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'])