"""Service Order Engine: workshop Kanban management.

States: received -> diagnosis -> waiting_parts -> repair -> quality_check -> ready -> delivered
"""

import contextlib
from datetime import datetime

from services import inventory_engine

# Rached workshop statuses (applies to all tenants).
ORDER_STATUSES = [
    'por_revisar',
    'en_revision',
    'revisada',
    'cotizada',
    'por_autorizar',
    'autorizada',
    'autorizacion_parcial',
    'en_reparacion',
    'reparada',
    'por_entregar',
    'entregado',
    'por_enviar',
    'enviado',
    'por_facturar',
    'facturada',
    'por_recolectar',
    'cancelada',
]
TERMINAL_STATUSES = {'entregado', 'facturada', 'cancelada'}

# Allow moving from any non-terminal status to any other non-terminal status,
# plus cancellation. Terminal statuses cannot change.
VALID_TRANSITIONS = {
    status: [s for s in ORDER_STATUSES if s != status]
    for status in ORDER_STATUSES
}
for terminal in TERMINAL_STATUSES:
    VALID_TRANSITIONS[terminal] = []

# Legacy statuses (kept valid for imported/old data) cannot transition anywhere.
_LEGACY_STATUSES = {
    'received', 'diagnosis', 'waiting_parts', 'repair', 'quality_check', 'ready', 'delivered'
}
for legacy in _LEGACY_STATUSES:
    VALID_TRANSITIONS.setdefault(legacy, [])


def _generate_order_number(conn):
    """Generate DDMMYYYY-N order number (daily sequential).

    Uses a per-day advisory transaction lock to avoid duplicate order
    numbers when multiple workers create orders concurrently.
    """
    cur = conn.cursor()
    today = datetime.utcnow().strftime('%d%m%Y')
    prefix = f"{today}-"
    # Serialize order creation per day within the current transaction.
    cur.execute("SELECT pg_advisory_xact_lock(hashtext(%s))", (prefix,))
    cur.execute("""
        SELECT order_number FROM service_orders
        WHERE order_number LIKE %s
        ORDER BY order_number DESC LIMIT 1
    """, (f"{prefix}%",))
    row = cur.fetchone()
    last_num = 0
    if row and row[0]:
        with contextlib.suppress(ValueError):
            last_num = int(row[0].split('-')[-1])
    new_num = last_num + 1
    cur.close()
    return f"{prefix}{new_num}"


_VALID_DELIVERY_METHODS = {'pickup', 'delivery', 'courier'}


def _normalize_delivery(data):
    """Restrict delivery_method to allowed values and clear courier when not applicable."""
    dm = data.get('delivery_method')
    if dm not in _VALID_DELIVERY_METHODS:
        data['delivery_method'] = None
    if data.get('delivery_method') not in ('delivery', 'courier'):
        data['courier_id'] = None


def create_service_order(conn, data):
    """Create a new service order.

    data: {
        customer_id, vehicle_id, branch_id, priority,
        reception_notes, estimated_cost, estimated_completion,
        employee_id, mileage_in, fuel_level, created_by,
        delivery_method, courier_id, is_direct, requires_invoice
    }
    """
    _normalize_delivery(data)
    cur = conn.cursor()
    order_number = _generate_order_number(conn)

    cur.execute("""
        INSERT INTO service_orders
            (tenant_id, branch_id, customer_id, vehicle_id, order_number, status,
             priority, reception_notes, estimated_cost, estimated_completion,
             employee_id, mechanic_name, mileage_in, fuel_level, created_by,
             delivery_method, courier_id, is_direct, requires_invoice,
            workshop_name, customer_address, customer_phone, vehicle_description)
        VALUES (%s, %s, %s, %s, %s, 'por_revisar', %s, %s, %s, %s, %s, %s, %s, %s, %s,
                %s, %s, %s, %s, %s, %s, %s, %s)
        RETURNING id
    """, (
        data.get('tenant_id'), data.get('branch_id'), data.get('customer_id'),
        data.get('vehicle_id'), order_number,
        data.get('priority', 'normal'), data.get('reception_notes'),
        data.get('estimated_cost'), data.get('estimated_completion'),
        data.get('employee_id'), data.get('mechanic_name'),
        data.get('mileage_in'), data.get('fuel_level'), data.get('created_by'),
        data.get('delivery_method'), data.get('courier_id'),
        data.get('is_direct', False), data.get('requires_invoice', False),
        data.get('workshop_name'), data.get('customer_address'),
        data.get('customer_phone'), data.get('vehicle_description'),
    ))
    so_id = cur.fetchone()[0]

