """
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    from_date = request.args.get('from_date')
+    to_date = request.args.get('to_date')
+
+    # Verify customer exists
+    cur.execute("SELECT name, credit_limit, credit_balance FROM customers WHERE id = %s", (customer_id,))
+    cust = cur.fetchone()
+    if not cust:
+        cur.close(); conn.close()
+        return jsonify({'error': 'Customer not found'}), 404
+
+    where_date = ""
+    params = [customer_id]
+    if from_date:
+        where_date += " AND s.created_at >= %s"
+        params.append(from_date)
+    if to_date:
+        where_date += " AND s.created_at < %s::date + interval '1 day'"
+        params.append(to_date)
+
+    # Get credit sales (charges / cargos)
+    cur.execute(f"""
+        SELECT s.id, 'charge' as type, s.total as amount, s.created_at,
+               'Venta #' || s.id as description, s.status
+        FROM sales s
+        WHERE s.customer_id = %s AND s.sale_type = 'credit' {where_date}
+        ORDER BY s.created_at
+    """, params)
+
+    entries = []
+    for r in cur.fetchall():
+        entries.append({
+            'id': r[0], 'type': r[1], 'amount': float(r[2]) if r[2] else 0,
+            'date': str(r[3]), 'description': r[4], 'status': r[5]
+        })
+
+    # Get customer payments (abonos) from the customer_payments table
+    pay_params = [customer_id]
+    pay_where = ""
+    if from_date:
+        pay_where += " AND cp.created_at >= %s"
+        pay_params.append(from_date)
+    if to_date:
+        pay_where += " AND cp.created_at < %s::date + interval '1 day'"
+        pay_params.append(to_date)
+
+    cur.execute(f"""
+        SELECT cp.id, 'payment' as type, cp.amount, cp.created_at,
+               'Abono - ' || cp.payment_method as description, 'completed' as status
+        FROM customer_payments cp
+        WHERE cp.customer_id = %s {pay_where}
+        ORDER BY cp.created_at
+    """, pay_params)
+
+    for r in cur.fetchall():
+        entries.append({
+            'id': r[0], 'type': r[1], 'amount': float(r[2]) if r[2] else 0,
+            'date': str(r[3]), 'description': r[4], 'status': r[5]
+        })
+
+    # Sort all entries by date for correct running balance
+    entries.sort(key=lambda e: e['date'])
+
+    # Compute running balance
+    balance = 0.0
+    for entry in entries:
+        if entry['status'] == 'cancelled':
+            continue
+        if entry['type'] == 'charge':
+            balance += entry['amount']
+        elif entry['type'] == 'payment':
+            balance -= entry['amount']
+        entry['running_balance'] = round(balance, 2)
+
+    cur.close()
+    conn.close()
+
+    return jsonify({
+        'customer': {
+            'id': customer_id,
+            'name': cust[0],
+            'credit_limit': float(cust[1]) if cust[1] else 0,
+            'credit_balance': float(cust[2]) if cust[2] else 0,
+        },
+        'entries': entries,
+        'balance': round(balance, 2),
+    })
+
+
+@customers_bp.route('/<int:customer_id>/vehicles', methods=['GET'])
+@require_auth('customers.view')
+def customer_vehicles(customer_id):
+    """Get customer's vehicle list with last purchases per vehicle.
+
+    Vehicle info is stored as JSONB in customers.vehicle_info:
+    [{make, model, year, vin, plates}, ...]
+    """
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("SELECT vehicle_info FROM customers WHERE id = %s", (customer_id,))
+    row = cur.fetchone()
+    if not row:
+        cur.close(); conn.close()
+        return jsonify({'error': 'Customer not found'}), 404
+
+    vehicles = row[0] or []
+
+    # Get recent purchases for this customer to match with vehicles
+    cur.execute("""
+        SELECT s.id, s.total, s.created_at, s.notes,
+               array_agg(si.name ORDER BY si.id) as items
+        FROM sales s
+        JOIN sale_items si ON si.sale_id = s.id
+        WHERE s.customer_id = %s AND s.status = 'completed'
+        GROUP BY s.id, s.total, s.created_at, s.notes
+        ORDER BY s.created_at DESC
+        LIMIT 50
+    """, (customer_id,))
+
+    recent_sales = []
+    for r in cur.fetchall():
+        recent_sales.append({
+            'sale_id': r[0], 'total': float(r[1]) if r[1] else 0,
+            'date': str(r[2]), 'notes': r[3], 'items': r[4]
+        })
+
+    cur.close()
+    conn.close()
+
+    return jsonify({
+        'vehicles': vehicles,
+        'recent_sales': recent_sales,
+    })
+
+
+@customers_bp.route('/<int:customer_id>/payment', methods=['POST'])
+@require_auth('customers.edit')
+def record_customer_payment(customer_id):
+    """Record a payment against a customer's credit balance (abono).
+
+    Body: {amount: float, payment_method: str, reference: str, register_id: int}
+    """
+    data = request.get_json() or {}
+    amount = float(data.get('amount', 0))
+    payment_method = data.get('payment_method', 'efectivo')
+    reference = data.get('reference', '')
+    register_id = data.get('register_id')
+
+    if amount <= 0:
+        return jsonify({'error': 'Amount must be greater than 0'}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    # Verify customer exists and has a balance
+    cur.execute("SELECT name, credit_balance FROM customers WHERE id = %s", (customer_id,))
+    cust = cur.fetchone()
+    if not cust:
+        cur.close(); conn.close()
+        return jsonify({'error': 'Customer not found'}), 404
+
+    credit_balance = float(cust[1] or 0)
+    if amount > credit_balance:
+        cur.close(); conn.close()
+        return jsonify({
+            'error': f'Payment ${amount:.2f} exceeds current balance ${credit_balance:.2f}'
+        }), 400
+
+    try:
+        # Record the payment
+        cur.execute("""
+            INSERT INTO customer_payments
+                (customer_id, amount, payment_method, reference, employee_id, register_id)
+            VALUES (%s,%s,%s,%s,%s,%s)
+            RETURNING id, created_at
+        """, (
+            customer_id, amount, payment_method, reference,
+            getattr(g, 'employee_id', None), register_id
+        ))
+        payment_id, created_at = cur.fetchone()
+
+        # Reduce customer credit balance
+        new_balance = round(credit_balance - amount, 2)
+        cur.execute("""
+            UPDATE customers SET credit_balance = %s WHERE id = %s
+        """, (new_balance, customer_id))
+
+        # Record cash movement on register if cash payment
+        if register_id and payment_method == 'efectivo':
+            cur.execute("""
+                INSERT INTO cash_movements (register_id, type, amount, reason, employee_id)
+                VALUES (%s, 'in', %s, %s, %s)
+            """, (register_id, amount, f'Abono cliente #{customer_id} - {cust[0]}',
+                  getattr(g, 'employee_id', None)))
+
+        log_action(conn, 'CUSTOMER_PAYMENT', 'customer', customer_id,
+                   old_value={'credit_balance': credit_balance},
+                   new_value={'credit_balance': new_balance, 'payment': amount})
+
+        conn.commit()
+        cur.close(); conn.close()
+
+        return jsonify({
+            'payment_id': payment_id,
+            'amount': amount,
+            'previous_balance': credit_balance,
+            'new_balance': new_balance,
+            'created_at': str(created_at),
+            'message': 'Payment recorded'
+        }), 201
+
+    except Exception as e:
+        conn.rollback()
+        cur.close(); conn.close()
+        return jsonify({'error': str(e)}), 500

pos/migrations/runner.py

@@ -13,7 +13,7 @@ MIGRATIONS_DIR = os.path.dirname(os.path.abspath(__file__))
 # Migration registry: version -> filename
 MIGRATIONS = {
     'v1.0': 'v1.0_initial.sql',
-    # Future: 'v1.1': 'v1.1_add_xyz.sql',
+    'v1.1': 'v1.1_pos_tables.sql',
 }
 
 

pos/migrations/v1.1_pos_tables.sql

@@ -0,0 +1,55 @@
+-- /home/Autopartes/pos/migrations/v1.1_pos_tables.sql
+-- POS Plan 3: Additional tables for sale payments and layaway items.
+-- Run against each tenant DB.
+
+-- Sale payments: tracks individual payment methods for a sale (especially mixed payments)
+CREATE TABLE IF NOT EXISTS sale_payments (
+    id              SERIAL PRIMARY KEY,
+    sale_id         INTEGER REFERENCES sales(id),
+    register_id     INTEGER REFERENCES cash_registers(id),
+    method          VARCHAR(20) NOT NULL,           -- efectivo, transferencia, tarjeta
+    amount          NUMERIC(12,2) NOT NULL,
+    reference       VARCHAR(100),                    -- transaction ref for non-cash
+    created_at      TIMESTAMPTZ DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_sale_payments_sale ON sale_payments(sale_id);
+
+-- Customer payments: tracks credit payments (abonos) against customer balance
+CREATE TABLE IF NOT EXISTS customer_payments (
+    id              SERIAL PRIMARY KEY,
+    customer_id     INTEGER REFERENCES customers(id),
+    amount          NUMERIC(12,2) NOT NULL,
+    payment_method  VARCHAR(20) NOT NULL DEFAULT 'efectivo',
+    reference       VARCHAR(100),
+    employee_id     INTEGER REFERENCES employees(id),
+    register_id     INTEGER REFERENCES cash_registers(id),
+    created_at      TIMESTAMPTZ DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_customer_payments_customer ON customer_payments(customer_id);
+
+-- Layaway items: line items for a layaway (mirrors quotation_items structure)
+CREATE TABLE IF NOT EXISTS layaway_items (
+    id              SERIAL PRIMARY KEY,
+    layaway_id      INTEGER REFERENCES layaways(id),
+    inventory_id    INTEGER REFERENCES inventory(id),
+    part_number     VARCHAR(100),
+    name            VARCHAR(300),
+    quantity        INTEGER NOT NULL,
+    unit_price      NUMERIC(12,2) NOT NULL,
+    discount_pct    NUMERIC(5,2) DEFAULT 0,
+    tax_rate        NUMERIC(5,4) DEFAULT 0.16,
+    subtotal        NUMERIC(12,2) NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_layaway_items_layaway ON layaway_items(layaway_id);
+
+-- Additional indexes for POS query performance
+CREATE INDEX IF NOT EXISTS idx_sales_register ON sales(register_id) WHERE status = 'completed';
+CREATE INDEX IF NOT EXISTS idx_sales_customer ON sales(customer_id);
+CREATE INDEX IF NOT EXISTS idx_sales_created ON sales(created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_sales_branch_date ON sales(branch_id, created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_quotations_customer ON quotations(customer_id);
+CREATE INDEX IF NOT EXISTS idx_layaways_customer ON layaways(customer_id);
+CREATE INDEX IF NOT EXISTS idx_cash_registers_employee ON cash_registers(employee_id) WHERE status = 'open';

