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'")
+    cur.execute("SELECT key, value FROM tenant_config WHERE key IN ('allow_zero_price_sales', 'allow_negative_stock')")
-    row = cur.fetchone()
+    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.
+    # Default allow_zero_price_sales to true to avoid breaking existing tenants.
-    allow = True
+    allow = str(rows.get('allow_zero_price_sales', 'true')).lower() in ('true', '1', 'yes')
-    if row:
+    # Default allow_negative_stock to false (safer).
-        allow = str(row[0]).lower() in ('true', '1', 'yes')
+    neg = str(rows.get('allow_negative_stock', 'false')).lower() in ('true', '1', 'yes')
-    return jsonify({'allow_zero_price_sales': allow})
+    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()

pos/services/service_order_engine.py

@@ -8,6 +8,16 @@ from datetime import datetime
 
 from services import inventory_engine
 
+
+def _tenant_allows_negative_stock(conn):
+    """Return True if the tenant explicitly allows selling below zero stock."""
+    cur = conn.cursor()
+    cur.execute("SELECT value FROM tenant_config WHERE key = 'allow_negative_stock'")
+    row = cur.fetchone()
+    cur.close()
+    return row is not None and str(row[0]).lower() in ('true', '1', 'yes')
+
+
 # Rached workshop statuses (applies to all tenants).
 ORDER_STATUSES = [
     'por_revisar',
@@ -612,10 +622,11 @@ def reserve_item(conn, so_item_id, branch_id, employee_id=None):
         raise ValueError("Item has no inventory linked")
 
     qty = int(quantity)
-    available = inventory_engine.get_stock(conn, inventory_id, branch_id)
+    if not _tenant_allows_negative_stock(conn):
-    if available < qty:
+        available = inventory_engine.get_stock(conn, inventory_id, branch_id)
-        cur.close()
+        if available < qty:
-        raise ValueError(f"Insufficient stock. Available: {available}, requested: {qty}")
+            cur.close()
+            raise ValueError(f"Sin stock suficiente. Disponible: {available}, solicitado: {qty}")
 
     inventory_engine.record_operation(
         conn,

pos/static/js/config.js

@@ -1021,21 +1021,27 @@ const Config = (() => {
             var res = await fetch(API + '/sales-settings', { headers: headers() });
             if (!res.ok) return;
             var data = await res.json();
-            var cb = document.getElementById('cfg-allow-zero-price');
+            var cbZero = document.getElementById('cfg-allow-zero-price');
-            if (cb) cb.checked = data.allow_zero_price_sales !== false;
+            if (cbZero) cbZero.checked = data.allow_zero_price_sales !== false;
+            var cbNeg = document.getElementById('cfg-allow-negative-stock');
+            if (cbNeg) cbNeg.checked = data.allow_negative_stock === true;
         } catch (e) {
             console.error('Config.loadSalesSettings:', e);
         }
     }
 
     async function saveSalesSettings() {
-        var cb = document.getElementById('cfg-allow-zero-price');
+        var cbZero = document.getElementById('cfg-allow-zero-price');
-        if (!cb) return;
+        var cbNeg = document.getElementById('cfg-allow-negative-stock');
+        if (!cbZero && !cbNeg) return;
         try {
+            var body = {};
+            if (cbZero) body.allow_zero_price_sales = cbZero.checked;
+            if (cbNeg) body.allow_negative_stock = cbNeg.checked;
             var res = await fetch(API + '/sales-settings', {
                 method: 'PUT',
                 headers: headers(),
-                body: JSON.stringify({ allow_zero_price_sales: cb.checked })
+                body: JSON.stringify(body)
             });
             if (!res.ok) {
                 var err = await res.json().catch(function() { return { error: res.statusText }; });

pos/static/js/pos.js

@@ -33,6 +33,7 @@ const POS = (() => {
     let canCreateRemission = false;
     let counterRemissionEnabled = false;
     let allowZeroPriceSales = true;
+    let allowNegativeStock = false;
     let currentPerms = [];
     let receiptConfig = {};
     let couriers = [];
@@ -143,12 +144,14 @@ const POS = (() => {
             } catch (e) {
                 counterRemissionEnabled = false;
             }
-            // Sales settings (zero-price sales toggle)
+            // Sales settings (zero-price and negative-stock toggles)
             try {
                 const ssCfg = await api('/pos/api/config/sales-settings');
                 allowZeroPriceSales = ssCfg.allow_zero_price_sales !== false;
+                allowNegativeStock = ssCfg.allow_negative_stock === true;
             } catch (e) {
                 allowZeroPriceSales = true;
+                allowNegativeStock = false;
             }
             // Counter remission workflow applies only to the counter role.
             canCreateRemission = counterRemissionEnabled && employeeRole === 'counter' && perms.includes('pos.remission');

pos/static/pwa/sw.js

@@ -6,7 +6,7 @@
 // The fetch handler normalizes static asset URLs (strips ?v= query strings)
 // so templates can use cache-busting query params freely.
 
-const VERSION = 44;
+const VERSION = 45;
 const CACHE_NAME = 'nexus-pos-v' + VERSION;
 
 const APP_SHELL = [

pos/templates/config.html

@@ -746,6 +746,16 @@
                 <span class="toggle__slider"></span>
               </label>
             </div>
+            <div class="toggle-row">
+              <div class="toggle-row__info">
+                <span class="toggle-row__label">Permitir venta sin stock</span>
+                <span class="toggle-row__desc">Permite vender aunque no haya existencias suficientes en la sucursal (stock negativo)</span>
+              </div>
+              <label class="toggle">
+                <input type="checkbox" id="cfg-allow-negative-stock" />
+                <span class="toggle__slider"></span>
+              </label>
+            </div>
           </div>
         </div>