validate whether the user is detaching a node that's using IPs from t…

…he pool

app/Http/Requests/Admin/AddressPools/UpdateAddressPoolRequest.php

@@ -2,13 +2,16 @@
 
 namespace Convoy\Http\Requests\Admin\AddressPools;
 
+use Convoy\Models\Node;
 use Convoy\Models\AddressPool;
+use Illuminate\Validation\Validator;
 use Convoy\Http\Requests\FormRequest;
 
 class UpdateAddressPoolRequest extends FormRequest
 {
     public function rules(): array
     {
+        /** @var AddressPool $addressPool */
         $addressPool = $this->parameter('address_pool', AddressPool::class);
 
         return [
@@ -20,7 +23,36 @@ public function rules(): array
 
     public function after(): array
     {
-        // TODO: if nodes are removed, check whether their servers are using any of IPs from this pool before unmounting
-        return [];
+        /** @var AddressPool $addressPool */
+        $addressPool = $this->parameter('address_pool', AddressPool::class);
+
+        return [
+            function (Validator $validator) use ($addressPool) {
+                /** @var int[] $nodeIdsToSync */
+                if ($nodeIdsToSync = $this->node_ids) {
+                    $existingAttachedNodeIds = $addressPool->nodes()->pluck('id');
+
+                    $nodeIdsRemoved = $existingAttachedNodeIds->diff($nodeIdsToSync);
+
+                    $isAddressesAllocated = Node::whereIn('nodes.id', $nodeIdsRemoved)->join(
+                        'servers',
+                        'nodes.id',
+                        '=',
+                        'servers.node_id',
+                    )
+                        ->join('ip_addresses', 'servers.id', '=', 'ip_addresses.server_id')
+                        ->where(
+                            'ip_addresses.address_pool_id',
+                            '=',
+                            $addressPool->id,
+                        )
+                        ->exists();
+
+                    if ($isAddressesAllocated) {
+                        $validator->errors()->add('node_ids', 'Cannot detach nodes with servers using addresses from this pool.');
+                    }
+                }
+            },
+        ];
     }
 }