pos/services/pos_engine.py

@@ -0,0 +1,488 @@
+# /home/Autopartes/pos/services/pos_engine.py
+"""POS engine: sale processing, totals calculation, pricing, cancellation.
+
+All sale operations go through this service. Stock deductions are delegated
+to inventory_engine.record_sale() — this service NEVER creates inventory
+operations directly.
+
+Monetary amounts: NUMERIC(12,2) in DB, float in Python.
+Tax: 16% IVA per item (from item.tax_rate field).
+"""
+
+from datetime import datetime, timedelta
+from decimal import Decimal, ROUND_HALF_UP
+from flask import g
+from services.audit import log_action
+from services.inventory_engine import (
+    record_sale as inventory_record_sale,
+    record_operation,
+    get_stock,
+)
+
+
+def _to_dec(val):
+    """Convert a value to Decimal for precise arithmetic."""
+    return Decimal(str(val))
+
+
+def calculate_totals(items):
+    """Compute subtotal, discount amounts, tax, and total for a list of items.
+
+    Uses Python Decimal for all intermediate calculations to avoid
+    floating-point accumulation errors. Each line item is rounded
+    individually before summing. Converts back to float only at
+    the end for JSON serialization.
+
+    Each item dict must have: unit_price, quantity, discount_pct, tax_rate.
+    Returns dict with computed values and enriched items list.
+
+    Args:
+        items: list of dicts with keys:
+            - unit_price (float): price per unit
+            - quantity (int): number of units
+            - discount_pct (float): discount percentage (0-100)
+            - tax_rate (float): tax rate as decimal (e.g., 0.16 for 16%)
+
+    Returns:
+        dict: {subtotal, discount_total, tax_total, total, items: [...enriched...]}
+    """
+    subtotal = Decimal('0')
+    discount_total = Decimal('0')
+    tax_total = Decimal('0')
+    enriched_items = []
+    TWO = Decimal('0.01')
+
+    for item in items:
+        qty = int(item['quantity'])
+        price = _to_dec(item['unit_price'])
+        discount_pct = _to_dec(item.get('discount_pct', 0))
+        tax_rate = _to_dec(item.get('tax_rate', '0.16'))
+
+        line_gross = (price * qty).quantize(TWO, rounding=ROUND_HALF_UP)
+        line_discount = (line_gross * discount_pct / Decimal('100')).quantize(TWO, rounding=ROUND_HALF_UP)
+        line_after_discount = (line_gross - line_discount).quantize(TWO, rounding=ROUND_HALF_UP)
+        line_tax = (line_after_discount * tax_rate).quantize(TWO, rounding=ROUND_HALF_UP)
+        line_subtotal = (line_after_discount + line_tax).quantize(TWO, rounding=ROUND_HALF_UP)
+
+        subtotal += line_after_discount
+        discount_total += line_discount
+        tax_total += line_tax
+
+        enriched_items.append({
+            **item,
+            'line_gross': float(line_gross),
+            'discount_amount': float(line_discount),
+            'tax_amount': float(line_tax),
+            'subtotal': float(line_subtotal),
+        })
+
+    return {
+        'subtotal': float(subtotal.quantize(TWO, rounding=ROUND_HALF_UP)),
+        'discount_total': float(discount_total.quantize(TWO, rounding=ROUND_HALF_UP)),
+        'tax_total': float(tax_total.quantize(TWO, rounding=ROUND_HALF_UP)),
+        'total': float((subtotal + tax_total).quantize(TWO, rounding=ROUND_HALF_UP)),
+        'items': enriched_items,
+    }
+
+
+def get_price_for_customer(inventory_item, customer):
+    """Return the correct price based on the customer's price tier.
+
+    Args:
+        inventory_item: dict with price_1, price_2, price_3
+        customer: dict with price_tier (1, 2, or 3), or None for publico general
+
+    Returns:
+        float: the applicable price
+    """
+    if customer is None:
+        return float(inventory_item.get('price_1', 0))
+
+    tier = customer.get('price_tier', 1)
+    if tier == 3:
+        price = inventory_item.get('price_3', 0)
+    elif tier == 2:
+        price = inventory_item.get('price_2', 0)
+    else:
+        price = inventory_item.get('price_1', 0)
+
+    return float(price) if price else float(inventory_item.get('price_1', 0))
+
+
+def get_margin_info(inventory_item, selling_price=None, discount_pct=0):
+    """Return cost, price, margin %, and max discount without losing margin.
+
+    Only meaningful for employees with pos.view_cost permission (checked by caller).
+
+    Args:
+        inventory_item: dict with cost, price_1 (or selling_price override)
+        selling_price: override price (if None, uses price_1)
+        discount_pct: current discount percentage
+
+    Returns:
+        dict: {cost, price, margin_pct, max_discount_pct}
+    """
+    cost = float(inventory_item.get('cost', 0))
+    price = float(selling_price) if selling_price else float(inventory_item.get('price_1', 0))
+
+    if price <= 0:
+        return {'cost': cost, 'price': price, 'margin_pct': 0.0, 'max_discount_pct': 0.0}
+
+    effective_price = price * (1 - discount_pct / 100)
+    margin_pct = ((effective_price - cost) / effective_price * 100) if effective_price > 0 else 0.0
+
+    # Max discount before margin hits zero: price * (1 - d/100) = cost => d = (1 - cost/price) * 100
+    max_discount_pct = ((1 - cost / price) * 100) if price > cost else 0.0
+
+    return {
+        'cost': round(cost, 2),
+        'price': round(price, 2),
+        'margin_pct': round(margin_pct, 2),
+        'max_discount_pct': round(max_discount_pct, 2),
+    }
+
+
+def process_sale(conn, sale_data):
+    """Process a complete sale: validate, create records, deduct inventory, record payment.
+
+    This is the main entry point for creating a sale. It handles the full transaction:
+    1. Validate all items exist and have sufficient stock
+    2. Calculate totals
+    3. Create sale + sale_items records
+    4. Call inventory_engine.record_sale() for each item (stock deduction)
+    5. Record payment on cash register
+    6. Update customer credit balance (if credit sale)
+    7. Create audit log entry
+
+    Args:
+        conn: psycopg2 connection to tenant DB (caller controls commit)
+        sale_data: dict with keys:
+            - items: [{inventory_id, quantity, unit_price, discount_pct, tax_rate}]
+            - customer_id: int or None (publico general)
+            - payment_method: 'efectivo' | 'transferencia' | 'tarjeta' | 'mixto'
+            - sale_type: 'cash' | 'credit' | 'mixed'
+            - register_id: int (cash register session ID)
+            - amount_paid: float
+            - payment_details: [{method, amount, reference}] (for mixed payments)
+            - notes: str (optional)
+
+    Returns:
+        dict: complete sale object with id, items, totals, change
+
+    Raises:
+        ValueError: on validation errors (insufficient stock, invalid items, etc.)
+    """
+    cur = conn.cursor()
+    items = sale_data.get('items', [])
+    customer_id = sale_data.get('customer_id')
+    payment_method = sale_data.get('payment_method', 'efectivo')
+    sale_type = sale_data.get('sale_type', 'cash')
+    register_id = sale_data.get('register_id')
+    amount_paid = float(sale_data.get('amount_paid', 0))
+    payment_details = sale_data.get('payment_details', [])
+    notes = sale_data.get('notes')
+    branch_id = getattr(g, 'branch_id', None)
+    employee_id = getattr(g, 'employee_id', None)
+
+    if not items:
+        raise ValueError("No items in sale")
+
+    # Validate register is open
+    if register_id:
+        cur.execute("SELECT status FROM cash_registers WHERE id = %s", (register_id,))
+        reg = cur.fetchone()
+        if not reg or reg[0] != 'open':
+            raise ValueError("Cash register is not open")
+
+    # Validate and enrich items from inventory
+    enriched_items = []
+    for item in items:
+        inv_id = item.get('inventory_id')
+        qty = int(item.get('quantity', 1))
+        if qty <= 0:
+            raise ValueError(f"Invalid quantity for inventory_id {inv_id}")
+
+        cur.execute("""
+            SELECT id, part_number, name, cost, price_1, price_2, price_3,
+                   tax_rate, branch_id
+            FROM inventory WHERE id = %s AND is_active = true
+        """, (inv_id,))
+        inv = cur.fetchone()
+        if not inv:
+            raise ValueError(f"Inventory item {inv_id} not found or inactive")
+
+        # Check stock (allow negative stock for offline tolerance, but warn)
+        current_stock = get_stock(conn, inv_id, inv[8])  # inv[8] = branch_id
+
+        # Use provided price or fetch from inventory
+        unit_price = float(item.get('unit_price', inv[4]))  # default to price_1
+        discount_pct = float(item.get('discount_pct', 0))
+        tax_rate = float(item.get('tax_rate', inv[7] or 0.16))
+        unit_cost = float(inv[3]) if inv[3] else 0
+
+        # Validate discount against employee max
+        max_discount = float(getattr(g, 'max_discount_pct', 100) or 100)
+        if g.employee_role not in ('owner', 'admin') and discount_pct > max_discount:
+            raise ValueError(
+                f"Discount {discount_pct}% exceeds your maximum allowed {max_discount}% "
+                f"for item {inv[2]}"
+            )
+
+        enriched_items.append({
+            'inventory_id': inv_id,
+            'part_number': inv[1],
+            'name': inv[2],
+            'quantity': qty,
+            'unit_price': unit_price,
+            'unit_cost': unit_cost,
+            'discount_pct': discount_pct,
+            'tax_rate': tax_rate,
+            'branch_id': inv[8],
+            'stock_before': current_stock,
+        })
+
+    # Calculate totals
+    totals = calculate_totals(enriched_items)
+
+    # Validate credit sale
+    if sale_type == 'credit' and customer_id:
+        cur.execute("SELECT credit_limit, credit_balance FROM customers WHERE id = %s", (customer_id,))
+        cust = cur.fetchone()
+        if cust:
+            credit_limit = float(cust[0] or 0)
+            credit_balance = float(cust[1] or 0)
+            credit_available = credit_limit - credit_balance
+            if totals['total'] > credit_available and credit_limit > 0:
+                raise ValueError(
+                    f"Insufficient credit. Available: ${credit_available:.2f}, "
+                    f"Required: ${totals['total']:.2f}"
+                )
+
+    # Calculate change
+    change_given = 0.0
+    if sale_type == 'cash' and payment_method == 'efectivo':
+        change_given = round(max(amount_paid - totals['total'], 0), 2)
+
+    # SAT payment method codes
+    metodo_pago_sat = 'PPD' if sale_type == 'credit' else 'PUE'
+    forma_pago_map = {
+        'efectivo': '01', 'transferencia': '03', 'tarjeta': '04', 'mixto': '99'
+    }
+    forma_pago_sat = forma_pago_map.get(payment_method, '99')
+
+    # Create sale record
+    cur.execute("""
+        INSERT INTO sales
+            (branch_id, customer_id, employee_id, register_id, sale_type,
+             payment_method, subtotal, discount_total, tax_total, total,
+             amount_paid, change_given, metodo_pago_sat, forma_pago_sat,
+             status, device_id, notes)
+        VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,'completed',%s,%s)
+        RETURNING id, created_at
+    """, (
+        branch_id, customer_id, employee_id, register_id, sale_type,
+        payment_method, totals['subtotal'], totals['discount_total'],
+        totals['tax_total'], totals['total'], amount_paid, change_given,
+        metodo_pago_sat, forma_pago_sat,
+        getattr(g, 'device_id', None), notes
+    ))
+    sale_id, created_at = cur.fetchone()
+
+    # Create sale items and deduct inventory
+    sale_items = []
+    for idx, item in enumerate(totals['items']):
+        cur.execute("""
+            INSERT INTO sale_items
+                (sale_id, inventory_id, part_number, name, quantity,
+                 unit_price, unit_cost, discount_pct, discount_amount,
+                 tax_rate, tax_amount, subtotal)
+            VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)
+            RETURNING id
+        """, (
+            sale_id, item['inventory_id'], item['part_number'], item['name'],
+            item['quantity'], item['unit_price'], item.get('unit_cost', 0),
+            item['discount_pct'], item['discount_amount'],
+            item['tax_rate'], item['tax_amount'], item['subtotal']
+        ))
+        sale_item_id = cur.fetchone()[0]
+
+        # Deduct inventory via inventory_engine (NEVER create operations directly)
+        inventory_record_sale(
+            conn,
+            item['inventory_id'],
+            item.get('branch_id', branch_id),
+            item['quantity'],
+            sale_id=sale_id,
+            cost_at_time=item.get('unit_cost')
+        )
+
+        sale_items.append({
+            'id': sale_item_id,
+            'inventory_id': item['inventory_id'],
+            'part_number': item['part_number'],
+            'name': item['name'],
+            'quantity': item['quantity'],
+            'unit_price': item['unit_price'],
+            'unit_cost': item.get('unit_cost', 0),
+            'discount_pct': item['discount_pct'],
+            'discount_amount': item['discount_amount'],
+            'tax_rate': item['tax_rate'],
+            'tax_amount': item['tax_amount'],
+            'subtotal': item['subtotal'],
+        })
+
+    # Record payment on cash register (cash movements for efectivo)
+    if register_id and payment_details:
+        for pd in payment_details:
+            method = pd.get('method', payment_method)
+            amt = float(pd.get('amount', 0))
+            ref = pd.get('reference', '')
+            cur.execute("""
+                INSERT INTO sale_payments
+                    (sale_id, register_id, method, amount, reference)
+                VALUES (%s,%s,%s,%s,%s)
+            """, (sale_id, register_id, method, amt, ref))
+    elif register_id:
+        cur.execute("""
+            INSERT INTO sale_payments
+                (sale_id, register_id, method, amount, reference)
+            VALUES (%s,%s,%s,%s,%s)
+        """, (sale_id, register_id, payment_method, amount_paid, sale_data.get('reference', '')))
+
+    # Update customer credit balance if credit sale
+    if sale_type == 'credit' and customer_id:
+        cur.execute("""
+            UPDATE customers
+            SET credit_balance = credit_balance + %s
+            WHERE id = %s
+        """, (totals['total'], customer_id))
+
+    # Audit log
+    log_action(conn, 'SALE', 'sale', sale_id,
+               new_value={
+                   'total': totals['total'],
+                   'items_count': len(sale_items),
+                   'payment_method': payment_method,
+                   'sale_type': sale_type,
+                   'customer_id': customer_id,
+               })
+
+    cur.close()
+
+    return {
+        'id': sale_id,
+        'branch_id': branch_id,
+        'customer_id': customer_id,
+        'employee_id': employee_id,
+        'register_id': register_id,
+        'sale_type': sale_type,
+        'payment_method': payment_method,
+        'subtotal': totals['subtotal'],
+        'discount_total': totals['discount_total'],
+        'tax_total': totals['tax_total'],
+        'total': totals['total'],
+        'amount_paid': amount_paid,
+        'change_given': change_given,
+        'metodo_pago_sat': metodo_pago_sat,
+        'forma_pago_sat': forma_pago_sat,
+        'status': 'completed',
+        'items': sale_items,
+        'created_at': str(created_at),
+    }
+
+
+def cancel_sale(conn, sale_id, reason):
+    """Cancel a sale: validate permissions, reverse inventory, update credit.
+
+    Business rules:
+    - Cashiers can only cancel their own sales within 30 minutes
+    - Admins and owners can cancel any sale
+    - Cancelled sales are not deleted, just marked as 'cancelled'
+    - Inventory is restored via RETURN operations
+    - Customer credit balance is adjusted back
+
+    Args:
+        conn: psycopg2 connection
+        sale_id: int
+        reason: str (mandatory, min 3 chars)
+
+    Returns:
+        dict: cancellation result
+
+    Raises:
+        ValueError: on validation errors
+    """
+    if not reason or len(reason.strip()) < 3:
+        raise ValueError("Cancellation reason is mandatory (min 3 characters)")
+
+    cur = conn.cursor()
+
+    # Get sale details
+    cur.execute("""
+        SELECT id, employee_id, customer_id, sale_type, total, status, created_at,
+               branch_id, register_id
+        FROM sales WHERE id = %s
+    """, (sale_id,))
+    sale = cur.fetchone()
+    if not sale:
+        raise ValueError("Sale not found")
+
+    s_id, s_emp_id, s_cust_id, s_type, s_total, s_status, s_created, s_branch, s_register = sale
+
+    if s_status == 'cancelled':
+        raise ValueError("Sale is already cancelled")
+
+    # Permission check: cashiers can only cancel own sales within 30 min
+    role = getattr(g, 'employee_role', 'cashier')
+    emp_id = getattr(g, 'employee_id', None)
+
+    if role == 'cashier':
+        if s_emp_id != emp_id:
+            raise ValueError("Cashiers can only cancel their own sales")
+        if datetime.utcnow() - s_created > timedelta(minutes=30):
+            raise ValueError("Cashiers can only cancel sales within 30 minutes of creation")
+
+    # Get sale items for inventory reversal
+    cur.execute("""
+        SELECT inventory_id, quantity, unit_cost
+        FROM sale_items WHERE sale_id = %s
+    """, (sale_id,))
+    sale_items = cur.fetchall()
+
+    # Reverse inventory: create RETURN operations (positive quantity)
+    from services.inventory_engine import record_return
+    for inv_id, qty, cost in sale_items:
+        record_return(
+            conn, inv_id, s_branch, qty,
+            sale_id=sale_id,
+            notes=f"Cancelacion venta #{sale_id}: {reason}"
+        )
+
+    # Update sale status
+    cur.execute("""
+        UPDATE sales SET status = 'cancelled', notes = COALESCE(notes || ' | ', '') || %s
+        WHERE id = %s
+    """, (f"CANCELADA: {reason}", sale_id))
+
+    # Reverse customer credit balance if credit sale
+    if s_type == 'credit' and s_cust_id:
+        cur.execute("""
+            UPDATE customers
+            SET credit_balance = credit_balance - %s
+            WHERE id = %s
+        """, (float(s_total), s_cust_id))
+
+    # Audit log
+    log_action(conn, 'CANCEL', 'sale', sale_id,
+               old_value={'status': 'completed', 'total': float(s_total)},
+               new_value={'status': 'cancelled', 'reason': reason})
+
+    cur.close()
+
+    return {
+        'sale_id': sale_id,
+        'status': 'cancelled',
+        'reason': reason,
+        'items_reversed': len(sale_items),
+        'total_reversed': float(s_total),
+    }

