Add allow_negative_stock toggle for sales, remissions, quotes, layaways and service orders

pos/blueprints/config_bp.py

@@ -1133,17 +1133,17 @@ def update_counter_remission_config():
 @config_bp.route('/sales-settings', methods=['GET'])
 @require_auth('pos.view')
 def get_sales_settings():
-    """Get sales-related settings (zero-price sales, etc.)."""
+    """Get sales-related settings (zero-price sales, negative stock)."""
     conn = get_tenant_conn(g.tenant_id)
     cur = conn.cursor()
-    cur.execute("SELECT value FROM tenant_config WHERE key = 'allow_zero_price_sales'")
-    row = cur.fetchone()
+    cur.execute("SELECT key, value FROM tenant_config WHERE key IN ('allow_zero_price_sales', 'allow_negative_stock')")
+    rows = {k: v for k, v in cur.fetchall()}
     cur.close(); conn.close()
-    # Default to true to avoid breaking existing tenants that sell at $0.
-    allow = True
-    if row:
-        allow = str(row[0]).lower() in ('true', '1', 'yes')
-    return jsonify({'allow_zero_price_sales': allow})
+    # Default allow_zero_price_sales to true to avoid breaking existing tenants.
+    allow = str(rows.get('allow_zero_price_sales', 'true')).lower() in ('true', '1', 'yes')
+    # Default allow_negative_stock to false (safer).
+    neg = str(rows.get('allow_negative_stock', 'false')).lower() in ('true', '1', 'yes')
+    return jsonify({'allow_zero_price_sales': allow, 'allow_negative_stock': neg})
 
 
 @config_bp.route('/sales-settings', methods=['PUT'])
@@ -1152,15 +1152,20 @@ def update_sales_settings():
     """Update sales-related settings."""
     data = request.get_json() or {}
     allow = 'true' if data.get('allow_zero_price_sales') else 'false'
+    neg = 'true' if data.get('allow_negative_stock') else 'false'
     conn = get_tenant_conn(g.tenant_id)
     cur = conn.cursor()
     cur.execute("""
         INSERT INTO tenant_config (key, value) VALUES (%s, %s)
         ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value
     """, ('allow_zero_price_sales', allow))
+    cur.execute("""
+        INSERT INTO tenant_config (key, value) VALUES (%s, %s)
+        ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value
+    """, ('allow_negative_stock', neg))
     conn.commit()
     cur.close(); conn.close()
-    return jsonify({'allow_zero_price_sales': allow == 'true'})
+    return jsonify({'allow_zero_price_sales': allow == 'true', 'allow_negative_stock': neg == 'true'})
 
 
 @config_bp.route('/onboarding-status', methods=['GET'])

pos/blueprints/pos_bp.py

@@ -55,6 +55,21 @@ def _validate_zero_price(conn, items):
             raise ValueError(f"No está permitido vender artículos en $0 ({name})")
 
 
+def _validate_stock_availability(conn, items, branch_id):
+    """Raise ValueError if stock is insufficient and the tenant forbids negative stock."""
+    if _tenant_allows_negative_stock(conn):
+        return
+    for item in items:
+        inv_id = item.get('inventory_id')
+        qty = int(item.get('quantity', 1) or 1)
+        if not inv_id:
+            continue
+        available = get_stock(conn, inv_id, branch_id)
+        if available < qty:
+            name = item.get('name') or item.get('part_number') or inv_id
+            raise ValueError(f'Sin stock suficiente para {name}. Disponible: {available}, solicitado: {qty}')
+
+
 def _enrich_items(cur, items, customer_id=None):
     """Look up inventory data for items that lack unit_price/tax_rate.
 
@@ -136,22 +151,10 @@ def create_sale():
     data = request.get_json() or {}
     conn = get_tenant_conn(g.tenant_id)
 
-    # Verify stock availability per item for the active branch
-    # (skipped for tenants configured to allow negative stock / oversell)
     branch_id = data.get('branch_id', g.branch_id)
-    if not _tenant_allows_negative_stock(conn):
-        for item in data.get('items', []):
-            inv_id = item.get('inventory_id')
-            qty = int(item.get('quantity', 1))
-            if inv_id:
-                available = get_stock(conn, inv_id, branch_id)
-                if available < qty:
-                    conn.close()
-                    return jsonify({
-                        'error': f'Insufficient stock for item {inv_id}. Available: {available}, requested: {qty}'
-                    }), 400
 
     try:
+        _validate_stock_availability(conn, data.get('items', []), branch_id)
         _validate_zero_price(conn, data.get('items', []))
         sale = process_sale(conn, data)
         conn.commit()
@@ -175,19 +178,9 @@ def create_remission():
     conn = get_tenant_conn(g.tenant_id)
 
     branch_id = data.get('branch_id', g.branch_id)
-    if not _tenant_allows_negative_stock(conn):
-        for item in data.get('items', []):
-            inv_id = item.get('inventory_id')
-            qty = int(item.get('quantity', 1))
-            if inv_id:
-                available = get_stock(conn, inv_id, branch_id)
-                if available < qty:
-                    conn.close()
-                    return jsonify({
-                        'error': f'Insufficient stock for item {inv_id}. Available: {available}, requested: {qty}'
-                    }), 400
 
     try:
+        _validate_stock_availability(conn, data.get('items', []), branch_id)
         _validate_zero_price(conn, data.get('items', []))
         sale = create_remission_note(conn, {
             'tenant_id': g.tenant_id,
@@ -753,6 +746,7 @@ def create_quotation():
     # Enrich items with inventory data (price, tax, etc.)
     try:
         enriched = _enrich_items(cur, items, data.get('customer_id'))
+        _validate_stock_availability(conn, enriched, g.branch_id)
         _validate_zero_price(conn, enriched)
     except ValueError as e:
         cur.close(); conn.close()
@@ -1142,6 +1136,7 @@ def update_quotation(quot_id):
 
     try:
         enriched = _enrich_items(cur, items, data.get('customer_id'))
+        _validate_stock_availability(conn, enriched, g.branch_id)
         _validate_zero_price(conn, enriched)
     except ValueError as e:
         cur.close(); conn.close()
@@ -1629,6 +1624,7 @@ def convert_quotation(quot_id):
     }
 
     try:
+        _validate_stock_availability(conn, items, g.branch_id)
         _validate_zero_price(conn, items)
         sale = process_sale(conn, sale_data)
 
@@ -1788,6 +1784,7 @@ def create_layaway():
     # Enrich items with inventory data
     try:
         enriched = _enrich_items(cur, items, customer_id)
+        _validate_stock_availability(conn, enriched, g.branch_id)
         _validate_zero_price(conn, enriched)
     except ValueError as e:
         cur.close(); conn.close()