    # Log initial status
    cur.execute("""
        INSERT INTO service_order_status_history
            (service_order_id, new_status, changed_by, notes)
        VALUES (%s, 'por_revisar', %s, 'Orden creada')
    """, (so_id, data.get('created_by')))

    conn.commit()
    cur.close()
    return {'service_order_id': so_id, 'order_number': order_number}


def get_service_order(conn, so_id):
    cur = conn.cursor()
    cur.execute("""
        SELECT so.id, so.order_number, so.status, so.priority,
               so.customer_id, c.name as customer_name, c.phone as customer_phone,
               c.address as customer_address, c.price_tier as customer_price_tier,
               so.vehicle_id, fv.plate as vehicle_plate, fv.make as vehicle_make, fv.model as vehicle_model,
               so.branch_id, b.name as branch_name, b.address as branch_address, b.phone as branch_phone,
               so.reception_notes, so.diagnosis_notes, so.repair_notes,
               so.delivery_notes, so.estimated_cost, so.final_cost,
               so.estimated_completion, so.actual_completion, so.delivered_at,
               so.mileage_in, so.mileage_out, so.fuel_level,
               so.employee_id, e.name as employee_name,
               so.mechanic_name,
               so.created_by, creator.name as created_by_name,
               so.created_at, so.updated_at,
               so.delivery_method, so.courier_id, co.name as courier_name, so.is_direct,
               so.requires_invoice, so.sale_id,
               so.workshop_name, so.customer_address, so.customer_phone, so.vehicle_description
        FROM service_orders so
        LEFT JOIN customers c ON so.customer_id = c.id
        LEFT JOIN fleet_vehicles fv ON so.vehicle_id = fv.id
        LEFT JOIN employees e ON so.employee_id = e.id
        LEFT JOIN employees creator ON so.created_by = creator.id
        LEFT JOIN branches b ON so.branch_id = b.id
        LEFT JOIN couriers co ON so.courier_id = co.id
        WHERE so.id = %s AND so.is_deleted = false
    """, (so_id,))
    row = cur.fetchone()
    if not row:
        cur.close()
        return None

    so = {
        'id': row[0], 'order_number': row[1], 'status': row[2], 'priority': row[3],
        'customer_id': row[4], 'customer_name': row[5], 'customer_phone': row[6],
        'customer_address': row[7], 'customer_price_tier': row[8],
        'vehicle_id': row[9], 'vehicle_plate': row[10], 'vehicle_make': row[11], 'vehicle_model': row[12],
        'branch_id': row[13], 'branch_name': row[14], 'branch_address': row[15], 'branch_phone': row[16],
        'reception_notes': row[17], 'diagnosis_notes': row[18],
        'repair_notes': row[19], 'delivery_notes': row[20],
        'estimated_cost': float(row[21]) if row[21] else None,
        'final_cost': float(row[22]) if row[22] else None,
        'estimated_completion': str(row[23]) if row[23] else None,
        'actual_completion': str(row[24]) if row[24] else None,
        'delivered_at': str(row[25]) if row[25] else None,
        'mileage_in': row[26], 'mileage_out': row[27], 'fuel_level': row[28],
        'employee_id': row[29], 'employee_name': row[30],
        'mechanic_name': row[31],
        'created_by': row[32], 'created_by_name': row[33],
        'created_at': str(row[34]), 'updated_at': str(row[35]),
        'delivery_method': row[36], 'courier_id': row[37], 'courier_name': row[38],
        'is_direct': bool(row[39]) if row[39] is not None else False,
        'requires_invoice': bool(row[40]) if row[40] is not None else False,
        'sale_id': row[41],
        'workshop_name': row[42], 'customer_address': row[43],
        'customer_phone': row[44], 'vehicle_description': row[45],
    }

    # Items
    cur.execute("""
        SELECT id, inventory_id, part_number, name, quantity, unit_cost, unit_price, status, notes,
               mechanic_id, observations
        FROM service_order_items
        WHERE service_order_id = %s
        ORDER BY id
    """, (so_id,))
    so['items'] = []
    total_parts = 0.0
    for r in cur.fetchall():
        qty = float(r[4]) if r[4] else 0
        price = float(r[6]) if r[6] else 0
        so['items'].append({
            'id': r[0], 'inventory_id': r[1], 'part_number': r[2], 'name': r[3],
            'quantity': qty,
            'unit_cost': float(r[5]) if r[5] else None,
            'unit_price': price,
            'status': r[7], 'notes': r[8],
            'mechanic_id': r[9], 'observations': r[10],
        })
        total_parts += qty * price

