feat: ✨ subnet utilisation stats

routes.py

@@ -172,7 +172,8 @@ def register_routes(app):
     @permission_required('view_index')
     def index():
         from flask import current_app
-        with get_db_connection(current_app) as conn:
+        conn = get_db_connection(current_app)
+        try:
             cursor = conn.cursor()
             cursor.execute('SELECT id, name, cidr, site FROM Subnet')
             subnets = cursor.fetchall()
@@ -181,8 +182,36 @@ def register_routes(app):
                 site = subnet[3] or 'Unassigned'
                 if site not in sites_subnets:
                     sites_subnets[site] = []
-            sites_subnets[site].append({'id': subnet[0], 'name': subnet[1], 'cidr': subnet[2]})
+                
+                # Calculate utilization for each subnet
+                subnet_id = subnet[0]
+                cursor.execute('SELECT COUNT(*) FROM IPAddress WHERE subnet_id = %s', (subnet_id,))
+                total_ips = cursor.fetchone()[0]
+                
+                cursor.execute('''
+                    SELECT COUNT(*) FROM IPAddress ip
+                    WHERE ip.subnet_id = %s AND ip.id IN (SELECT ip_id FROM DeviceIPAddress)
+                ''', (subnet_id,))
+                assigned_ips = cursor.fetchone()[0]
+                
+                cursor.execute('''
+                    SELECT COUNT(*) FROM IPAddress ip
+                    WHERE ip.subnet_id = %s AND ip.hostname = 'DHCP' AND ip.id NOT IN (SELECT ip_id FROM DeviceIPAddress)
+                ''', (subnet_id,))
+                dhcp_ips = cursor.fetchone()[0]
+                
+                used_ips = assigned_ips + dhcp_ips
+                utilization_percent = (used_ips / total_ips * 100) if total_ips > 0 else 0
+                
+                sites_subnets[site].append({
+                    'id': subnet[0],
+                    'name': subnet[1],
+                    'cidr': subnet[2],
+                    'utilization': round(utilization_percent, 1)
+                })
             return render_with_user('index.html', sites_subnets=sites_subnets)
+        finally:
+            conn.close()
 
     @app.route('/devices')
     @permission_required('view_devices')
@@ -504,6 +533,35 @@ def register_routes(app):
             subnet = cursor.fetchone()
             cursor.execute('SELECT * FROM IPAddress WHERE subnet_id = %s', (subnet_id,))
             ip_addresses = cursor.fetchall()
+            
+            # Calculate utilization stats
+            cursor.execute('SELECT COUNT(*) FROM IPAddress WHERE subnet_id = %s', (subnet_id,))
+            total_ips = cursor.fetchone()[0]
+            
+            cursor.execute('''
+                SELECT COUNT(*) FROM IPAddress ip
+                WHERE ip.subnet_id = %s AND ip.id IN (SELECT ip_id FROM DeviceIPAddress)
+            ''', (subnet_id,))
+            assigned_ips = cursor.fetchone()[0]
+            
+            cursor.execute('''
+                SELECT COUNT(*) FROM IPAddress ip
+                WHERE ip.subnet_id = %s AND ip.hostname = 'DHCP' AND ip.id NOT IN (SELECT ip_id FROM DeviceIPAddress)
+            ''', (subnet_id,))
+            dhcp_ips = cursor.fetchone()[0]
+            
+            available_ips = total_ips - assigned_ips - dhcp_ips
+            used_ips = assigned_ips + dhcp_ips
+            utilization_percent = (used_ips / total_ips * 100) if total_ips > 0 else 0
+            
+            utilization_stats = {
+                'total': total_ips,
+                'assigned': assigned_ips,
+                'dhcp': dhcp_ips,
+                'available': available_ips,
+                'percent': round(utilization_percent, 1)
+            }
+            
             cursor.execute('SELECT id, name, description FROM Device')
             devices = cursor.fetchall()
             device_name_map = {name.lower(): (id, description) for id, name, description in devices}
@@ -517,7 +575,7 @@ def register_routes(app):
                     if match:
                         device_id, device_description = match
                 ip_addresses_with_device.append((ip[0], ip[1], hostname, device_id, device_description))
-        return render_with_user('subnet.html', subnet={'id': subnet[0], 'name': subnet[1], 'cidr': subnet[2]}, ip_addresses=ip_addresses_with_device)
+        return render_with_user('subnet.html', subnet={'id': subnet[0], 'name': subnet[1], 'cidr': subnet[2]}, ip_addresses=ip_addresses_with_device, utilization=utilization_stats)
 