pos/static/js/customers.js

@@ -0,0 +1,307 @@
+// /home/Autopartes/pos/static/js/customers.js
+/**
+ * Customers management frontend.
+ * Communicates with /pos/api/customers (customers_bp).
+ */
+const Customers = (() => {
+    let token = localStorage.getItem('pos_token') || '';
+    let currentPage = 1;
+    let currentCustomer = null;
+    let searchTimeout = null;
+
+    const fmt = (n) => '$' + parseFloat(n || 0).toLocaleString('es-MX', {
+        minimumFractionDigits: 2, maximumFractionDigits: 2
+    });
+
+    function headers() {
+        return { 'Content-Type': 'application/json', 'Authorization': 'Bearer ' + token };
+    }
+
+    async function api(url, options = {}) {
+        options.headers = headers();
+        const res = await fetch(url, options);
+        const data = await res.json();
+        if (!res.ok) throw new Error(data.error || `HTTP ${res.status}`);
+        return data;
+    }
+
+    // ─── List ────────────────────────────
+    async function loadCustomers(page, q) {
+        page = page || currentPage;
+        q = q !== undefined ? q : (document.getElementById('searchInput').value || '');
+
+        try {
+            const params = new URLSearchParams({ page, per_page: 50 });
+            if (q) params.append('q', q);
+
+            const data = await api(`/pos/api/customers?${params}`);
+            renderTable(data.data);
+            renderPagination(data.pagination);
+        } catch (e) {
+            console.error('Load customers failed:', e);
+        }
+    }
+
+    function renderTable(customers) {
+        const tbody = document.getElementById('customersBody');
+        const tiers = { 1: ['Mostrador', 'tier-1'], 2: ['Taller', 'tier-2'], 3: ['Mayoreo', 'tier-3'] };
+
+        let html = '';
+        customers.forEach(c => {
+            const [tierName, tierClass] = tiers[c.price_tier] || ['P1', 'tier-1'];
+            const limit = c.credit_limit || 0;
+            const balance = c.credit_balance || 0;
+            const usagePct = limit > 0 ? Math.min(100, (balance / limit) * 100) : 0;
+            const fillClass = usagePct > 90 ? 'danger' : usagePct > 70 ? 'warning' : '';
+
+            html += `<tr onclick="Customers.showDetail(${c.id})">
+                <td><strong>${c.name}</strong></td>
+                <td>${c.rfc || '-'}</td>
+                <td>${c.phone || '-'}</td>
+                <td><span class="tier-badge ${tierClass}">${tierName}</span></td>
+                <td>${fmt(limit)}
+                    ${limit > 0 ? `<div class="credit-bar"><div class="credit-fill ${fillClass}" style="width:${usagePct}%"></div></div>` : ''}
+                </td>
+                <td>${balance > 0 ? fmt(balance) : '-'}</td>
+            </tr>`;
+        });
+
+        if (customers.length === 0) {
+            html = '<tr><td colspan="6" style="text-align:center;color:#999;padding:20px;">Sin resultados</td></tr>';
+        }
+
+        tbody.innerHTML = html;
+    }
+
+    function renderPagination(pag) {
+        const container = document.getElementById('pagination');
+        if (pag.total_pages <= 1) { container.innerHTML = ''; return; }
+
+        let html = '';
+        if (pag.page > 1) {
+            html += `<button class="btn btn-secondary" onclick="Customers.goToPage(${pag.page - 1})">Anterior</button>`;
+        }
+        for (let i = 1; i <= Math.min(pag.total_pages, 10); i++) {
+            html += `<button class="btn ${i === pag.page ? 'active' : 'btn-secondary'}" onclick="Customers.goToPage(${i})">${i}</button>`;
+        }
+        if (pag.page < pag.total_pages) {
+            html += `<button class="btn btn-secondary" onclick="Customers.goToPage(${pag.page + 1})">Siguiente</button>`;
+        }
+        container.innerHTML = html;
+    }
+
+    function goToPage(page) {
+        currentPage = page;
+        loadCustomers(page);
+    }
+
+    function search() {
+        clearTimeout(searchTimeout);
+        searchTimeout = setTimeout(() => {
+            currentPage = 1;
+            loadCustomers(1);
+        }, 300);
+    }
+
+    // ─── Detail ──────────────────────────
+    async function showDetail(id) {
+        try {
+            const c = await api(`/pos/api/customers/${id}`);
+            currentCustomer = c;
+
+            document.getElementById('detailName').textContent = c.name;
+
+            // Credit
+            const available = (c.credit_limit || 0) - (c.credit_balance || 0);
+            document.getElementById('detailCreditAvailable').textContent = fmt(available);
+            document.getElementById('detailCreditLimit').textContent = fmt(c.credit_limit);
+            document.getElementById('detailCreditBalance').textContent = fmt(c.credit_balance);
+
+            // Fiscal
+            let fiscalHtml = '';
+            fiscalHtml += `<div class="detail-field"><span class="label">RFC</span><span>${c.rfc || '-'}</span></div>`;
+            fiscalHtml += `<div class="detail-field"><span class="label">Razon Social</span><span>${c.razon_social || '-'}</span></div>`;
+            fiscalHtml += `<div class="detail-field"><span class="label">Regimen</span><span>${c.regimen_fiscal || '-'}</span></div>`;
+            fiscalHtml += `<div class="detail-field"><span class="label">Uso CFDI</span><span>${c.uso_cfdi || '-'}</span></div>`;
+            fiscalHtml += `<div class="detail-field"><span class="label">CP</span><span>${c.cp || '-'}</span></div>`;
+            document.getElementById('detailFiscal').innerHTML = fiscalHtml;
+
+            // Contact
+            let contactHtml = '';
+            contactHtml += `<div class="detail-field"><span class="label">Telefono</span><span>${c.phone || '-'}</span></div>`;
+            contactHtml += `<div class="detail-field"><span class="label">Email</span><span>${c.email || '-'}</span></div>`;
+            contactHtml += `<div class="detail-field"><span class="label">Direccion</span><span>${c.address || '-'}</span></div>`;
+            document.getElementById('detailContact').innerHTML = contactHtml;
+
+            // Vehicles
+            const vehicles = c.vehicle_info || [];
+            if (vehicles.length === 0) {
+                document.getElementById('detailVehicles').innerHTML = '<div style="color:#999;font-size:13px;">Sin vehiculos registrados</div>';
+            } else {
+                document.getElementById('detailVehicles').innerHTML = vehicles.map(v =>
+                    `<div class="vehicle-card">
+                        <strong>${v.make || ''} ${v.model || ''} ${v.year || ''}</strong>
+                        ${v.plates ? `<span style="margin-left:8px;color:#666;">Placas: ${v.plates}</span>` : ''}
+                        ${v.vin ? `<div style="font-size:11px;color:#999;">VIN: ${v.vin}</div>` : ''}
+                    </div>`
+                ).join('');
+            }
+
+            // Recent purchases
+            const purchases = c.recent_purchases || [];
+            if (purchases.length === 0) {
+                document.getElementById('detailPurchases').innerHTML = '<div style="color:#999;font-size:13px;">Sin compras recientes</div>';
+            } else {
+                document.getElementById('detailPurchases').innerHTML = purchases.map(p =>
+                    `<div class="purchase-item">
+                        <span>Venta #${p.id} - ${new Date(p.created_at).toLocaleDateString('es-MX')}</span>
+                        <span>${fmt(p.total)}</span>
+                    </div>`
+                ).join('');
+            }
+
+            document.getElementById('detailPanel').classList.add('active');
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    function closeDetail() {
+        document.getElementById('detailPanel').classList.remove('active');
+        currentCustomer = null;
+    }
+
+    // ─── Create/Edit Modal ───────────────
+    function showCreateModal() {
+        document.getElementById('modalTitle').textContent = 'Nuevo Cliente';
+        document.getElementById('editId').value = '';
+        document.getElementById('fName').value = '';
+        document.getElementById('fRfc').value = '';
+        document.getElementById('fRazonSocial').value = '';
+        document.getElementById('fRegimenFiscal').value = '';
+        document.getElementById('fUsoCfdi').value = 'G03';
+        document.getElementById('fCp').value = '';
+        document.getElementById('fPhone').value = '';
+        document.getElementById('fEmail').value = '';
+        document.getElementById('fAddress').value = '';
+        document.getElementById('fPriceTier').value = '1';
+        document.getElementById('fCreditLimit').value = '0';
+        document.getElementById('customerModal').classList.add('active');
+        document.getElementById('fName').focus();
+    }
+
+    function editCurrent() {
+        if (!currentCustomer) return;
+        const c = currentCustomer;
+        document.getElementById('modalTitle').textContent = 'Editar Cliente';
+        document.getElementById('editId').value = c.id;
+        document.getElementById('fName').value = c.name || '';
+        document.getElementById('fRfc').value = c.rfc || '';
+        document.getElementById('fRazonSocial').value = c.razon_social || '';
+        document.getElementById('fRegimenFiscal').value = c.regimen_fiscal || '';
+        document.getElementById('fUsoCfdi').value = c.uso_cfdi || 'G03';
+        document.getElementById('fCp').value = c.cp || '';
+        document.getElementById('fPhone').value = c.phone || '';
+        document.getElementById('fEmail').value = c.email || '';
+        document.getElementById('fAddress').value = c.address || '';
+        document.getElementById('fPriceTier').value = c.price_tier || '1';
+        document.getElementById('fCreditLimit').value = c.credit_limit || 0;
+        document.getElementById('customerModal').classList.add('active');
+    }
+
+    function closeModal() {
+        document.getElementById('customerModal').classList.remove('active');
+    }
+
+    async function save() {
+        const name = document.getElementById('fName').value.trim();
+        if (!name) { alert('Nombre es requerido'); return; }
+
+        const body = {
+            name: name,
+            rfc: document.getElementById('fRfc').value.trim() || null,
+            razon_social: document.getElementById('fRazonSocial').value.trim() || null,
+            regimen_fiscal: document.getElementById('fRegimenFiscal').value || null,
+            uso_cfdi: document.getElementById('fUsoCfdi').value || 'G03',
+            cp: document.getElementById('fCp').value.trim() || null,
+            phone: document.getElementById('fPhone').value.trim() || null,
+            email: document.getElementById('fEmail').value.trim() || null,
+            address: document.getElementById('fAddress').value.trim() || null,
+            price_tier: parseInt(document.getElementById('fPriceTier').value) || 1,
+            credit_limit: parseFloat(document.getElementById('fCreditLimit').value) || 0,
+        };
+
+        const editId = document.getElementById('editId').value;
+
+        try {
+            if (editId) {
+                await api(`/pos/api/customers/${editId}`, {
+                    method: 'PUT',
+                    body: JSON.stringify(body),
+                });
+            } else {
+                await api('/pos/api/customers', {
+                    method: 'POST',
+                    body: JSON.stringify(body),
+                });
+            }
+
+            closeModal();
+            loadCustomers();
+            if (editId && currentCustomer) {
+                showDetail(editId);
+            }
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    // ─── Statement ───────────────────────
+    async function showStatement() {
+        if (!currentCustomer) return;
+        document.getElementById('statementName').textContent = currentCustomer.name;
+
+        try {
+            const data = await api(`/pos/api/customers/${currentCustomer.id}/statement`);
+
+            let html = `<div style="margin-bottom:12px;font-size:14px;">
+                <strong>Saldo actual: ${fmt(data.balance)}</strong> |
+                Limite: ${fmt(data.customer.credit_limit)}
+            </div>`;
+
+            if (data.entries.length === 0) {
+                html += '<div style="color:#999;padding:20px;text-align:center;">Sin movimientos</div>';
+            } else {
+                html += '<table style="width:100%;border-collapse:collapse;font-size:13px;">';
+                html += '<tr style="background:#f5f5f5;"><th style="padding:8px;text-align:left;">Fecha</th><th style="text-align:left;">Concepto</th><th style="text-align:right;padding:8px;">Cargo</th><th style="text-align:right;padding:8px;">Abono</th><th style="text-align:right;padding:8px;">Saldo</th></tr>';
+
+                data.entries.forEach(e => {
+                    const dateStr = new Date(e.date).toLocaleDateString('es-MX');
+                    html += `<tr style="border-bottom:1px solid #eee;">
+                        <td style="padding:6px 8px;">${dateStr}</td>
+                        <td>${e.description}</td>
+                        <td style="text-align:right;padding:6px 8px;">${e.type === 'charge' ? fmt(e.amount) : ''}</td>
+                        <td style="text-align:right;padding:6px 8px;">${e.type === 'payment' ? fmt(e.amount) : ''}</td>
+                        <td style="text-align:right;padding:6px 8px;">${fmt(e.running_balance)}</td>
+                    </tr>`;
+                });
+                html += '</table>';
+            }
+
+            document.getElementById('statementContent').innerHTML = html;
+            document.getElementById('statementModal').classList.add('active');
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    // ─── Init ────────────────────────────
+    loadCustomers();
+
+    return {
+        search, goToPage, loadCustomers,
+        showDetail, closeDetail,
+        showCreateModal, editCurrent, closeModal, save,
+        showStatement,
+    };
+})();