    # Labor
    cur.execute("""
        SELECT id, description, hours, hourly_rate, total_cost, employee_id, status
        FROM service_order_labor
        WHERE service_order_id = %s
        ORDER BY id
    """, (so_id,))
    so['labor'] = []
    total_labor = 0.0
    for r in cur.fetchall():
        total = float(r[4]) if r[4] else 0
        so['labor'].append({
            'id': r[0], 'description': r[1],
            'hours': float(r[2]) if r[2] else 0,
            'hourly_rate': float(r[3]) if r[3] else 0,
            'total_cost': total,
            'employee_id': r[5], 'status': r[6],
        })
        total_labor += total

    so['total_parts'] = round(total_parts, 2)
    so['total_labor'] = round(total_labor, 2)
    so['total'] = round(total_parts + total_labor, 2)

    # Status history
    cur.execute("""
        SELECT h.id, h.old_status, h.new_status, h.changed_by, e.name as changed_by_name,
               h.notes, h.created_at
        FROM service_order_status_history h
        LEFT JOIN employees e ON h.changed_by = e.id
        WHERE h.service_order_id = %s
        ORDER BY h.created_at
    """, (so_id,))
    so['status_history'] = []
    for r in cur.fetchall():
        so['status_history'].append({
            'id': r[0], 'old_status': r[1], 'new_status': r[2],
            'changed_by': r[3], 'changed_by_name': r[4],
            'notes': r[5], 'created_at': str(r[6]),
        })

    cur.close()
    return so


def list_service_orders(conn, status=None, branch_id=None, customer_id=None,
                        priority=None, employee_id=None, delivery_method=None,
                        is_direct=None, q=None, page=1, per_page=50):
    cur = conn.cursor()
    where_clauses = []
    params = []

    if status:
        where_clauses.append("so.status = %s")
        params.append(status)
    if branch_id:
        where_clauses.append("so.branch_id = %s")
        params.append(branch_id)
    if customer_id:
        where_clauses.append("so.customer_id = %s")
        params.append(customer_id)
    if priority:
        where_clauses.append("so.priority = %s")
        params.append(priority)
    if employee_id:
        where_clauses.append("so.employee_id = %s")
        params.append(employee_id)
    if delivery_method:
        where_clauses.append("so.delivery_method = %s")
        params.append(delivery_method)
    if is_direct is not None:
        where_clauses.append("so.is_direct = %s")
        params.append(is_direct)
    if q:
        where_clauses.append(
            "(so.order_number ILIKE %s OR c.name ILIKE %s OR fv.plate ILIKE %s OR "
            "so.workshop_name ILIKE %s OR so.vehicle_description ILIKE %s)"
        )
        params.extend([f'%{q}%', f'%{q}%', f'%{q}%', f'%{q}%', f'%{q}%'])

    where_clauses.append("so.is_deleted = false")
    where = " AND ".join(where_clauses)

    cur.execute(f"""
        SELECT count(*) FROM service_orders so
        LEFT JOIN customers c ON so.customer_id = c.id
        LEFT JOIN fleet_vehicles fv ON so.vehicle_id = fv.id
        WHERE {where}
    """, params)
    total = cur.fetchone()[0]

    cur.execute(f"""
        SELECT so.id, so.order_number, so.status, so.priority,
               so.customer_id, c.name as customer_name,
               so.vehicle_id, fv.plate as vehicle_plate, fv.make as vehicle_make, fv.model as vehicle_model,
               so.branch_id, b.name as branch_name,
               so.estimated_cost, so.final_cost,
               so.delivery_method, co.name as courier_name, so.is_direct,
               so.requires_invoice, so.sale_id, so.created_at,
               creator.name as created_by_name,
               so.employee_id, mech.name as employee_name,
               so.mechanic_name,
               so.workshop_name, so.vehicle_description
        FROM service_orders so
        LEFT JOIN customers c ON so.customer_id = c.id
        LEFT JOIN fleet_vehicles fv ON so.vehicle_id = fv.id
        LEFT JOIN branches b ON so.branch_id = b.id
        LEFT JOIN couriers co ON so.courier_id = co.id
        LEFT JOIN employees creator ON so.created_by = creator.id
        LEFT JOIN employees mech ON so.employee_id = mech.id
        WHERE {where}
        ORDER BY
            CASE so.priority
                WHEN 'urgent' THEN 1
                WHEN 'high' THEN 2
                WHEN 'normal' THEN 3
                WHEN 'low' THEN 4
            END,
            so.created_at DESC
        LIMIT %s OFFSET %s
    """, params + [per_page, (page - 1) * per_page])

