feat: ✨ get next available ip by api

.devcontainer/devcontainer.json

@@ -6,7 +6,11 @@
   "settings": {},
   "customizations": {
     "vscode": {
-      "extensions": ["ms-python.python"]
+      "extensions": [
+        "ms-python.python",
+        "vivaxy.vscode-conventional-commits",
+        "esbenp.prettier-vscode"
+      ]
     }
   },
   "postCreateCommand": "pip install -r requirements.txt; curl -sLO https://github.com/tailwindlabs/tailwindcss/releases/latest/download/tailwindcss-linux-x64; chmod +x tailwindcss-linux-x64; mv tailwindcss-linux-x64 tailwindcss",

routes.py

@@ -2805,6 +2805,33 @@ def register_routes(app):
             subnet['ip_addresses'] = cursor.fetchall()
         return jsonify(subnet)
     
+    @app.route('/api/v1/subnets/<int:subnet_id>/next_free_ip', methods=['GET'])
+    @api_permission_required('view_subnet')
+    def api_subnet_next_free_ip(subnet_id):
+        """Get the next free IP address in a subnet"""
+        from flask import current_app
+        with get_db_connection(current_app) as conn:
+            cursor = conn.cursor(dictionary=True)
+            # First check if subnet exists
+            cursor.execute('SELECT id FROM Subnet WHERE id = %s', (subnet_id,))
+            if not cursor.fetchone():
+                return jsonify({'error': 'Subnet not found'}), 404
+            
+            # Find the first IP in the subnet that is not assigned to any device
+            cursor.execute('''
+                SELECT ip.id, ip.ip
+                FROM IPAddress ip
+                LEFT JOIN DeviceIPAddress dia ON ip.id = dia.ip_id
+                WHERE ip.subnet_id = %s AND dia.ip_id IS NULL
+                ORDER BY INET_ATON(ip.ip)
+                LIMIT 1
+            ''', (subnet_id,))
+            result = cursor.fetchone()
+            if not result:
+                return jsonify({'error': 'No free IP addresses available in this subnet'}), 404
+            
+            return jsonify({'id': result['id'], 'ip': result['ip']})
+    
     @app.route('/api/v1/subnets', methods=['POST'])
     @api_permission_required('add_subnet')
     def api_add_subnet():

templates/api_docs.html

@@ -177,6 +177,7 @@
                                     <ul class="list-disc list-inside space-y-1 text-sm">
                                         <li><code class="bg-gray-400 dark:bg-zinc-600 px-2 py-1 rounded text-xs">GET /api/v1/subnets</code> - List all subnets</li>
                                         <li><code class="bg-gray-400 dark:bg-zinc-600 px-2 py-1 rounded text-xs">GET /api/v1/subnets/{id}</code> - Get subnet details</li>
+                                        <li><code class="bg-gray-400 dark:bg-zinc-600 px-2 py-1 rounded text-xs">GET /api/v1/subnets/{id}/next_free_ip</code> - Get next free IP address</li>
                                     </ul>
                                 </div>
                                 <div>