pos/static/js/pos.js

@@ -0,0 +1,928 @@
+// /home/Autopartes/pos/static/js/pos.js
+/**
+ * POS Frontend: sale processing, F-key shortcuts, payment modal, ticket printing.
+ *
+ * Communicates with:
+ *   - /pos/api/sales (pos_bp)
+ *   - /pos/api/quotations (pos_bp)
+ *   - /pos/api/layaways (pos_bp)
+ *   - /pos/api/customers (customers_bp)
+ *   - /pos/api/register (cashregister_bp)
+ *   - /pos/api/inventory/items (inventory_bp) — for item search
+ *   - /pos/api/catalog/search (catalog_bp) — for catalog search
+ */
+const POS = (() => {
+    // ─── State ───────────────────────────
+    let token = localStorage.getItem('pos_token') || '';
+    let cart = [];
+    let selectedRow = -1;
+    let currentCustomer = null;
+    let currentRegister = null;
+    let paymentMethod = 'efectivo';
+    let canViewCost = false;
+    let employeeMaxDiscount = 100;
+    let lastSaleId = null;
+    let searchTimeout = null;
+    let customerSearchTimeout = null;
+
+    const fmt = (n) => '$' + parseFloat(n || 0).toLocaleString('es-MX', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
+
+    function headers() {
+        return { 'Content-Type': 'application/json', 'Authorization': 'Bearer ' + token };
+    }
+
+    async function api(url, options = {}) {
+        options.headers = headers();
+        const res = await fetch(url, options);
+        const data = await res.json();
+        if (!res.ok) throw new Error(data.error || `HTTP ${res.status}`);
+        return data;
+    }
+
+    // ─── Init ────────────────────────────
+    async function init() {
+        // Parse JWT to get employee info
+        try {
+            const payload = JSON.parse(atob(token.split('.')[1]));
+            document.getElementById('employeeName').textContent = payload.name || 'Empleado';
+            document.getElementById('branchName').textContent = payload.branch_name || '';
+            canViewCost = (payload.permissions || []).includes('pos.view_cost');
+            employeeMaxDiscount = payload.max_discount_pct || 100;
+
+            // Show cost/margin columns if permission
+            if (canViewCost) {
+                document.getElementById('thCost').style.display = '';
+                document.getElementById('thMargin').style.display = '';
+            }
+        } catch (e) {
+            console.warn('Could not parse token:', e);
+        }
+
+        // Load cart from localStorage (from catalog)
+        const catalogCart = localStorage.getItem('pos_cart');
+        if (catalogCart) {
+            try {
+                const items = JSON.parse(catalogCart);
+                for (const item of items) {
+                    addToCart(item);
+                }
+                localStorage.removeItem('pos_cart');
+            } catch (e) { console.warn('Could not load catalog cart:', e); }
+        }
+
+        // Load current register
+        await loadRegister();
+
+        // Setup event listeners
+        setupKeyboard();
+        setupSearch();
+        setupCustomerSearch();
+    }
+
+    // ─── Register ────────────────────────
+    async function loadRegister() {
+        try {
+            const data = await api('/pos/api/register/current');
+            if (data.register) {
+                currentRegister = data.register;
+                document.getElementById('registerInfo').innerHTML =
+                    `<span>Caja #${data.register.register_number}</span>`;
+                document.getElementById('registerInfo').classList.remove('no-register');
+            } else {
+                document.getElementById('registerInfo').innerHTML =
+                    '<span>Sin caja abierta</span>';
+                document.getElementById('registerInfo').classList.add('no-register');
+            }
+        } catch (e) {
+            console.warn('Register check failed:', e);
+        }
+    }
+
+    // ─── Cart ────────────────────────────
+    function addToCart(item) {
+        // Check if item already in cart
+        const existing = cart.find(c => c.inventory_id === item.inventory_id);
+        if (existing) {
+            existing.quantity += (item.quantity || 1);
+            renderCart();
+            return;
+        }
+
+        cart.push({
+            inventory_id: item.inventory_id || item.id,
+            part_number: item.part_number || '',
+            name: item.name || '',
+            quantity: item.quantity || 1,
+            unit_price: parseFloat(item.unit_price || item.price_1 || 0),
+            unit_cost: parseFloat(item.cost || 0),
+            discount_pct: parseFloat(item.discount_pct || 0),
+            tax_rate: parseFloat(item.tax_rate || 0.16),
+            stock: item.stock || 0,
+        });
+
+        renderCart();
+    }
+
+    function removeFromCart(index) {
+        cart.splice(index, 1);
+        if (selectedRow >= cart.length) selectedRow = cart.length - 1;
+        renderCart();
+    }
+
+    function renderCart() {
+        const tbody = document.getElementById('cartBody');
+        const table = document.getElementById('cartTable');
+        const empty = document.getElementById('cartEmpty');
+
+        if (cart.length === 0) {
+            table.style.display = 'none';
+            empty.style.display = 'flex';
+            updateTotals();
+            return;
+        }
+
+        table.style.display = '';
+        empty.style.display = 'none';
+
+        let html = '';
+        cart.forEach((item, i) => {
+            const lineGross = item.unit_price * item.quantity;
+            const lineDiscount = lineGross * item.discount_pct / 100;
+            const lineSubtotal = lineGross - lineDiscount;
+
+            const costHtml = canViewCost ? `<td class="num">${fmt(item.unit_cost)}</td>` : '';
+            let marginHtml = '';
+            if (canViewCost) {
+                const effectivePrice = item.unit_price * (1 - item.discount_pct / 100);
+                const marginPct = effectivePrice > 0
+                    ? ((effectivePrice - item.unit_cost) / effectivePrice * 100).toFixed(1)
+                    : '0.0';
+                const cls = parseFloat(marginPct) < 5 ? 'margin-warning' : 'margin-info';
+                marginHtml = `<td class="num"><span class="${cls}">${marginPct}%</span></td>`;
+            }
+
+            html += `<tr class="${i === selectedRow ? 'selected' : ''}" onclick="POS.selectRow(${i})">
+                <td>${i + 1}</td>
+                <td>
+                    <div class="part-name">${item.name}</div>
+                    <div class="part-number">${item.part_number} | Stock: ${item.stock}</div>
+                </td>
+                <td><input type="number" class="qty-input" value="${item.quantity}" min="1"
+                    onchange="POS.updateQty(${i}, this.value)" onclick="event.stopPropagation()"></td>
+                <td class="num">${fmt(item.unit_price)}</td>
+                <td><input type="number" class="discount-input" value="${item.discount_pct}" min="0" max="100" step="0.5"
+                    onchange="POS.updateDiscount(${i}, this.value)" onclick="event.stopPropagation()">%</td>
+                <td class="num">${fmt(lineSubtotal)}</td>
+                ${costHtml}
+                ${marginHtml}
+                <td><button class="btn-remove" onclick="event.stopPropagation(); POS.removeFromCart(${i})">&times;</button></td>
+            </tr>`;
+        });
+        tbody.innerHTML = html;
+        updateTotals();
+    }
+
+    function updateQty(index, val) {
+        const qty = Math.max(1, parseInt(val) || 1);
+        cart[index].quantity = qty;
+        renderCart();
+    }
+
+    function updateDiscount(index, val) {
+        let disc = Math.max(0, Math.min(100, parseFloat(val) || 0));
+        if (disc > employeeMaxDiscount) {
+            alert(`Descuento maximo permitido: ${employeeMaxDiscount}%`);
+            disc = employeeMaxDiscount;
+        }
+        cart[index].discount_pct = disc;
+        renderCart();
+    }
+
+    function selectRow(index) {
+        selectedRow = index;
+        renderCart();
+    }
+
+    function updateTotals() {
+        let subtotal = 0, discountTotal = 0, taxTotal = 0;
+
+        cart.forEach(item => {
+            const lineGross = item.unit_price * item.quantity;
+            const lineDiscount = lineGross * item.discount_pct / 100;
+            const lineAfterDiscount = lineGross - lineDiscount;
+            const lineTax = lineAfterDiscount * item.tax_rate;
+            subtotal += lineAfterDiscount;
+            discountTotal += lineDiscount;
+            taxTotal += lineTax;
+        });
+
+        const total = subtotal + taxTotal;
+
+        document.getElementById('dispSubtotal').textContent = fmt(subtotal);
+        document.getElementById('dispTax').textContent = fmt(taxTotal);
+        document.getElementById('dispTotal').textContent = fmt(total);
+
+        if (discountTotal > 0) {
+            document.getElementById('discountRow').style.display = '';
+            document.getElementById('dispDiscount').textContent = '-' + fmt(discountTotal);
+        } else {
+            document.getElementById('discountRow').style.display = 'none';
+        }
+    }
+
+    function getTotal() {
+        let subtotal = 0, taxTotal = 0;
+        cart.forEach(item => {
+            const lineGross = item.unit_price * item.quantity;
+            const lineDiscount = lineGross * item.discount_pct / 100;
+            const lineAfterDiscount = lineGross - lineDiscount;
+            const lineTax = lineAfterDiscount * item.tax_rate;
+            subtotal += lineAfterDiscount;
+            taxTotal += lineTax;
+        });
+        return Math.round((subtotal + taxTotal) * 100) / 100;
+    }
+
+    // ─── Search ──────────────────────────
+    function setupSearch() {
+        const input = document.getElementById('itemSearch');
+        input.addEventListener('input', () => {
+            clearTimeout(searchTimeout);
+            searchTimeout = setTimeout(() => searchItems(input.value.trim()), 300);
+        });
+        input.addEventListener('keydown', (e) => {
+            if (e.key === 'Enter') {
+                e.preventDefault();
+                searchItems(input.value.trim());
+            }
+            if (e.key === 'Escape') {
+                input.value = '';
+                hideSearchResults();
+            }
+        });
+    }
+
+    async function searchItems(q) {
+        if (!q || q.length < 2) { hideSearchResults(); return; }
+
+        try {
+            const data = await api(`/pos/api/inventory/items?q=${encodeURIComponent(q)}&per_page=20`);
+            const container = document.getElementById('searchResults');
+            const totals = document.getElementById('totalsPanel');
+
+            if (data.data.length === 0) {
+                container.innerHTML = '<div style="padding:20px;text-align:center;color:#999;">Sin resultados</div>';
+            } else {
+                let html = '';
+                data.data.forEach(item => {
+                    // Determine price for current customer
+                    let price = item.price_1;
+                    if (currentCustomer) {
+                        const tier = currentCustomer.price_tier || 1;
+                        price = tier === 3 ? item.price_3 : tier === 2 ? item.price_2 : item.price_1;
+                    }
+                    const stockClass = item.stock <= 0 ? 'zero' : '';
+                    html += `<div class="search-result-item" onclick='POS.addFromSearch(${JSON.stringify(item).replace(/'/g, "&#39;")}, ${price})'>
+                        <div>
+                            <div class="sr-name">${item.name}</div>
+                            <div class="sr-pn">${item.part_number} | ${item.brand || ''}</div>
+                            <div class="sr-stock ${stockClass}">Stock: ${item.stock}</div>
+                        </div>
+                        <div class="sr-price">${fmt(price)}</div>
+                    </div>`;
+                });
+                container.innerHTML = html;
+            }
+
+            container.classList.add('active');
+            totals.classList.add('hidden');
+        } catch (e) {
+            console.error('Search error:', e);
+        }
+    }
+
+    function addFromSearch(item, price) {
+        addToCart({
+            inventory_id: item.id,
+            part_number: item.part_number,
+            name: item.name,
+            unit_price: price,
+            cost: item.cost,
+            tax_rate: item.tax_rate,
+            stock: item.stock,
+        });
+        hideSearchResults();
+        document.getElementById('itemSearch').value = '';
+        document.getElementById('itemSearch').focus();
+    }
+
+    function hideSearchResults() {
+        document.getElementById('searchResults').classList.remove('active');
+        document.getElementById('totalsPanel').classList.remove('hidden');
+    }
+
+    // ─── Customer Search ─────────────────
+    function setupCustomerSearch() {
+        const input = document.getElementById('customerSearch');
+        input.addEventListener('input', () => {
+            clearTimeout(customerSearchTimeout);
+            customerSearchTimeout = setTimeout(() => searchCustomers(input.value.trim()), 300);
+        });
+        input.addEventListener('keydown', (e) => {
+            if (e.key === 'Escape') {
+                input.value = '';
+                document.getElementById('customerAutocomplete').style.display = 'none';
+            }
+        });
+    }
+
+    async function searchCustomers(q) {
+        if (!q || q.length < 2) {
+            document.getElementById('customerAutocomplete').style.display = 'none';
+            return;
+        }
+
+        try {
+            const data = await api(`/pos/api/customers?q=${encodeURIComponent(q)}&per_page=10`);
+            const ac = document.getElementById('customerAutocomplete');
+
+            if (data.data.length === 0) {
+                ac.innerHTML = '<div class="ac-item" style="color:#999;">Sin resultados</div>';
+            } else {
+                let html = '';
+                data.data.forEach(c => {
+                    const tiers = { 1: 'Mostrador', 2: 'Taller', 3: 'Mayoreo' };
+                    html += `<div class="ac-item" onclick='POS.selectCustomer(${JSON.stringify(c).replace(/'/g, "&#39;")})'>
+                        <div>${c.name}</div>
+                        <div class="ac-meta">${c.rfc || ''} | ${c.phone || ''} | ${tiers[c.price_tier] || 'P1'} | Credito: ${fmt(c.credit_balance)}/${fmt(c.credit_limit)}</div>
+                    </div>`;
+                });
+                ac.innerHTML = html;
+            }
+            ac.style.display = 'block';
+        } catch (e) {
+            console.error('Customer search error:', e);
+        }
+    }
+
+    async function selectCustomer(customer) {
+        currentCustomer = customer;
+        document.getElementById('customerAutocomplete').style.display = 'none';
+        document.getElementById('customerSearchWrap').querySelector('input').style.display = 'none';
+
+        const tiers = { 1: 'P1 Mostrador', 2: 'P2 Taller', 3: 'P3 Mayoreo' };
+        document.getElementById('customerName').textContent = customer.name;
+        document.getElementById('customerTier').textContent = tiers[customer.price_tier] || 'P1';
+        document.getElementById('customerCredit').textContent =
+            `Credito: ${fmt(customer.credit_balance)} / ${fmt(customer.credit_limit)}`;
+        document.getElementById('customerSelected').style.display = '';
+
+        // Show vehicle info
+        if (customer.vehicle_info && customer.vehicle_info.length > 0) {
+            const v = customer.vehicle_info[0];
+            document.getElementById('vehicleInfo').textContent =
+                `${v.make || ''} ${v.model || ''} ${v.year || ''} ${v.plates ? '(' + v.plates + ')' : ''}`;
+            document.getElementById('vehicleBanner').classList.add('visible');
+        }
+
+        // Fetch full customer detail to get recent purchase info
+        try {
+            const detail = await api(`/pos/api/customers/${customer.id}`);
+            if (detail.recent_purchases && detail.recent_purchases.length > 0) {
+                const last = detail.recent_purchases[0];
+                const daysAgo = Math.floor((Date.now() - new Date(last.created_at).getTime()) / 86400000);
+                const daysText = daysAgo === 0 ? 'hoy' : daysAgo === 1 ? 'hace 1 dia' : `hace ${daysAgo} dias`;
+                document.getElementById('lastPurchaseInfo').textContent =
+                    `Ultima compra: ${fmt(last.total)} ${daysText}`;
+                document.getElementById('vehicleBanner').classList.add('visible');
+            }
+        } catch (e) {
+            console.warn('Could not fetch customer detail:', e);
+        }
+
+        // Re-apply prices based on customer tier
+        cart.forEach(item => {
+            // Fetch updated price for this customer tier (would need to re-query)
+            // For now, prices stay as-is (they were set at add time)
+        });
+
+        renderCart();
+    }
+
+    function clearCustomer() {
+        currentCustomer = null;
+        document.getElementById('customerSelected').style.display = 'none';
+        document.getElementById('customerSearchWrap').querySelector('input').style.display = '';
+        document.getElementById('customerSearchWrap').querySelector('input').value = '';
+        document.getElementById('vehicleBanner').classList.remove('visible');
+        renderCart();
+    }
+
+    // ─── New Customer Modal ──────────────
+    function showNewCustomerModal() {
+        document.getElementById('newCustomerModal').classList.add('active');
+        document.getElementById('ncName').focus();
+    }
+
+    function closeNewCustomerModal() {
+        document.getElementById('newCustomerModal').classList.remove('active');
+    }
+
+    async function saveNewCustomer() {
+        const name = document.getElementById('ncName').value.trim();
+        if (!name) { alert('Nombre es requerido'); return; }
+
+        const vehicle_info = [];
+        const make = document.getElementById('ncVehMake').value.trim();
+        if (make) {
+            vehicle_info.push({
+                make: make,
+                model: document.getElementById('ncVehModel').value.trim(),
+                year: document.getElementById('ncVehYear').value.trim(),
+                plates: document.getElementById('ncVehPlates').value.trim(),
+            });
+        }
+
+        const body = {
+            name: name,
+            rfc: document.getElementById('ncRfc').value.trim() || null,
+            razon_social: document.getElementById('ncRazonSocial').value.trim() || null,
+            regimen_fiscal: document.getElementById('ncRegimenFiscal').value || null,
+            uso_cfdi: document.getElementById('ncUsoCfdi').value || 'G03',
+            phone: document.getElementById('ncPhone').value.trim() || null,
+            email: document.getElementById('ncEmail').value.trim() || null,