    orders = []
    for r in cur.fetchall():
        estimated = float(r[12]) if r[12] else 0
        final = float(r[13]) if r[13] else None
        orders.append({
            'id': r[0], 'order_number': r[1], 'status': r[2], 'priority': r[3],
            'customer_id': r[4], 'customer_name': r[5],
            'vehicle_id': r[6], 'vehicle_plate': r[7], 'vehicle_make': r[8], 'vehicle_model': r[9],
            'branch_id': r[10], 'branch_name': r[11],
            'estimated_cost': estimated,
            'final_cost': final,
            'delivery_method': r[14], 'courier_name': r[15],
            'is_direct': bool(r[16]) if r[16] is not None else False,
            'requires_invoice': bool(r[17]) if r[17] is not None else False,
            'sale_id': r[18], 'created_at': str(r[19]),
            'created_by_name': r[20],
            'employee_id': r[21], 'employee_name': r[22],
            'mechanic_name': r[23],
            'workshop_name': r[24], 'vehicle_description': r[25],
            'total': round(final or estimated, 2),
            'paid': 0.0,  # to be computed if needed
        })

    cur.close()
    total_pages = (total + per_page - 1) // per_page
    return {
        'data': orders,
        'pagination': {'page': page, 'per_page': per_page, 'total': total, 'total_pages': total_pages}
    }


def update_status(conn, so_id, new_status, changed_by=None, notes=None):
    """Update service order status with validation."""
    cur = conn.cursor()
    cur.execute("SELECT status FROM service_orders WHERE id = %s AND is_deleted = false", (so_id,))
    row = cur.fetchone()
    if not row:
        cur.close()
        raise ValueError("Service order not found")

    old_status = row[0]
    if new_status not in VALID_TRANSITIONS.get(old_status, []):
        cur.close()
        raise ValueError(f"Invalid transition: {old_status} -> {new_status}")

    # Update status
    extra_sets = []
    extra_vals = []
    if new_status == 'reparada':
        extra_sets.append("actual_completion = NOW()")
    if new_status == 'entregado':
        extra_sets.append("delivered_at = NOW()")
        extra_sets.append("delivered_by = %s")
        extra_vals.append(changed_by)

    set_clause = ", ".join(["status = %s"] + extra_sets)
    cur.execute(f"""
        UPDATE service_orders
        SET {set_clause}
        WHERE id = %s
    """, [new_status] + extra_vals + [so_id])

    # Log history
    cur.execute("""
        INSERT INTO service_order_status_history
            (service_order_id, old_status, new_status, changed_by, notes)
        VALUES (%s, %s, %s, %s, %s)
    """, (so_id, old_status, new_status, changed_by, notes))

    conn.commit()
    cur.close()
    return {'old_status': old_status, 'new_status': new_status}


def add_item(conn, so_id, item_data):
    """Add a part/item to the service order."""
    cur = conn.cursor()
    cur.execute("""
        INSERT INTO service_order_items
            (service_order_id, inventory_id, part_number, name, quantity, unit_cost, unit_price, status, notes,
             mechanic_id, observations)
        VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
        RETURNING id
    """, (
        so_id, item_data.get('inventory_id'), item_data.get('part_number'),
        item_data.get('name'), item_data.get('quantity', 1),
        item_data.get('unit_cost'), item_data.get('unit_price'),
        item_data.get('status', 'pending'), item_data.get('notes'),
        item_data.get('mechanic_id'), item_data.get('observations'),
    ))
    item_id = cur.fetchone()[0]
    conn.commit()
    cur.close()
    return item_id


def update_item(conn, item_id, data):
    cur = conn.cursor()
    allowed = ['part_number', 'name', 'quantity', 'unit_cost', 'unit_price', 'status', 'notes', 'mechanic_id', 'observations']
    sets = []
    vals = []
    for field in allowed:
        if field in data:
            sets.append(f"{field} = %s")
            vals.append(data[field])
    if not sets:
        cur.close()
        return False
    vals.append(item_id)
    cur.execute(f"UPDATE service_order_items SET {', '.join(sets)} WHERE id = %s", vals)
    conn.commit()
    cur.close()
    return True


def remove_item(conn, item_id):
    cur = conn.cursor()
    cur.execute("DELETE FROM service_order_items WHERE id = %s", (item_id,))
    conn.commit()
    cur.close()
    return True


def add_labor(conn, so_id, labor_data):
    cur = conn.cursor()
    total_cost = labor_data.get('hours', 0) * labor_data.get('hourly_rate', 0)
    cur.execute("""
        INSERT INTO service_order_labor
            (service_order_id, description, hours, hourly_rate, total_cost, employee_id, status)
        VALUES (%s, %s, %s, %s, %s, %s, %s)
        RETURNING id
    """, (
        so_id, labor_data['description'], labor_data.get('hours', 0),
        labor_data.get('hourly_rate', 0), total_cost,
        labor_data.get('employee_id'), labor_data.get('status', 'pending'),
    ))
    labor_id = cur.fetchone()[0]
    conn.commit()
    cur.close()
    return labor_id


def update_labor(conn, labor_id, data):
    cur = conn.cursor()
    allowed = ['description', 'hours', 'hourly_rate', 'employee_id', 'status']
    sets = []
    vals = []
    for field in allowed:
        if field in data:
            sets.append(f"{field} = %s")
            vals.append(data[field])
    if not sets:
        cur.close()
        return False

