validação do link de grupo de pesquisa

app/Http/Controllers/TrabalhoController.php

@@ -93,7 +93,7 @@ class TrabalhoController extends Controller
           'area'                    => ['required', 'string'],
           'subArea'                 => ['required', 'string'],
           'pontuacaoPlanilha'       => ['required', 'string'],
-          'linkGrupo'               => ['required', 'string'],
+          'linkGrupo'               => ['required', 'string', 'link_grupo'],
           'linkLattesEstudante'     => ['required', 'string', 'link_lattes'],
           'nomeParticipante.*'      => ['required', 'string'],
           'emailParticipante.*'     => ['required', 'string'],
@@ -142,7 +142,7 @@ class TrabalhoController extends Controller
           'area'                    => ['required', 'string'],
           'subArea'                 => ['required', 'string'],
           'pontuacaoPlanilha'       => ['required', 'string'],
-          'linkGrupo'               => ['required', 'string'],
+          'linkGrupo'               => ['required', 'string', 'link_grupo'],
           'linkLattesEstudante'     => ['required', 'string', 'link_lattes'],
           'nomeParticipante.*'      => ['required', 'string'],
           'emailParticipante.*'     => ['required', 'string'],

app/Providers/AppServiceProvider.php

@@ -26,5 +26,6 @@ class AppServiceProvider extends ServiceProvider
     {
         Validator::extend('cpf', '\App\Utils\CpfValidation@validate');    
         Validator::extend('link_lattes', '\App\Utils\LattesValidation@validate', 'Link inválido');
+        Validator::extend('link_grupo', '\App\Utils\GrupoPesquisaValidation@validate', 'Link inválido');
     }
 }

app/Utils/GrupoPesquisaValidation.php

+<?php namespace App\Utils;
+
+class GrupoPesquisaValidation
+{
+    public function validate($attribute, $value, $parameters, $validator)
+    {
+        return $this->isValidUrl($value);
+    }
+
+    function isValidUrl($url)
+    {
+        // first do some quick sanity checks:
+        if (!$url || !is_string($url)) {
+            return false;
+        }
+
+        $url = filter_var($url, FILTER_SANITIZE_URL);
+
+        // Validate url
+        if (!filter_var($url, FILTER_VALIDATE_URL)) {
+            return false;
+        } 
+
+        // if(parse_url($url)['host'] != 'dgp.cnpq.br'){
+        //      return false;
+        // }
+        
+        if($this->getHttpResponseCode_using_getheaders($url) != 200){ 
+            return false;
+        }
+        
+        return true;
+    }
+
+    function getHttpResponseCode_using_getheaders($url, $followredirects = true)
+    {        
+        if (!$url || !is_string($url)) {
+            return false;
+        }
+        $headers = @get_headers($url);
+        if ($headers && is_array($headers)) {
+            if ($followredirects) {                
+                $headers = array_reverse($headers);
+            }
+            foreach ($headers as $hline) {               
+                if (preg_match('/^HTTP\/\S+\s+([1-9][0-9][0-9])\s+.*/', $hline, $matches)) { 
+                    $code = $matches[1];
+                    return $code;
+                }
+            }           
+            return false;
+        }        
+        return false;
+    }
+}
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