+            price_tier: parseInt(document.getElementById('ncPriceTier').value) || 1,
+            credit_limit: parseFloat(document.getElementById('ncCreditLimit').value) || 0,
+            vehicle_info: vehicle_info.length > 0 ? vehicle_info : null,
+        };
+
+        try {
+            const result = await api('/pos/api/customers', {
+                method: 'POST',
+                body: JSON.stringify(body),
+            });
+
+            // Select the new customer
+            selectCustomer({
+                id: result.id,
+                name: body.name,
+                rfc: body.rfc,
+                phone: body.phone,
+                price_tier: body.price_tier,
+                credit_limit: body.credit_limit,
+                credit_balance: 0,
+                vehicle_info: body.vehicle_info,
+            });
+
+            closeNewCustomerModal();
+        } catch (e) {
+            alert('Error al crear cliente: ' + e.message);
+        }
+    }
+
+    // ─── Payment ─────────────────────────
+    function checkout() {
+        if (cart.length === 0) { alert('Carrito vacio'); return; }
+        if (!currentRegister) { alert('No hay caja abierta. Abra una caja primero.'); return; }
+
+        paymentMethod = 'efectivo';
+        const total = getTotal();
+
+        document.getElementById('modalTotal').textContent = fmt(total);
+        document.getElementById('cashReceived').value = '';
+        document.getElementById('changeDisplay').textContent = 'Cambio: $0.00';
+        document.getElementById('changeDisplay').className = 'change-display positive';
+        document.getElementById('paymentRef').value = '';
+
+        // Reset payment method buttons
+        document.querySelectorAll('.pm-btn').forEach(b => b.classList.remove('active'));
+        document.querySelector('.pm-btn[data-method="efectivo"]').classList.add('active');
+        document.getElementById('cashPayment').style.display = '';
+        document.getElementById('refPayment').style.display = 'none';
+        document.getElementById('mixedPayment').style.display = 'none';
+
+        document.getElementById('paymentModal').classList.add('active');
+        setTimeout(() => document.getElementById('cashReceived').focus(), 100);
+    }
+
+    function selectPaymentMethod(method, btn) {
+        paymentMethod = method;
+        document.querySelectorAll('.pm-btn').forEach(b => b.classList.remove('active'));
+        btn.classList.add('active');
+
+        document.getElementById('cashPayment').style.display = method === 'efectivo' ? '' : 'none';
+        document.getElementById('refPayment').style.display = (method === 'transferencia' || method === 'tarjeta') ? '' : 'none';
+        document.getElementById('mixedPayment').style.display = method === 'mixto' ? '' : 'none';
+
+        if (method === 'efectivo') document.getElementById('cashReceived').focus();
+        if (method === 'transferencia' || method === 'tarjeta') document.getElementById('paymentRef').focus();
+    }
+
+    function updateChange() {
+        const total = getTotal();
+        const received = parseFloat(document.getElementById('cashReceived').value) || 0;
+        const change = received - total;
+        const el = document.getElementById('changeDisplay');
+        el.textContent = `Cambio: ${fmt(Math.abs(change))}`;
+        el.className = 'change-display ' + (change >= 0 ? 'positive' : 'negative');
+    }
+
+    function updateMixedTotal() {
+        const total = getTotal();
+        let sum = 0;
+        document.querySelectorAll('.mixed-amount').forEach(input => {
+            sum += parseFloat(input.value) || 0;
+        });
+        const remaining = total - sum;
+        document.getElementById('mixedRemaining').textContent =
+            remaining > 0 ? `Faltante: ${fmt(remaining)}` : `Cubierto (${fmt(sum)})`;
+        document.getElementById('mixedRemaining').style.color = remaining > 0 ? '#c62828' : '#2e7d32';
+    }
+
+    function closePaymentModal() {
+        document.getElementById('paymentModal').classList.remove('active');
+    }
+
+    async function confirmPayment() {
+        const total = getTotal();
+        let amountPaid = 0;
+        let paymentDetails = [];
+        let reference = '';
+
+        if (paymentMethod === 'efectivo') {
+            amountPaid = parseFloat(document.getElementById('cashReceived').value) || 0;
+            if (amountPaid < total) { alert(`Monto insuficiente. Total: ${fmt(total)}`); return; }
+        } else if (paymentMethod === 'transferencia' || paymentMethod === 'tarjeta') {
+            amountPaid = total;
+            reference = document.getElementById('paymentRef').value.trim();
+        } else if (paymentMethod === 'mixto') {
+            const rows = document.querySelectorAll('.mixed-row');
+            rows.forEach(row => {
+                const method = row.querySelector('select').value;
+                const amount = parseFloat(row.querySelector('.mixed-amount').value) || 0;
+                const ref = row.querySelectorAll('input')[1]?.value || '';
+                if (amount > 0) {
+                    paymentDetails.push({ method, amount, reference: ref });
+                    amountPaid += amount;
+                }
+            });
+            if (amountPaid < total) { alert(`Monto total insuficiente. Falta: ${fmt(total - amountPaid)}`); return; }
+        }
+
+        const saleData = {
+            items: cart.map(item => ({
+                inventory_id: item.inventory_id,
+                quantity: item.quantity,
+                unit_price: item.unit_price,
+                discount_pct: item.discount_pct,
+                tax_rate: item.tax_rate,
+            })),
+            customer_id: currentCustomer ? currentCustomer.id : null,
+            payment_method: paymentMethod,
+            sale_type: 'cash',
+            register_id: currentRegister ? currentRegister.id : null,
+            amount_paid: amountPaid,
+            payment_details: paymentDetails,
+            reference: reference,
+        };
+
+        document.getElementById('btnConfirmPayment').disabled = true;
+        document.getElementById('btnConfirmPayment').textContent = 'Procesando...';
+
+        try {
+            const sale = await api('/pos/api/sales', {
+                method: 'POST',
+                body: JSON.stringify(saleData),
+            });
+
+            lastSaleId = sale.id;
+            closePaymentModal();
+            showTicket(sale);
+
+            // Clear cart
+            cart = [];
+            selectedRow = -1;
+            clearCustomer();
+            renderCart();
+
+        } catch (e) {
+            alert('Error al procesar venta: ' + e.message);
+        } finally {
+            document.getElementById('btnConfirmPayment').disabled = false;
+            document.getElementById('btnConfirmPayment').textContent = 'Confirmar Pago';
+        }
+    }
+
+    // ─── Credit Sale ─────────────────────
+    async function creditSale() {
+        if (cart.length === 0) { alert('Carrito vacio'); return; }
+        if (!currentCustomer) { alert('Seleccione un cliente para venta a credito'); return; }
+        if (!currentRegister) { alert('No hay caja abierta.'); return; }
+
+        const total = getTotal();
+        const available = (currentCustomer.credit_limit || 0) - (currentCustomer.credit_balance || 0);
+
+        if (currentCustomer.credit_limit > 0 && total > available) {
+            if (!confirm(`Credito insuficiente. Disponible: ${fmt(available)}, Total: ${fmt(total)}. Continuar de todas formas?`)) {
+                return;
+            }
+        }
+
+        const saleData = {
+            items: cart.map(item => ({
+                inventory_id: item.inventory_id,
+                quantity: item.quantity,
+                unit_price: item.unit_price,
+                discount_pct: item.discount_pct,
+                tax_rate: item.tax_rate,
+            })),
+            customer_id: currentCustomer.id,
+            payment_method: 'credito',
+            sale_type: 'credit',
+            register_id: currentRegister ? currentRegister.id : null,
+            amount_paid: 0,
+        };
+
+        try {
+            const sale = await api('/pos/api/sales', {
+                method: 'POST',
+                body: JSON.stringify(saleData),
+            });
+
+            lastSaleId = sale.id;
+            showTicket(sale);
+            cart = [];
+            selectedRow = -1;
+            clearCustomer();
+            renderCart();
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    // ─── Quotation ───────────────────────
+    async function saveQuotation() {
+        if (cart.length === 0) { alert('Carrito vacio'); return; }
+
+        const body = {
+            items: cart.map(item => ({
+                inventory_id: item.inventory_id,
+                quantity: item.quantity,
+                unit_price: item.unit_price,
+                discount_pct: item.discount_pct,
+                tax_rate: item.tax_rate,
+            })),
+            customer_id: currentCustomer ? currentCustomer.id : null,
+        };
+
+        try {
+            const result = await api('/pos/api/quotations', {
+                method: 'POST',
+                body: JSON.stringify(body),
+            });
+            alert(`Cotizacion #${result.id} guardada. Total: ${fmt(result.total)}\nValida hasta: ${result.valid_until}`);
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    // ─── Layaway ─────────────────────────
+    async function createLayaway() {
+        if (cart.length === 0) { alert('Carrito vacio'); return; }
+        if (!currentCustomer) { alert('Seleccione un cliente para apartado'); return; }
+
+        const total = getTotal();
+        const initialPayment = prompt(`Total: ${fmt(total)}\nIngrese monto del anticipo:`);
+        if (!initialPayment) return;
+
+        const amount = parseFloat(initialPayment);
+        if (isNaN(amount) || amount <= 0) { alert('Monto invalido'); return; }
+        if (amount > total) { alert('El anticipo no puede exceder el total'); return; }
+
+        const body = {
+            items: cart.map(item => ({
+                inventory_id: item.inventory_id,
+                quantity: item.quantity,
+                unit_price: item.unit_price,
+                discount_pct: item.discount_pct,
+                tax_rate: item.tax_rate,
+            })),
+            customer_id: currentCustomer.id,
+            initial_payment: amount,
+            payment_method: 'efectivo',
+            register_id: currentRegister ? currentRegister.id : null,
+        };
+
+        try {
+            const result = await api('/pos/api/layaways', {
+                method: 'POST',
+                body: JSON.stringify(body),
+            });
+            alert(
+                `Apartado #${result.id} creado.\n` +
+                `Total: ${fmt(result.total)}\n` +
+                `Anticipo: ${fmt(result.amount_paid)}\n` +
+                `Restante: ${fmt(result.remaining)}\n` +
+                `Vence: ${result.expires_at}`
+            );
+            cart = [];
+            selectedRow = -1;
+            clearCustomer();
+            renderCart();
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    // ─── Ticket ──────────────────────────
+    function showTicket(sale) {
+        const lines = [];
+        lines.push('========================================');
+        lines.push('              NEXUS POS');
+        lines.push('========================================');
+        lines.push(`Venta #${sale.id}`);
+        lines.push(`Fecha: ${new Date(sale.created_at).toLocaleString('es-MX')}`);
+        if (currentCustomer) {
+            lines.push(`Cliente: ${currentCustomer.name}`);
+            if (currentCustomer.rfc) lines.push(`RFC: ${currentCustomer.rfc}`);
+        } else {
+            lines.push('Cliente: Publico General');
+        }
+        lines.push('----------------------------------------');
+
+        (sale.items || []).forEach(item => {
+            lines.push(`${item.name}`);
+            let line = `  ${item.quantity} x ${fmt(item.unit_price)}`;
+            if (item.discount_pct > 0) line += ` (-${item.discount_pct}%)`;
+            line += `  ${fmt(item.subtotal)}`;
+            lines.push(line);
+        });
+
+        lines.push('----------------------------------------');
+        lines.push(`Subtotal:      ${fmt(sale.subtotal).padStart(12)}`);
+        if (sale.discount_total > 0) {
+            lines.push(`Descuento:    -${fmt(sale.discount_total).padStart(12)}`);
+        }
+        lines.push(`IVA:           ${fmt(sale.tax_total).padStart(12)}`);
+        lines.push('========================================');
+        lines.push(`TOTAL:         ${fmt(sale.total).padStart(12)}`);
+        lines.push('========================================');
+
+        if (sale.payment_method === 'efectivo') {
+            lines.push(`Efectivo:      ${fmt(sale.amount_paid).padStart(12)}`);
+            lines.push(`Cambio:        ${fmt(sale.change_given).padStart(12)}`);
+        } else {
+            lines.push(`Pago: ${sale.payment_method}`);
+        }
+
+        lines.push('');
+        lines.push('       Gracias por su compra!');
+        lines.push('');
+
+        document.getElementById('ticketPreview').textContent = lines.join('\n');
+        document.getElementById('ticketModal').classList.add('active');
+    }
+
+    function closeTicketModal() {
+        document.getElementById('ticketModal').classList.remove('active');
+    }
+
+    function printTicket() {
+        window.print();
+    }
+
+    // ─── Last Sale ───────────────────────
+    async function showLastSale() {
+        if (!lastSaleId) { alert('No hay venta reciente'); return; }
+        try {
+            const sale = await api(`/pos/api/sales/${lastSaleId}`);
+            showTicket(sale);
+        } catch (e) {
+            alert('Error: ' + e.message);
+        }
+    }
+
+    // ─── Drawer ──────────────────────────
+    function openDrawer() {
+        // Cash drawer open command (ESC/POS compatible)
+        // In a real implementation, this would send the command to the printer
+        alert('Comando enviado al cajon de efectivo.');
+    }
+
+    // ─── Keyboard Shortcuts ──────────────
+    function setupKeyboard() {
+        document.addEventListener('keydown', (e) => {
+            // Don't intercept when typing in inputs
+            const tag = e.target.tagName;
+            const inInput = tag === 'INPUT' || tag === 'TEXTAREA' || tag === 'SELECT';
+
+            switch (e.key) {
+                case 'F1':
+                    e.preventDefault();
+                    document.getElementById('itemSearch').focus();
+                    break;
+                case 'F2':
+                    e.preventDefault();
+                    document.getElementById('customerSearch').focus();
+                    document.getElementById('customerSearch').style.display = '';
+                    document.getElementById('customerSelected').style.display = 'none';
+                    break;
+                case 'F3':
+                    e.preventDefault();
+                    checkout();
+                    break;
+                case 'F4':
+                    e.preventDefault();
+                    saveQuotation();
+                    break;
+                case 'F5':
+                    e.preventDefault();
+                    showLastSale();
+                    break;
+                case 'F6':
+                    e.preventDefault();
+                    openDrawer();
+                    break;
+                case 'Escape':
+                    e.preventDefault();
+                    if (document.getElementById('paymentModal').classList.contains('active')) {
+                        closePaymentModal();
+                    } else if (document.getElementById('newCustomerModal').classList.contains('active')) {
+                        closeNewCustomerModal();
+                    } else if (document.getElementById('ticketModal').classList.contains('active')) {
+                        closeTicketModal();
+                    } else {
+                        hideSearchResults();
+                    }
+                    break;
+                case 'Delete':
+                    if (!inInput && selectedRow >= 0 && selectedRow < cart.length) {
+                        e.preventDefault();
+                        removeFromCart(selectedRow);
+                    }
+                    break;
+                case '+':
+                    if (!inInput && selectedRow >= 0 && selectedRow < cart.length) {
+                        e.preventDefault();
+                        cart[selectedRow].quantity++;
+                        renderCart();
+                    }
+                    break;
+                case '-':
+                    if (!inInput && selectedRow >= 0 && selectedRow < cart.length) {
+                        e.preventDefault();
+                        if (cart[selectedRow].quantity > 1) {
+                            cart[selectedRow].quantity--;
+                            renderCart();
+                        }
+                    }
+                    break;
+                case '*':
+                    if (!inInput && selectedRow >= 0 && selectedRow < cart.length) {
+                        e.preventDefault();
+                        const disc = prompt('Descuento %:', cart[selectedRow].discount_pct);
+                        if (disc !== null) {
+                            updateDiscount(selectedRow, disc);
+                        }
+                    }
+                    break;
+                case 'ArrowUp':
+                    if (!inInput && cart.length > 0) {
+                        e.preventDefault();
+                        selectedRow = Math.max(0, selectedRow - 1);
+                        renderCart();
+                    }
+                    break;
+                case 'ArrowDown':
+                    if (!inInput && cart.length > 0) {
+                        e.preventDefault();
+                        selectedRow = Math.min(cart.length - 1, selectedRow + 1);
+                        renderCart();
+                    }
+                    break;
+                case 'Enter':
+                    if (e.target.id === 'cashReceived') {
+                        e.preventDefault();
+                        confirmPayment();
+                    }
+                    break;
+            }
+        });
+    }
+
+    // ─── Public API ──────────────────────
+    init();
+
+    return {
+        addToCart, removeFromCart, selectRow,
+        updateQty, updateDiscount,
+        addFromSearch, hideSearchResults,
+        selectCustomer, clearCustomer,
+        showNewCustomerModal, closeNewCustomerModal, saveNewCustomer,
+        checkout, confirmPayment, closePaymentModal,
+        selectPaymentMethod, updateChange, updateMixedTotal,
+        creditSale, saveQuotation, createLayaway,
+        showLastSale, openDrawer,
+        showTicket, closeTicketModal, printTicket,
+    };
+})();