    # Recalculate total_cost if hours or rate changed
    cur.execute("SELECT hours, hourly_rate FROM service_order_labor WHERE id = %s", (labor_id,))
    row = cur.fetchone()
    hours = data.get('hours', row[0]) if row else data.get('hours', 0)
    rate = data.get('hourly_rate', row[1]) if row else data.get('hourly_rate', 0)
    sets.append("total_cost = %s")
    vals.append((hours or 0) * (rate or 0))

    vals.append(labor_id)
    cur.execute(f"UPDATE service_order_labor SET {', '.join(sets)} WHERE id = %s", vals)
    conn.commit()
    cur.close()
    return True


def remove_labor(conn, labor_id):
    cur = conn.cursor()
    cur.execute("DELETE FROM service_order_labor WHERE id = %s", (labor_id,))
    conn.commit()
    cur.close()
    return True


def update_service_order(conn, so_id, data):
    """Update general service order fields."""
    _normalize_delivery(data)
    cur = conn.cursor()
    allowed = ['customer_id', 'vehicle_id', 'branch_id', 'priority',
               'reception_notes', 'diagnosis_notes', 'repair_notes',
               'delivery_notes', 'estimated_cost', 'estimated_completion',
               'employee_id', 'mechanic_name', 'mileage_in', 'mileage_out', 'fuel_level', 'final_cost',
               'delivery_method', 'courier_id', 'is_direct', 'requires_invoice',
               'workshop_name', 'customer_address', 'customer_phone', 'vehicle_description']
    sets = []
    vals = []
    for field in allowed:
        if field in data:
            sets.append(f"{field} = %s")
            vals.append(data[field])
    if not sets:
        cur.close()
        return False
    vals.append(so_id)
    cur.execute(f"UPDATE service_orders SET {', '.join(sets)} WHERE id = %s", vals)
    conn.commit()
    cur.close()
    return True


def get_kanban_summary(conn, branch_id=None):
    """Get counts per status for Kanban board."""
    cur = conn.cursor()
    params = []
    branch_filter = ""
    if branch_id:
        branch_filter = "AND branch_id = %s"
        params.append(branch_id)

    cur.execute(f"""
        SELECT status, COUNT(*) as cnt
        FROM service_orders
        WHERE status != 'cancelled' AND is_deleted = false {branch_filter}
        GROUP BY status
    """, params)

    summary = {status: 0 for status in ORDER_STATUSES if status != 'cancelada'}
    for r in cur.fetchall():
        summary[r[0]] = r[1]

    # Overdue orders (estimated_completion passed and not delivered/invoiced)
    cur.execute(f"""
        SELECT count(*) FROM service_orders
        WHERE estimated_completion < NOW()
          AND status NOT IN ('entregado', 'facturada', 'cancelada')
          AND is_deleted = false
          {branch_filter}
    """, params)
    overdue = cur.fetchone()[0]

    cur.close()
    summary['overdue'] = overdue
    return summary


# ─── Workshop inventory integration ─────────────────────────────────────────


def reserve_item(conn, so_item_id, branch_id, employee_id=None):
    """Reserve inventory for a service order item.

    Records a negative SO_RESERVE operation and updates reserved_quantity.
    Raises ValueError if stock is insufficient.
    """
    cur = conn.cursor()
    cur.execute(
        """
        SELECT soi.service_order_id, soi.inventory_id, soi.quantity, soi.status,
               so.order_number, so.branch_id
        FROM service_order_items soi
        JOIN service_orders so ON so.id = soi.service_order_id
        WHERE soi.id = %s
    """,
        (so_item_id,),
    )
    row = cur.fetchone()
    if not row:
        cur.close()
        raise ValueError("Service order item not found")

    so_id, inventory_id, quantity, status, order_number, branch_id = row
    if status == "cancelled":
        cur.close()
        raise ValueError("Cannot reserve a cancelled item")
    if not inventory_id:
        cur.close()
        raise ValueError("Item has no inventory linked")

    qty = int(quantity)
    available = inventory_engine.get_stock(conn, inventory_id, branch_id)
    if available < qty:
        cur.close()
        raise ValueError(f"Insufficient stock. Available: {available}, requested: {qty}")

    inventory_engine.record_operation(
        conn,
        inventory_id,
        branch_id,
        "SO_RESERVE",
        -qty,
        reference_id=so_id,
        reference_type="service_order_item",
        notes=f"Reserva orden {order_number}",
        employee_id=employee_id,
    )

    cur.execute(
        "UPDATE service_order_items SET reserved_quantity = %s WHERE id = %s",
        (qty, so_item_id),
    )
    conn.commit()
    cur.close()
    return {"reserved": qty}


def release_item(conn, so_item_id, employee_id=None):
    """Release a previous reservation for a service order item.