     @app.route('/add_subnet', methods=['POST'])
     @permission_required('add_subnet')
@@ -594,7 +652,42 @@ def register_routes(app):
         with get_db_connection(current_app) as conn:
             cursor = conn.cursor()
             cursor.execute('SELECT id, name, cidr, site FROM Subnet ORDER BY site, name')
-            subnets = [dict(id=row[0], name=row[1], cidr=row[2], site=row[3] or 'Unassigned') for row in cursor.fetchall()]
+            subnet_rows = cursor.fetchall()
+            subnets = []
+            for row in subnet_rows:
+                subnet_id = row[0]
+                # Calculate utilization for each subnet
+                cursor.execute('SELECT COUNT(*) FROM IPAddress WHERE subnet_id = %s', (subnet_id,))
+                total_ips = cursor.fetchone()[0]
+                
+                cursor.execute('''
+                    SELECT COUNT(*) FROM IPAddress ip
+                    WHERE ip.subnet_id = %s AND ip.id IN (SELECT ip_id FROM DeviceIPAddress)
+                ''', (subnet_id,))
+                assigned_ips = cursor.fetchone()[0]
+                
+                cursor.execute('''
+                    SELECT COUNT(*) FROM IPAddress ip
+                    WHERE ip.subnet_id = %s AND ip.hostname = 'DHCP' AND ip.id NOT IN (SELECT ip_id FROM DeviceIPAddress)
+                ''', (subnet_id,))
+                dhcp_ips = cursor.fetchone()[0]
+                
+                available_ips = total_ips - assigned_ips - dhcp_ips
+                used_ips = assigned_ips + dhcp_ips
+                utilization_percent = (used_ips / total_ips * 100) if total_ips > 0 else 0
+                
+                subnets.append({
+                    'id': row[0],
+                    'name': row[1],
+                    'cidr': row[2],
+                    'site': row[3] or 'Unassigned',
+                    'utilization': {
+                        'percent': round(utilization_percent, 1),
+                        'assigned': assigned_ips,
+                        'used': used_ips,
+                        'total': total_ips
+                    }
+                })
         return render_with_user('admin.html', subnets=subnets, 
                                can_add_subnet=has_permission('add_subnet'),
                                can_edit_subnet=has_permission('edit_subnet'),
@@ -1676,8 +1769,6 @@ def register_routes(app):
                             reserved_for_dhcp = True
                             break
                         if candidate_ip == end_ip:
-                            if candidate_ip == ip:
-                                reserved_for_dhcp = True
                             in_range = False
                     if reserved_for_dhcp:
                         return jsonify({'error': 'This IP is reserved for DHCP and cannot be assigned to a device'}), 400

templates/admin.html

@@ -85,6 +85,7 @@
                                 <th class="text-center p-3">Name</th>
                                 <th class="text-center p-3">CIDR</th>
                                 <th class="text-center p-3">Site</th>
+                                <th class="text-center p-3">Utilisation</th>
                                 <th class="text-center p-3">Actions</th>
                             </tr>
                         </thead>
@@ -96,6 +97,14 @@
                                 <td class="p-3 text-center">
                                     <span class="px-2 py-1 bg-gray-300 dark:bg-zinc-700 rounded text-sm">{{ subnet.site }}</span>
                                 </td>
+                                <td class="p-3 text-center">
+                                    {% if subnet.utilization %}
+                                    <span class="text-sm text-gray-600 dark:text-gray-400">{{ subnet.utilization.percent }}%</span>
+                                    <span class="text-xs text-gray-500 dark:text-gray-500 ml-1">({{ subnet.utilization.used }}/{{ subnet.utilization.total }})</span>
+                                    {% else %}
+                                    <span class="text-sm text-gray-500">—</span>
+                                    {% endif %}
+                                </td>
                                 <td class="p-3 text-center">
                                     <div class="flex items-center justify-center space-x-2">
                                         <a href="/subnet/{{ subnet.id }}" class="text-gray-900 hover:text-gray-600 dark:text-gray-100 dark:hover:text-gray-300" title="View Subnet">

templates/subnet.html

@@ -20,6 +20,19 @@
                     <i class="fas fa-file-csv fa-lg"></i>
                 </button>
             </div>
+            {% if utilization %}
+            <div class="hidden sm:flex justify-center mb-4">
+                <div class="bg-gray-200 dark:bg-zinc-800 px-4 py-2 rounded-lg text-sm">
+                    <span class="font-medium">{{ utilization.percent }}% used</span>
+                    <span class="text-gray-600 dark:text-gray-400 mx-2">•</span>
+                    <span class="text-gray-600 dark:text-gray-400">{{ utilization.assigned }} assigned</span>
+                    <span class="text-gray-600 dark:text-gray-400 mx-2">•</span>
+                    <span class="text-gray-600 dark:text-gray-400">{{ utilization.dhcp }} DHCP</span>
+                    <span class="text-gray-600 dark:text-gray-400 mx-2">•</span>
+                    <span class="text-gray-600 dark:text-gray-400">{{ utilization.available }} available</span>
+                </div>
+            </div>
+            {% endif %}
             <div class="flex justify-center mb-4">
                 <a href="/subnet/{{ subnet.id }}/dhcp" class="hidden sm:flex bg-gray-200 hover:bg-gray-400 dark:bg-zinc-700 dark:hover:bg-zinc-600 px-4 py-2 rounded-lg shadow items-center gap-2">
                     <i class="fas fa-network-wired"></i> Define DHCP Pool