HW7

app/Actions/CheckEmailAction.php

@@ -2,13 +2,22 @@
 
 namespace Rofflexor\Hw\Actions;
 
+use Exception;
+use Rofflexor\Hw\Tasks\CheckEmailDomainWithDoHTask;
 use Rofflexor\Hw\Tasks\CheckEmailTask;
 
 class CheckEmailAction
 {
+    /**
+     * @throws Exception
+     */
     public function run(string $email): false|int
     {
-        return (new CheckEmailTask())->run($email);
+        $isValidFormat = (new CheckEmailTask())->run($email);
+        if($isValidFormat) {
+            return (new CheckEmailDomainWithDoHTask())->run($email);
+        }
+        return false;
     }
 
 }

app/Tasks/CheckEmailDomainWithDoHTask.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace Rofflexor\Hw\Tasks;
+
+use Exception;
+
+class CheckEmailDomainWithDoHTask
+{
+
+    protected array $defaultServers = [
+        'Quad9 Foundation' => 'https://dns.quad9.net:5053/dns-query',
+        'Cloudflare for Teams' => 'https://security.cloudflare-dns.com/dns-query',
+        'Cloudflare' => 'https://cloudflare-dns.com/dns-query',
+        'Google' => 'https://dns.google/resolve',
+    ];
+
+    /**
+     * @throws Exception
+     */
+    public function run(string $email): bool
+    {
+        $domain = explode('@', $email)[1];
+
+        foreach ($this->defaultServers as $serverName => $urlPrefix) {
+            $url = "$urlPrefix?name={$domain}&type=MX";
+            $ch = curl_init();
+            curl_setopt($ch, CURLOPT_URL, $url);
+            curl_setopt($ch, CURLOPT_HTTPHEADER, ['accept: application/dns-json']);
+            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+            curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
+
+            $result = curl_exec($ch);
+            $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+
+            curl_close($ch);
+
+            if ($result === false || $httpCode !== 200) {
+                continue;
+            }
+
+            $json = json_decode($result, false, 512, JSON_THROW_ON_ERROR);
+
+            if (json_last_error() !== JSON_ERROR_NONE) {
+                continue;
+            }
+
+            if ($json->Status === 5) {
+                return false;
+            }
+
+            if ($json->Status !== 0) {
+                return false;
+            }
+
+            if (!isset($json->Answer) || (isset($json->Answer[0]) && $json->Answer[0]->data === '0.0.0.0')) {
+                return false;
+            }
+            return true;
+        }
+
+        throw new \RuntimeException("The DNS queries to all servers failed while validating domain of email: {$email}. Not sure what's happening but it's likely a problem on our side.");
+
+    }
+
+}

app/Tasks/CheckEmailTask.php

@@ -6,6 +6,6 @@ class CheckEmailTask
 {
     public function run(string $email): false|int
     {
-        return preg_match('/^[^()\n]*+(\((?>[^()\n]|(?1))*+\)[^()\n]*+)++$/m', $email);
+        return filter_var($email, FILTER_VALIDATE_EMAIL);
     }
 }