    Records a positive SO_RELEASE operation and resets reserved_quantity.
    """
    cur = conn.cursor()
    cur.execute(
        """
        SELECT soi.service_order_id, soi.inventory_id, soi.reserved_quantity,
               so.branch_id, so.order_number
        FROM service_order_items soi
        JOIN service_orders so ON so.id = soi.service_order_id
        WHERE soi.id = %s
    """,
        (so_item_id,),
    )
    row = cur.fetchone()
    if not row:
        cur.close()
        raise ValueError("Service order item not found")

    so_id, inventory_id, reserved_qty, branch_id, order_number = row
    if not inventory_id or not reserved_qty:
        cur.close()
        return {"released": 0}

    qty = int(reserved_qty)
    inventory_engine.record_operation(
        conn,
        inventory_id,
        branch_id,
        "SO_RELEASE",
        qty,
        reference_id=so_id,
        reference_type="service_order_item",
        notes=f"Liberacion reserva orden {order_number}",
        employee_id=employee_id,
    )

    cur.execute(
        "UPDATE service_order_items SET reserved_quantity = 0 WHERE id = %s",
        (so_item_id,),
    )
    conn.commit()
    cur.close()
    return {"released": qty}


def _consume_item_inventory(conn, so_item, sale_id, order_number, branch_id, employee_id=None):
    """Release reservation and record final SALE for a service order item."""
    inventory_id = so_item.get("inventory_id")
    reserved_qty = so_item.get("reserved_quantity", 0)
    qty = int(so_item.get("quantity", 0))
    if not inventory_id or qty <= 0:
        return

    if reserved_qty:
        inventory_engine.record_operation(
            conn,
            inventory_id,
            branch_id,
            "SO_RELEASE",
            int(reserved_qty),
            reference_id=so_item.get("service_order_id"),
            reference_type="service_order",
            notes=f"Liberacion para venta orden {order_number}",
            employee_id=employee_id,
        )

    inventory_engine.record_operation(
        conn,
        inventory_id,
        branch_id,
        "SALE",
        -qty,
        reference_id=sale_id,
        reference_type="sale",
        notes=f"Venta desde orden {order_number}",
        employee_id=employee_id,
    )


def convert_to_sale(conn, so_id, sale_data, employee_id=None):
    """Convert a service order into a POS sale.

    sale_data keys:
        payment_method: 'efectivo' | 'transferencia' | 'tarjeta' | 'mixto'
        sale_type: 'cash' | 'credit' | 'mixed'
        register_id: int (optional)
        amount_paid: float (optional)
        payment_details: list (optional)
        notes: str (optional)

    Returns dict with sale_id, total, items_count.
    """
    cur = conn.cursor()
    so = get_service_order(conn, so_id)
    if not so:
        cur.close()
        raise ValueError("Service order not found")
    if so["status"] == "cancelled":
        cur.close()
        raise ValueError("Cannot convert a cancelled service order")
    if so.get("sale_id"):
        cur.close()
        raise ValueError("Service order already converted to sale")

    branch_id = so["branch_id"]
    customer_id = so["customer_id"]

    # Build sale items from SO parts and labor
    sale_items = []
    for item in so.get("items", []):
        if item.get("status") == "cancelled":
            continue
        qty = int(item.get("quantity", 1))
        unit_price = float(item.get("unit_price") or 0)
        unit_cost = float(item.get("unit_cost") or 0)
        sale_items.append(
            {
                "inventory_id": item.get("inventory_id"),
                "part_number": item.get("part_number") or "PART",
                "name": item.get("name") or "Refaccion",
                "quantity": qty,
                "unit_price": unit_price,
                "unit_cost": unit_cost,
                "tax_rate": 0.16,
            }
        )

    for labor in so.get("labor", []):
        if labor.get("status") == "cancelled":
            continue
        sale_items.append(
            {
                "inventory_id": None,
                "part_number": "SERV",
                "name": labor.get("description") or "Mano de obra",
                "quantity": 1,
                "unit_price": float(labor.get("total_cost") or 0),
                "unit_cost": 0,
                "tax_rate": 0.16,
            }
        )

    if not sale_items:
        cur.close()
        raise ValueError("No items or labor to invoice")