pos/templates/customers.html

@@ -0,0 +1,221 @@
+<!-- /home/Autopartes/pos/templates/customers.html -->
+<!DOCTYPE html>
+<html lang="es">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Clientes - Nexus POS</title>
+    <link rel="stylesheet" href="/pos/static/css/common.css">
+    <style>
+        * { margin: 0; padding: 0; box-sizing: border-box; }
+        body { font-family: var(--font-body, 'Segoe UI', system-ui, sans-serif); background: var(--color-bg, #f0f2f5); color: var(--color-text, #1a1a2e); }
+
+        .topbar { background: var(--color-primary, #1a1a2e); color: #fff; padding: 12px 24px; display: flex; align-items: center; justify-content: space-between; }
+        .topbar h1 { font-size: 18px; font-weight: 600; }
+        .topbar .nav-links a { color: #b0bec5; text-decoration: none; margin-left: 16px; font-size: 14px; }
+        .topbar .nav-links a:hover { color: #fff; }
+
+        .container { max-width: 1200px; margin: 0 auto; padding: 20px; }
+
+        .toolbar { display: flex; gap: 12px; margin-bottom: 16px; align-items: center; }
+        .toolbar input { flex: 1; padding: 10px 14px; border: 1px solid var(--color-border, #ddd); border-radius: var(--radius, 6px); font-size: 14px; }
+        .toolbar .btn { padding: 10px 20px; border: none; border-radius: var(--radius, 6px); cursor: pointer; font-size: 14px; font-weight: 500; }
+        .btn-primary { background: var(--color-primary, #1a1a2e); color: #fff; }
+        .btn-secondary { background: #e0e0e0; color: #333; }
+
+        .customers-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius, 6px); overflow: hidden; box-shadow: var(--shadow, 0 1px 3px rgba(0,0,0,0.1)); }
+        .customers-table th { background: var(--color-surface, #f8f9fa); padding: 10px 12px; text-align: left; font-size: 12px; font-weight: 600; color: #666; border-bottom: 2px solid var(--color-border, #ddd); }
+        .customers-table td { padding: 10px 12px; font-size: 13px; border-bottom: 1px solid #f0f0f0; }
+        .customers-table tr { cursor: pointer; }
+        .customers-table tr:hover { background: #f8f9fa; }
+
+        .tier-badge { display: inline-block; padding: 2px 8px; border-radius: 12px; font-size: 11px; font-weight: 600; }
+        .tier-1 { background: #e3f2fd; color: #1565c0; }
+        .tier-2 { background: #e8f5e9; color: #2e7d32; }
+        .tier-3 { background: #fff3e0; color: #e65100; }
+
+        .credit-bar { width: 80px; height: 6px; background: #e0e0e0; border-radius: 3px; display: inline-block; vertical-align: middle; margin-left: 6px; }
+        .credit-fill { height: 100%; border-radius: 3px; background: #4caf50; }
+        .credit-fill.warning { background: #ff9800; }
+        .credit-fill.danger { background: #f44336; }
+
+        .pagination { display: flex; justify-content: center; gap: 8px; margin-top: 16px; }
+        .pagination .btn { padding: 6px 12px; font-size: 13px; }
+        .pagination .btn.active { background: var(--color-primary, #1a1a2e); color: #fff; }
+
+        /* Detail panel */
+        .detail-panel { display: none; position: fixed; top: 0; right: 0; width: 480px; height: 100vh; background: #fff; box-shadow: -4px 0 20px rgba(0,0,0,0.15); z-index: 100; overflow-y: auto; }
+        .detail-panel.active { display: block; }
+        .detail-header { padding: 16px 20px; background: var(--color-primary, #1a1a2e); color: #fff; display: flex; justify-content: space-between; align-items: center; }
+        .detail-header h2 { font-size: 16px; }
+        .detail-header .btn-close { background: none; border: none; color: #fff; font-size: 24px; cursor: pointer; }
+        .detail-body { padding: 20px; }
+        .detail-section { margin-bottom: 20px; }
+        .detail-section h3 { font-size: 14px; font-weight: 600; color: #666; margin-bottom: 8px; border-bottom: 1px solid #eee; padding-bottom: 4px; }
+        .detail-field { display: flex; justify-content: space-between; padding: 4px 0; font-size: 13px; }
+        .detail-field .label { color: #999; }
+
+        .credit-summary { background: #f5f5f5; padding: 12px; border-radius: 8px; margin-bottom: 16px; }
+        .credit-summary .big-number { font-size: 24px; font-weight: 700; }
+
+        .purchases-list { max-height: 300px; overflow-y: auto; }
+        .purchase-item { padding: 8px 0; border-bottom: 1px solid #f0f0f0; font-size: 13px; display: flex; justify-content: space-between; }
+
+        .vehicle-card { background: #f5f5f5; padding: 10px 12px; border-radius: 8px; margin-bottom: 8px; font-size: 13px; }
+
+        /* Modal */
+        .modal-overlay { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); z-index: 200; align-items: center; justify-content: center; }
+        .modal-overlay.active { display: flex; }
+        .modal { background: #fff; border-radius: 12px; padding: 24px; width: 550px; max-width: 95vw; max-height: 90vh; overflow-y: auto; }
+        .modal h2 { margin-bottom: 16px; }
+        .form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
+        .form-grid .full-width { grid-column: 1 / -1; }
+        .form-field { display: flex; flex-direction: column; gap: 4px; }
+        .form-field label { font-size: 12px; color: #666; font-weight: 500; }
+        .form-field input, .form-field select { padding: 8px; border: 1px solid #ddd; border-radius: 6px; font-size: 13px; }
+        .modal-actions { display: flex; gap: 8px; margin-top: 16px; justify-content: flex-end; }
+        .modal-actions .btn { padding: 10px 20px; border: none; border-radius: 6px; cursor: pointer; font-size: 14px; }
+    </style>
+</head>
+<body>
+    <div class="topbar">
+        <h1>Clientes</h1>
+        <div class="nav-links">
+            <a href="/pos/sale">POS</a>
+            <a href="/pos/catalog">Catalogo</a>
+            <a href="/pos/inventory">Inventario</a>
+            <a href="/pos/customers">Clientes</a>
+        </div>
+    </div>
+
+    <div class="container">
+        <div class="toolbar">
+            <input type="text" id="searchInput" placeholder="Buscar por nombre, RFC, telefono..." oninput="Customers.search()">
+            <button class="btn btn-primary" onclick="Customers.showCreateModal()">+ Nuevo Cliente</button>
+        </div>
+
+        <table class="customers-table">
+            <thead>
+                <tr>
+                    <th>Nombre</th>
+                    <th>RFC</th>
+                    <th>Telefono</th>
+                    <th>Lista</th>
+                    <th>Credito</th>
+                    <th>Saldo</th>
+                </tr>
+            </thead>
+            <tbody id="customersBody"></tbody>
+        </table>
+
+        <div class="pagination" id="pagination"></div>
+    </div>
+
+    <!-- Detail Panel (slides in from right) -->
+    <div class="detail-panel" id="detailPanel">
+        <div class="detail-header">
+            <h2 id="detailName">Cliente</h2>
+            <button class="btn-close" onclick="Customers.closeDetail()">&times;</button>
+        </div>
+        <div class="detail-body">
+            <div class="detail-section">
+                <div class="credit-summary">
+                    <div>Credito disponible</div>
+                    <div class="big-number" id="detailCreditAvailable">$0.00</div>
+                    <div style="font-size: 12px; color: #666;">
+                        Limite: <span id="detailCreditLimit">$0.00</span> |
+                        Saldo: <span id="detailCreditBalance">$0.00</span>
+                    </div>
+                </div>
+            </div>
+
+            <div class="detail-section">
+                <h3>Datos Fiscales</h3>
+                <div id="detailFiscal"></div>
+            </div>
+
+            <div class="detail-section">
+                <h3>Contacto</h3>
+                <div id="detailContact"></div>
+            </div>
+
+            <div class="detail-section">
+                <h3>Vehiculos</h3>
+                <div id="detailVehicles"></div>
+            </div>
+
+            <div class="detail-section">
+                <h3>Compras Recientes</h3>
+                <div class="purchases-list" id="detailPurchases"></div>
+            </div>
+
+            <div style="display: flex; gap: 8px; margin-top: 16px;">
+                <button class="btn btn-primary" onclick="Customers.editCurrent()">Editar</button>
+                <button class="btn btn-secondary" onclick="Customers.showStatement()">Estado de Cuenta</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Create/Edit Modal -->
+    <div class="modal-overlay" id="customerModal">
+        <div class="modal">
+            <h2 id="modalTitle">Nuevo Cliente</h2>
+            <input type="hidden" id="editId">
+            <div class="form-grid">
+                <div class="form-field full-width"><label>Nombre *</label><input type="text" id="fName"></div>
+                <div class="form-field"><label>RFC</label><input type="text" id="fRfc" maxlength="13"></div>
+                <div class="form-field"><label>Razon Social</label><input type="text" id="fRazonSocial"></div>
+                <div class="form-field"><label>Regimen Fiscal</label>
+                    <select id="fRegimenFiscal">
+                        <option value="">Seleccionar...</option>
+                        <option value="601">601 - General de Ley PM</option>
+                        <option value="603">603 - PM Fines No Lucrativos</option>
+                        <option value="605">605 - Sueldos y Salarios</option>
+                        <option value="606">606 - Arrendamiento</option>
+                        <option value="612">612 - PF Actividad Empresarial</option>
+                        <option value="616">616 - Sin Obligaciones Fiscales</option>
+                        <option value="621">621 - Incorporacion Fiscal</option>
+                        <option value="625">625 - RESICO</option>
+                    </select>
+                </div>
+                <div class="form-field"><label>Uso CFDI</label>
+                    <select id="fUsoCfdi">
+                        <option value="G03">G03 - Gastos en general</option>
+                        <option value="G01">G01 - Adquisicion de mercancias</option>
+                        <option value="P01">P01 - Por definir</option>
+                    </select>
+                </div>
+                <div class="form-field"><label>Codigo Postal</label><input type="text" id="fCp" maxlength="5"></div>
+                <div class="form-field"><label>Telefono</label><input type="tel" id="fPhone"></div>
+                <div class="form-field"><label>Email</label><input type="email" id="fEmail"></div>
+                <div class="form-field full-width"><label>Direccion</label><input type="text" id="fAddress"></div>
+                <div class="form-field"><label>Lista de precio</label>
+                    <select id="fPriceTier">
+                        <option value="1">1 - Mostrador</option>
+                        <option value="2">2 - Taller</option>
+                        <option value="3">3 - Mayoreo</option>
+                    </select>
+                </div>
+                <div class="form-field"><label>Limite de credito</label><input type="number" id="fCreditLimit" value="0" min="0" step="100"></div>
+            </div>
+            <div class="modal-actions">
+                <button class="btn btn-secondary" onclick="Customers.closeModal()">Cancelar</button>
+                <button class="btn btn-primary" onclick="Customers.save()">Guardar</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Statement Modal -->
+    <div class="modal-overlay" id="statementModal">
+        <div class="modal" style="width: 650px;">
+            <h2>Estado de Cuenta: <span id="statementName"></span></h2>
+            <div id="statementContent" style="max-height: 500px; overflow-y: auto;"></div>
+            <div class="modal-actions" style="margin-top: 16px;">
+                <button class="btn btn-secondary" onclick="document.getElementById('statementModal').classList.remove('active')">Cerrar</button>
+            </div>
+        </div>
+    </div>
+
+    <script src="/pos/static/js/customers.js"></script>
+</body>
+</html>