    # Calculate totals
    subtotal = 0.0
    tax_total = 0.0
    for item in sale_items:
        item_subtotal = item["quantity"] * item["unit_price"]
        item_tax = item_subtotal * item["tax_rate"]
        item["subtotal"] = item_subtotal
        item["tax_amount"] = item_tax
        subtotal += item_subtotal
        tax_total += item_tax

    total = subtotal + tax_total

    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", total if sale_type == "cash" else 0))
    change_given = max(amount_paid - total, 0) if sale_type == "cash" and payment_method == "efectivo" else 0
    notes = sale_data.get("notes") or f"Orden de servicio {so['order_number']}"

    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")

    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, notes)
        VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, 'completed', %s)
        RETURNING id, created_at
    """,
        (
            branch_id,
            customer_id,
            employee_id,
            register_id,
            sale_type,
            payment_method,
            subtotal,
            0,
            tax_total,
            total,
            amount_paid,
            change_given,
            metodo_pago_sat,
            forma_pago_sat,
            notes,
        ),
    )
    sale_id, _created_at = cur.fetchone()

    # Insert sale_items
    for item in sale_items:
        cur.execute(
            """
            INSERT INTO sale_items
                (sale_id, inventory_id, part_number, name, quantity,
                 unit_price, unit_cost, tax_rate, tax_amount, subtotal)
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
        """,
            (
                sale_id,
                item["inventory_id"],
                item["part_number"],
                item["name"],
                item["quantity"],
                item["unit_price"],
                item["unit_cost"],
                item["tax_rate"],
                item["tax_amount"],
                item["subtotal"],
            ),
        )

    # Consume inventory for parts
    for item in so.get("items", []):
        if item.get("status") == "cancelled":
            continue
        _consume_item_inventory(
            conn, item, sale_id, so["order_number"], branch_id, employee_id
        )

    # Link order to sale
    cur.execute("UPDATE service_orders SET sale_id = %s WHERE id = %s", (sale_id, so_id))

    conn.commit()
    cur.close()
    return {"sale_id": sale_id, "total": total, "items_count": len(sale_items)}


def convert_to_remission(conn, so_id, sale_data, employee_id=None):
    """Convert a service order into a counter remission note (pending payment).

    sale_data keys:
        register_id: int (optional)
        notes: str (optional)

    Returns dict with sale_id, total, items_count.
    """
    cur = conn.cursor()
    so = get_service_order(conn, so_id)
    if not so:
        cur.close()
        raise ValueError("Service order not found")
    if so["status"] == "cancelled":
        cur.close()
        raise ValueError("Cannot convert a cancelled service order")
    if so.get("sale_id"):
        cur.close()
        raise ValueError("Service order already converted")

    branch_id = so["branch_id"]
    customer_id = so["customer_id"]

    # Build sale items from SO parts and labor
    sale_items = []
    for item in so.get("items", []):
        if item.get("status") == "cancelled":
            continue
        qty = int(item.get("quantity", 1))
        unit_price = float(item.get("unit_price") or 0)
        unit_cost = float(item.get("unit_cost") or 0)
        sale_items.append({
            "inventory_id": item.get("inventory_id"),
            "part_number": item.get("part_number") or "PART",
            "name": item.get("name") or "Refaccion",
            "quantity": qty,
            "unit_price": unit_price,
            "unit_cost": unit_cost,
            "tax_rate": 0.16,
        })

    for labor in so.get("labor", []):
        if labor.get("status") == "cancelled":
            continue
        sale_items.append({
            "inventory_id": None,
            "part_number": "SERV",
            "name": labor.get("description") or "Mano de obra",
            "quantity": 1,
            "unit_price": float(labor.get("total_cost") or 0),
            "unit_cost": 0,
            "tax_rate": 0.16,
        })

    if not sale_items:
        cur.close()
        raise ValueError("No items or labor to invoice")

    subtotal = 0.0
    tax_total = 0.0
    for item in sale_items:
        item_subtotal = item["quantity"] * item["unit_price"]
        item_tax = item_subtotal * item["tax_rate"]
        item["subtotal"] = item_subtotal
        item["tax_amount"] = item_tax
        subtotal += item_subtotal
        tax_total += item_tax

    total = subtotal + tax_total
    register_id = sale_data.get("register_id")
    notes = sale_data.get("notes") or f"Nota de remision desde orden {so['order_number']}"

    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, notes)
        VALUES (%s, %s, %s, %s, 'counter_remission', 'remission', %s, %s, %s, %s, %s, %s, 'PPD', '99', 'pending_payment', %s)
        RETURNING id, created_at
        """,
        (
            branch_id,
            customer_id,
            employee_id,
            register_id,
            subtotal,
            0,
            tax_total,
            total,
            0,
            0,
            notes,
        ),
    )
    sale_id, _created_at = cur.fetchone()

    for item in sale_items:
        cur.execute(
            """
            INSERT INTO sale_items
                (sale_id, inventory_id, part_number, name, quantity,
                 unit_price, unit_cost, tax_rate, tax_amount, subtotal)
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
            """,
            (
                sale_id,
                item["inventory_id"],
                item["part_number"],
                item["name"],
                item["quantity"],
                item["unit_price"],
                item["unit_cost"],
                item["tax_rate"],
                item["tax_amount"],
                item["subtotal"],
            ),
        )

    # Reserve inventory for parts
    for item in so.get("items", []):
        if item.get("status") == "cancelled":
            continue
        inventory_id = item.get("inventory_id")
        qty = int(item.get("quantity", 0))
        if inventory_id and qty > 0:
            inventory_engine.record_reservation(
                conn,
                inventory_id,
                branch_id,
                qty,
                sale_id=sale_id,
                cost_at_time=float(item.get("unit_cost") or 0),
                notes=f"Reserva nota de remision orden {so['order_number']}"
            )

    # Link order to sale (the remission note)
    cur.execute("UPDATE service_orders SET sale_id = %s WHERE id = %s", (sale_id, so_id))

    conn.commit()
    cur.close()
    return {"sale_id": sale_id, "total": total, "items_count": len(sale_items)}


def assign_mechanic(conn, so_id, employee_id):
    """Assign a mechanic/technician to a service order."""
    cur = conn.cursor()
    cur.execute("SELECT id FROM service_orders WHERE id = %s AND is_deleted = false", (so_id,))
    if not cur.fetchone():
        cur.close()
        raise ValueError("Service order not found")

    cur.execute(
        "UPDATE service_orders SET employee_id = %s WHERE id = %s",
        (employee_id, so_id),
    )
    conn.commit()
    cur.close()
    return {"employee_id": employee_id}


def delete_service_order(conn, so_id):
    """Soft-delete a service order."""
    cur = conn.cursor()
    cur.execute(
        "UPDATE service_orders SET is_deleted = true WHERE id = %s AND is_deleted = false",
        (so_id,),
    )
    deleted = cur.rowcount
    conn.commit()
    cur.close()
    if deleted == 0:
        raise ValueError("Service order not found")
    return {"deleted": True}


# ─── Service catalog (reusable labor concepts) ───────────────────────────────


def list_service_catalog(conn, active_only=True):
    """List reusable labor/service concepts."""
    cur = conn.cursor()
    where = "WHERE is_active = true" if active_only else ""
    cur.execute(
        f"""
        SELECT id, tenant_id, name, description, suggested_hours, suggested_rate,
               is_active, created_at, updated_at
        FROM service_catalog
        {where}
        ORDER BY name
    """
    )
    items = []
    for r in cur.fetchall():
        items.append(
            {
                "id": r[0],
                "tenant_id": r[1],
                "name": r[2],
                "description": r[3],
                "suggested_hours": float(r[4]) if r[4] else 0,
                "suggested_rate": float(r[5]) if r[5] else 0,
                "is_active": r[6],
                "created_at": str(r[7]) if r[7] else None,
                "updated_at": str(r[8]) if r[8] else None,
            }
        )
    cur.close()
    return items


def create_service_catalog_item(conn, tenant_id, data):
    """Create a reusable labor concept."""
    cur = conn.cursor()
    cur.execute(
        """
        INSERT INTO service_catalog
            (tenant_id, name, description, suggested_hours, suggested_rate, is_active)
        VALUES (%s, %s, %s, %s, %s, %s)
        RETURNING id
    """,
        (
            tenant_id,
            data.get("name"),
            data.get("description"),
            data.get("suggested_hours", 0),
            data.get("suggested_rate", 0),
            data.get("is_active", True),
        ),
    )
    item_id = cur.fetchone()[0]
    conn.commit()
    cur.close()
    return {"id": item_id}


def update_service_catalog_item(conn, item_id, data):
    """Update a reusable labor concept."""
    cur = conn.cursor()
    allowed = ["name", "description", "suggested_hours", "suggested_rate", "is_active"]
    sets = []
    vals = []
    for field in allowed:
        if field in data:
            sets.append(f"{field} = %s")
            vals.append(data[field])
    if not sets:
        cur.close()
        return False
    vals.append(item_id)
    cur.execute(f"UPDATE service_catalog SET {', '.join(sets)} WHERE id = %s", vals)
    conn.commit()
    cur.close()
    return True


def delete_service_catalog_item(conn, item_id):
    """Soft-delete a reusable labor concept by setting is_active = false."""
    cur = conn.cursor()
    cur.execute(
        "UPDATE service_catalog SET is_active = false WHERE id = %s", (item_id,)
    )
    conn.commit()
    cur.close()
    return True