pos/templates/pos.html

@@ -0,0 +1,403 @@
+<!-- /home/Autopartes/pos/templates/pos.html -->
+<!DOCTYPE html>
+<html lang="es">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Punto de Venta - Nexus POS</title>
+    <link rel="stylesheet" href="/pos/static/css/common.css">
+    <style>
+        * { margin: 0; padding: 0; box-sizing: border-box; }
+        body { font-family: var(--font-body, 'Segoe UI', system-ui, sans-serif); background: var(--color-bg, #f0f2f5); color: var(--color-text, #1a1a2e); height: 100vh; display: flex; flex-direction: column; overflow: hidden; }
+
+        /* Top bar */
+        .pos-topbar { background: var(--color-primary, #1a1a2e); color: #fff; padding: 8px 16px; display: flex; align-items: center; justify-content: space-between; font-size: 14px; }
+        .pos-topbar .employee-info { display: flex; align-items: center; gap: 12px; }
+        .pos-topbar .register-info { display: flex; align-items: center; gap: 8px; opacity: 0.8; }
+        .pos-topbar .register-info.no-register { color: #ff6b6b; opacity: 1; }
+        .pos-topbar .shortcuts-hint { font-size: 12px; opacity: 0.6; }
+
+        /* Main layout */
+        .pos-main { display: flex; flex: 1; overflow: hidden; }
+
+        /* Left panel: search + items */
+        .pos-left { width: 55%; display: flex; flex-direction: column; border-right: 2px solid var(--color-border, #ddd); background: #fff; }
+
+        /* Customer bar */
+        .customer-bar { padding: 8px 12px; background: var(--color-surface, #f8f9fa); border-bottom: 1px solid var(--color-border, #ddd); display: flex; gap: 8px; align-items: center; }
+        .customer-bar input { flex: 1; padding: 8px 12px; border: 1px solid var(--color-border, #ddd); border-radius: var(--radius, 6px); font-size: 14px; }
+        .customer-bar .customer-selected { background: #e8f5e9; padding: 6px 12px; border-radius: var(--radius, 6px); font-size: 13px; display: flex; align-items: center; gap: 8px; }
+        .customer-bar .customer-selected .tier-badge { font-size: 11px; padding: 2px 6px; border-radius: 3px; background: #1976d2; color: #fff; }
+        .customer-bar .customer-selected .credit-info { font-size: 11px; color: #666; }
+        .customer-bar .btn-new-customer { padding: 8px 12px; border: 1px dashed var(--color-border, #ddd); border-radius: var(--radius, 6px); background: none; cursor: pointer; font-size: 13px; white-space: nowrap; }
+        .customer-autocomplete { position: absolute; top: 100%; left: 0; right: 0; background: #fff; border: 1px solid var(--color-border, #ddd); border-radius: 0 0 var(--radius, 6px) var(--radius, 6px); box-shadow: var(--shadow, 0 4px 12px rgba(0,0,0,0.1)); z-index: 100; max-height: 200px; overflow-y: auto; }
+        .customer-autocomplete .ac-item { padding: 8px 12px; cursor: pointer; font-size: 13px; border-bottom: 1px solid #f0f0f0; }
+        .customer-autocomplete .ac-item:hover { background: #f0f2f5; }
+        .customer-autocomplete .ac-item .ac-meta { font-size: 11px; color: #999; }
+
+        /* Vehicle info banner */
+        .vehicle-banner { display: none; padding: 6px 12px; background: #fff3e0; border-bottom: 1px solid #ffe0b2; font-size: 12px; }
+        .vehicle-banner.visible { display: flex; align-items: center; gap: 8px; }
+
+        /* Search bar */
+        .search-bar { padding: 8px 12px; border-bottom: 1px solid var(--color-border, #ddd); display: flex; gap: 8px; }
+        .search-bar input { flex: 1; padding: 10px 14px; border: 2px solid var(--color-primary, #1a1a2e); border-radius: var(--radius, 6px); font-size: 15px; outline: none; }
+        .search-bar input:focus { border-color: var(--color-accent, #4361ee); box-shadow: 0 0 0 3px rgba(67,97,238,0.15); }
+
+        /* Cart items */
+        .cart-items { flex: 1; overflow-y: auto; padding: 0; }
+        .cart-items table { width: 100%; border-collapse: collapse; }
+        .cart-items thead th { position: sticky; top: 0; background: var(--color-surface, #f8f9fa); padding: 8px 10px; text-align: left; font-size: 12px; font-weight: 600; color: #666; border-bottom: 2px solid var(--color-border, #ddd); }
+        .cart-items tbody tr { border-bottom: 1px solid #f0f0f0; cursor: pointer; }
+        .cart-items tbody tr:hover { background: #f8f9fa; }
+        .cart-items tbody tr.selected { background: #e3f2fd; }
+        .cart-items td { padding: 8px 10px; font-size: 13px; }
+        .cart-items td.num { text-align: right; font-variant-numeric: tabular-nums; }
+        .cart-items td .part-name { font-weight: 500; }
+        .cart-items td .part-number { font-size: 11px; color: #999; }
+        .cart-items td .margin-info { font-size: 11px; color: #888; }
+        .cart-items td .margin-warning { color: #e53935; font-weight: 600; }
+        .cart-items .qty-input { width: 50px; text-align: center; border: 1px solid #ddd; border-radius: 4px; padding: 4px; font-size: 13px; }
+        .cart-items .discount-input { width: 55px; text-align: center; border: 1px solid #ddd; border-radius: 4px; padding: 4px; font-size: 13px; }
+        .cart-items .btn-remove { background: none; border: none; color: #e53935; cursor: pointer; font-size: 16px; padding: 2px 6px; }
+
+        .cart-empty { display: flex; align-items: center; justify-content: center; flex: 1; color: #999; font-size: 15px; }
+
+        /* Right panel: totals + actions */
+        .pos-right { width: 45%; display: flex; flex-direction: column; background: var(--color-surface, #f8f9fa); }
+
+        /* Search results (right side when searching) */
+        .search-results { flex: 1; overflow-y: auto; padding: 8px; display: none; }
+        .search-results.active { display: block; }
+        .search-result-item { padding: 10px 12px; background: #fff; border: 1px solid #eee; border-radius: var(--radius, 6px); margin-bottom: 6px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
+        .search-result-item:hover { border-color: var(--color-primary, #1a1a2e); background: #fafafa; }
+        .search-result-item .sr-name { font-weight: 500; font-size: 14px; }
+        .search-result-item .sr-pn { font-size: 12px; color: #666; }
+        .search-result-item .sr-stock { font-size: 12px; }
+        .search-result-item .sr-stock.zero { color: #e53935; }
+        .search-result-item .sr-price { font-weight: 600; font-size: 15px; }
+
+        /* Totals panel */
+        .totals-panel { flex: 1; display: flex; flex-direction: column; justify-content: flex-end; padding: 16px; }
+        .totals-panel.hidden { display: none; }
+        .totals-row { display: flex; justify-content: space-between; padding: 6px 0; font-size: 14px; }
+        .totals-row.discount { color: #e53935; }
+        .totals-row.total { font-size: 28px; font-weight: 700; padding: 12px 0; border-top: 2px solid var(--color-border, #ddd); margin-top: 8px; }
+
+        /* Global discount */
+        .global-discount { display: flex; align-items: center; gap: 8px; padding: 8px 0; border-top: 1px solid #eee; margin-top: 8px; }
+        .global-discount label { font-size: 13px; color: #666; }
+        .global-discount input { width: 60px; text-align: center; border: 1px solid #ddd; border-radius: 4px; padding: 4px; font-size: 13px; }
+
+        /* Action buttons */
+        .action-buttons { padding: 12px 16px; display: grid; grid-template-columns: 1fr 1fr; gap: 8px; border-top: 2px solid var(--color-border, #ddd); }
+        .action-buttons .btn { padding: 14px; border: none; border-radius: var(--radius, 6px); cursor: pointer; font-size: 14px; font-weight: 600; display: flex; align-items: center; justify-content: center; gap: 6px; transition: opacity 0.15s; }
+        .action-buttons .btn:hover { opacity: 0.85; }
+        .action-buttons .btn:active { transform: scale(0.98); }
+        .btn-cobrar { background: #2e7d32; color: #fff; grid-column: 1 / -1; font-size: 18px; padding: 18px; }
+        .btn-cotizacion { background: #1565c0; color: #fff; }
+        .btn-apartado { background: #e65100; color: #fff; }
+        .btn-credito { background: #6a1b9a; color: #fff; }
+        .btn-last-sale { background: #455a64; color: #fff; }
+        .btn-shortcut { font-size: 11px; opacity: 0.7; margin-left: 4px; }
+
+        /* Payment modal */
+        .modal-overlay { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); z-index: 200; align-items: center; justify-content: center; }
+        .modal-overlay.active { display: flex; }
+        .modal { background: #fff; border-radius: 12px; padding: 24px; width: 500px; max-width: 95vw; max-height: 90vh; overflow-y: auto; box-shadow: 0 20px 60px rgba(0,0,0,0.3); }
+        .modal h2 { margin-bottom: 16px; font-size: 20px; }
+        .modal .modal-total { font-size: 32px; font-weight: 700; text-align: center; padding: 12px; background: #f5f5f5; border-radius: 8px; margin-bottom: 16px; }
+        .modal .payment-methods { display: flex; gap: 8px; margin-bottom: 16px; }
+        .modal .payment-methods .pm-btn { flex: 1; padding: 12px; border: 2px solid #ddd; border-radius: 8px; background: #fff; cursor: pointer; text-align: center; font-size: 13px; font-weight: 500; }
+        .modal .payment-methods .pm-btn.active { border-color: var(--color-primary, #1a1a2e); background: #f0f4ff; }
+        .modal .payment-field { margin-bottom: 12px; }
+        .modal .payment-field label { display: block; font-size: 13px; color: #666; margin-bottom: 4px; }
+        .modal .payment-field input { width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 6px; font-size: 16px; }
+        .modal .payment-field input.amount-input { font-size: 24px; text-align: right; font-weight: 600; }
+        .modal .change-display { text-align: center; padding: 12px; font-size: 20px; font-weight: 600; border-radius: 8px; margin: 12px 0; }
+        .modal .change-display.positive { background: #e8f5e9; color: #2e7d32; }
+        .modal .change-display.negative { background: #ffebee; color: #c62828; }
+
+        /* Mixed payment rows */
+        .mixed-payments { margin-bottom: 12px; }
+        .mixed-row { display: flex; gap: 8px; margin-bottom: 8px; align-items: center; }
+        .mixed-row select { padding: 8px; border: 1px solid #ddd; border-radius: 6px; font-size: 13px; }
+        .mixed-row input { flex: 1; padding: 8px; border: 1px solid #ddd; border-radius: 6px; font-size: 14px; }
+        .mixed-row .btn-remove-row { background: none; border: none; color: #e53935; cursor: pointer; font-size: 18px; }
+        .btn-add-mixed { background: none; border: 1px dashed #999; padding: 6px 12px; border-radius: 6px; cursor: pointer; font-size: 13px; color: #666; }
+
+        .modal .modal-actions { display: flex; gap: 8px; margin-top: 16px; }
+        .modal .modal-actions .btn { flex: 1; padding: 14px; border: none; border-radius: 8px; font-size: 15px; font-weight: 600; cursor: pointer; }
+        .modal .btn-confirm-payment { background: #2e7d32; color: #fff; }
+        .modal .btn-cancel-modal { background: #eee; color: #333; }
+
+        /* New customer modal */
+        .modal .form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
+        .modal .form-grid .full-width { grid-column: 1 / -1; }
+        .modal .form-field { display: flex; flex-direction: column; gap: 4px; }
+        .modal .form-field label { font-size: 12px; color: #666; font-weight: 500; }
+        .modal .form-field input, .modal .form-field select { padding: 8px; border: 1px solid #ddd; border-radius: 6px; font-size: 13px; }
+
+        /* Ticket preview */
+        .ticket-preview { font-family: var(--font-mono, 'Courier New', monospace); font-size: 12px; white-space: pre-wrap; background: #fff; padding: 16px; border: 1px dashed #999; max-width: 300px; margin: 0 auto; line-height: 1.4; }
+
+        /* Keyboard hint bar */
+        .keyboard-bar { background: #263238; color: #b0bec5; padding: 6px 16px; display: flex; gap: 16px; font-size: 11px; }
+        .keyboard-bar .kb-key { background: #37474f; padding: 2px 6px; border-radius: 3px; color: #e0e0e0; font-weight: 600; margin-right: 4px; }
+
+        @media print {
+            body * { visibility: hidden; }
+            .ticket-preview, .ticket-preview * { visibility: visible; }
+            .ticket-preview { position: absolute; left: 0; top: 0; }
+        }
+    </style>
+</head>
+<body>
+    <!-- Top Bar -->
+    <div class="pos-topbar">
+        <div class="employee-info">
+            <span id="employeeName">Cargando...</span>
+            <span id="branchName" style="opacity: 0.7; font-size: 12px;"></span>
+        </div>
+        <div class="register-info" id="registerInfo">
+            <span>Caja: --</span>
+        </div>
+        <div class="shortcuts-hint">F1=Buscar F2=Cliente F3=Cobrar F4=Cotizacion F5=Ult.Venta</div>
+    </div>
+
+    <!-- Main Layout -->
+    <div class="pos-main">
+        <!-- Left: Search + Cart -->
+        <div class="pos-left">
+            <!-- Customer Bar -->
+            <div class="customer-bar" style="position: relative;">
+                <span style="font-size: 13px; color: #666;">Cliente:</span>
+                <div id="customerSearchWrap" style="flex: 1; position: relative;">
+                    <input type="text" id="customerSearch" placeholder="Buscar cliente por nombre, RFC, telefono... (F2)" autocomplete="off">
+                    <div class="customer-autocomplete" id="customerAutocomplete" style="display:none;"></div>
+                </div>
+                <div id="customerSelected" class="customer-selected" style="display:none;">
+                    <span id="customerName"></span>
+                    <span class="tier-badge" id="customerTier"></span>
+                    <span class="credit-info" id="customerCredit"></span>
+                    <button onclick="POS.clearCustomer()" style="background:none;border:none;cursor:pointer;color:#999;font-size:16px;" title="Quitar cliente">&times;</button>
+                </div>
+                <button class="btn-new-customer" onclick="POS.showNewCustomerModal()">+ Nuevo</button>
+            </div>
+
+            <!-- Vehicle Banner -->
+            <div class="vehicle-banner" id="vehicleBanner">
+                <span style="font-weight: 600;">Vehiculo:</span>
+                <span id="vehicleInfo"></span>
+                <span id="lastPurchaseInfo" style="margin-left: auto; font-size: 11px; color: #e65100;"></span>
+            </div>
+
+            <!-- Search Bar -->
+            <div class="search-bar">
+                <input type="text" id="itemSearch" placeholder="Buscar por # parte, nombre o codigo de barras... (F1)" autocomplete="off">
+            </div>
+
+            <!-- Cart Table -->
+            <div class="cart-items" id="cartContainer">
+                <div class="cart-empty" id="cartEmpty">
+                    <div>Carrito vacio<br><span style="font-size: 13px;">Busca productos o presiona F1</span></div>
+                </div>
+                <table id="cartTable" style="display:none;">
+                    <thead>
+                        <tr>
+                            <th style="width: 30px;">#</th>
+                            <th>Producto</th>
+                            <th style="width: 60px;">Cant</th>
+                            <th style="width: 90px;">Precio</th>
+                            <th style="width: 65px;">Desc%</th>
+                            <th style="width: 90px;" class="num">Subtotal</th>
+                            <th id="thCost" style="width: 70px; display:none;" class="num">Costo</th>
+                            <th id="thMargin" style="width: 65px; display:none;" class="num">Margen</th>
+                            <th style="width: 30px;"></th>
+                        </tr>
+                    </thead>
+                    <tbody id="cartBody"></tbody>
+                </table>
+            </div>
+        </div>
+
+        <!-- Right: Search Results / Totals + Actions -->
+        <div class="pos-right">
+            <!-- Search results (shown when searching) -->
+            <div class="search-results" id="searchResults"></div>
+
+            <!-- Totals panel -->
+            <div class="totals-panel" id="totalsPanel">
+                <div>
+                    <div class="totals-row"><span>Subtotal:</span><span id="dispSubtotal">$0.00</span></div>
+                    <div class="totals-row discount" id="discountRow" style="display:none;">
+                        <span>Descuento:</span><span id="dispDiscount">-$0.00</span>
+                    </div>
+                    <div class="totals-row"><span>IVA (16%):</span><span id="dispTax">$0.00</span></div>
+                    <div class="totals-row total"><span>TOTAL:</span><span id="dispTotal">$0.00</span></div>
+                </div>
+                <div class="global-discount">
+                    <label>Descuento global:</label>
+                    <input type="number" id="globalDiscount" value="0" min="0" max="100" step="0.5">
+                    <span>%</span>
+                </div>
+            </div>
+
+            <!-- Action Buttons -->
+            <div class="action-buttons">
+                <button class="btn btn-cobrar" onclick="POS.checkout()">
+                    Cobrar<span class="btn-shortcut">F3</span>
+                </button>
+                <button class="btn btn-cotizacion" onclick="POS.saveQuotation()">
+                    Cotizacion<span class="btn-shortcut">F4</span>
+                </button>
+                <button class="btn btn-apartado" onclick="POS.createLayaway()">
+                    Apartado
+                </button>
+                <button class="btn btn-credito" onclick="POS.creditSale()">
+                    Credito
+                </button>
+                <button class="btn btn-last-sale" onclick="POS.showLastSale()">
+                    Ult. Venta<span class="btn-shortcut">F5</span>
+                </button>
+                <button class="btn" style="background:#78909c;color:#fff;" onclick="POS.openDrawer()">
+                    Cajon<span class="btn-shortcut">F6</span>
+                </button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Keyboard hints -->
+    <div class="keyboard-bar">
+        <span><span class="kb-key">F1</span>Buscar</span>
+        <span><span class="kb-key">F2</span>Cliente</span>
+        <span><span class="kb-key">F3</span>Cobrar</span>
+        <span><span class="kb-key">F4</span>Cotizacion</span>
+        <span><span class="kb-key">F5</span>Ult.Venta</span>
+        <span><span class="kb-key">F6</span>Cajon</span>
+        <span><span class="kb-key">+/-</span>Cantidad</span>
+        <span><span class="kb-key">*</span>Descuento</span>
+        <span><span class="kb-key">Enter</span>Agregar</span>
+        <span><span class="kb-key">Del</span>Eliminar</span>
+    </div>
+
+    <!-- Payment Modal -->
+    <div class="modal-overlay" id="paymentModal">
+        <div class="modal">
+            <h2>Cobrar Venta</h2>
+            <div class="modal-total" id="modalTotal">$0.00</div>
+
+            <div class="payment-methods">
+                <button class="pm-btn active" data-method="efectivo" onclick="POS.selectPaymentMethod('efectivo', this)">Efectivo</button>
+                <button class="pm-btn" data-method="transferencia" onclick="POS.selectPaymentMethod('transferencia', this)">Transferencia</button>
+                <button class="pm-btn" data-method="tarjeta" onclick="POS.selectPaymentMethod('tarjeta', this)">Tarjeta</button>
+                <button class="pm-btn" data-method="mixto" onclick="POS.selectPaymentMethod('mixto', this)">Mixto</button>
+            </div>
+
+            <!-- Cash payment -->
+            <div id="cashPayment">
+                <div class="payment-field">
+                    <label>Monto recibido:</label>
+                    <input type="number" id="cashReceived" class="amount-input" step="0.01" min="0" oninput="POS.updateChange()">
+                </div>
+                <div class="change-display positive" id="changeDisplay">Cambio: $0.00</div>
+            </div>
+
+            <!-- Transfer/Card payment -->
+            <div id="refPayment" style="display:none;">
+                <div class="payment-field">
+                    <label>Referencia:</label>
+                    <input type="text" id="paymentRef" placeholder="Numero de referencia o autorizacion">
+                </div>
+            </div>
+
+            <!-- Mixed payment -->
+            <div id="mixedPayment" style="display:none;">
+                <div class="mixed-payments" id="mixedRows">
+                    <div class="mixed-row">
+                        <select><option value="efectivo">Efectivo</option><option value="transferencia">Transferencia</option><option value="tarjeta">Tarjeta</option></select>
+                        <input type="number" step="0.01" min="0" placeholder="Monto" class="mixed-amount" oninput="POS.updateMixedTotal()">
+                        <input type="text" placeholder="Ref." style="width: 100px;">
+                    </div>
+                    <div class="mixed-row">
+                        <select><option value="transferencia">Transferencia</option><option value="efectivo">Efectivo</option><option value="tarjeta">Tarjeta</option></select>
+                        <input type="number" step="0.01" min="0" placeholder="Monto" class="mixed-amount" oninput="POS.updateMixedTotal()">
+                        <input type="text" placeholder="Ref." style="width: 100px;">
+                    </div>
+                </div>
+                <div id="mixedRemaining" style="text-align:center; font-size: 14px; color: #666; padding: 8px 0;">Faltante: $0.00</div>
+            </div>
+
+            <div class="modal-actions">
+                <button class="btn btn-cancel-modal" onclick="POS.closePaymentModal()">Cancelar (Esc)</button>
+                <button class="btn btn-confirm-payment" id="btnConfirmPayment" onclick="POS.confirmPayment()">Confirmar Pago</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- New Customer Modal -->
+    <div class="modal-overlay" id="newCustomerModal">
+        <div class="modal">
+            <h2>Nuevo Cliente</h2>
+            <div class="form-grid">
+                <div class="form-field full-width"><label>Nombre *</label><input type="text" id="ncName"></div>
+                <div class="form-field"><label>RFC</label><input type="text" id="ncRfc" maxlength="13" placeholder="XAXX010101000"></div>
+                <div class="form-field"><label>Razon Social</label><input type="text" id="ncRazonSocial"></div>
+                <div class="form-field"><label>Regimen Fiscal</label>
+                    <select id="ncRegimenFiscal">
+                        <option value="">Seleccionar...</option>
+                        <option value="601">601 - General de Ley PM</option>
+                        <option value="603">603 - Personas Morales Fines No Lucrativos</option>
+                        <option value="605">605 - Sueldos y Salarios</option>
+                        <option value="606">606 - Arrendamiento</option>
+                        <option value="612">612 - Personas Fisicas Actividad Empresarial</option>
+                        <option value="616">616 - Sin Obligaciones Fiscales</option>
+                        <option value="621">621 - Incorporacion Fiscal</option>
+                        <option value="625">625 - RESICO</option>
+                    </select>
+                </div>
+                <div class="form-field"><label>Uso CFDI</label>
+                    <select id="ncUsoCfdi">
+                        <option value="G03">G03 - Gastos en general</option>
+                        <option value="G01">G01 - Adquisicion de mercancias</option>
+                        <option value="P01">P01 - Por definir</option>
+                    </select>
+                </div>
+                <div class="form-field"><label>Telefono</label><input type="tel" id="ncPhone"></div>
+                <div class="form-field"><label>Email</label><input type="email" id="ncEmail"></div>
+                <div class="form-field"><label>Lista de precio</label>
+                    <select id="ncPriceTier">
+                        <option value="1">Mostrador (Precio 1)</option>
+                        <option value="2">Taller (Precio 2)</option>
+                        <option value="3">Mayoreo (Precio 3)</option>
+                    </select>
+                </div>
+                <div class="form-field"><label>Limite de credito</label><input type="number" id="ncCreditLimit" value="0" min="0" step="100"></div>
+                <div class="form-field full-width"><label>Vehiculo (opcional)</label></div>
+                <div class="form-field"><label>Marca</label><input type="text" id="ncVehMake" placeholder="Nissan, Toyota..."></div>
+                <div class="form-field"><label>Modelo</label><input type="text" id="ncVehModel" placeholder="Tsuru, Corolla..."></div>
+                <div class="form-field"><label>Ano</label><input type="number" id="ncVehYear" placeholder="2020"></div>
+                <div class="form-field"><label>Placas</label><input type="text" id="ncVehPlates"></div>
+            </div>
+            <div class="modal-actions" style="margin-top: 16px;">
+                <button class="btn btn-cancel-modal" onclick="POS.closeNewCustomerModal()">Cancelar</button>
+                <button class="btn btn-confirm-payment" onclick="POS.saveNewCustomer()">Guardar Cliente</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Ticket Modal -->
+    <div class="modal-overlay" id="ticketModal">
+        <div class="modal" style="width: 380px;">
+            <h2>Venta Completada</h2>
+            <div class="ticket-preview" id="ticketPreview"></div>
+            <div class="modal-actions" style="margin-top: 16px;">
+                <button class="btn btn-cancel-modal" onclick="POS.closeTicketModal()">Cerrar</button>
+                <button class="btn btn-confirm-payment" onclick="POS.printTicket()">Imprimir</button>
+            </div>
+        </div>
+    </div>
+
+    <script src="/pos/static/js/pos.js"></script>
+</body>
+</html>