<?php

require __DIR__ . "/Classes/BaseHandler.php";

use App\Classes\BaseHandler;
use GuzzleHttp\Client;

class ContactHandler extends BaseHandler
{
  protected string $postgrestUrl;
  protected string $postgrestApiKey;

  private string $forwardEmailApiKey;
  private Client $httpClient;

  public function __construct(?Client $httpClient = null)
  {
    $this->httpClient = $httpClient ?? new Client();
    $this->loadEnvironment();
  }

  private function loadEnvironment(): void
  {
    $this->postgrestUrl = $_ENV["POSTGREST_URL"] ?? getenv("POSTGREST_URL");
    $this->postgrestApiKey =
      $_ENV["POSTGREST_API_KEY"] ?? getenv("POSTGREST_API_KEY");
    $this->forwardEmailApiKey =
      $_ENV["FORWARDEMAIL_API_KEY"] ?? getenv("FORWARDEMAIL_API_KEY");
  }

  public function handleRequest(): void
  {
    try {
      $this->validateReferer();
      $this->checkRateLimit();
      $this->enforceHttps();

      $contentType = $_SERVER["CONTENT_TYPE"] ?? "";
      $formData = null;

      if (strpos($contentType, "application/json") !== false) {
        $rawBody = file_get_contents("php://input");
        $formData = json_decode($rawBody, true);
        if (!$formData || !isset($formData["data"])) {
          throw new Exception("Invalid JSON payload.");
        }
        $formData = $formData["data"];
      } elseif (
        strpos($contentType, "application/x-www-form-urlencoded") !== false
      ) {
        $formData = $_POST;
      } else {
        $this->sendErrorResponse(
          "Unsupported Content-Type. Use application/json or application/x-www-form-urlencoded.",
          400
        );
      }

      if (!empty($formData["hp_name"])) $this->sendErrorResponse("Invalid submission.", 400);

      $name = htmlspecialchars(
        trim($formData["name"] ?? ""),
        ENT_QUOTES,
        "UTF-8"
      );
      $email = filter_var($formData["email"] ?? "", FILTER_VALIDATE_EMAIL);
      $message = htmlspecialchars(
        trim($formData["message"] ?? ""),
        ENT_QUOTES,
        "UTF-8"
      );

      if (empty($name)) $this->sendErrorResponse("Name is required.", 400);
      if (!$email) $this->sendErrorResponse("Valid email is required.", 400);
      if (empty($message)) $this->sendErrorResponse("Message is required.", 400);
      if (strlen($name) > 100) $this->sendErrorResponse(
          "Name is too long. Max 100 characters allowed.",
          400
        );
      if (strlen($message) > 1000) $this->sendErrorResponse(
          "Message is too long. Max 1000 characters allowed.",
          400
        );
      if ($this->isBlockedDomain($email)) $this->sendErrorResponse("Submission from blocked domain.", 400);

      $contactData = [
        "name" => $name,
        "email" => $email,
        "message" => $message,
        "replied" => false,
      ];

      $this->saveToDatabase($contactData);
      $this->sendNotificationEmail($contactData);
      $this->sendRedirect("/contact/success");
    } catch (Exception $e) {
      error_log("Error handling contact form submission: " . $e->getMessage());
      $this->sendErrorResponse($e->getMessage(), 400);
    }
  }

  private function validateReferer(): void
  {
    $referer = $_SERVER["HTTP_REFERER"] ?? "";
    $allowedDomain = "coryd.dev";
    if (!str_contains($referer, $allowedDomain)) throw new Exception("Invalid submission origin.");
  }

  private function checkRateLimit(): void
  {
    $ipAddress = $_SERVER["REMOTE_ADDR"] ?? "unknown";
    $cacheFile = sys_get_temp_dir() . "/rate_limit_" . md5($ipAddress);
    $rateLimitDuration = 60;
    $maxRequests = 5;

    if (file_exists($cacheFile)) {
      $data = json_decode(file_get_contents($cacheFile), true);
      if (
        $data["timestamp"] + $rateLimitDuration > time() &&
        $data["count"] >= $maxRequests
      ) {
        header("Location: /429", true, 302);
        exit();
      }
      $data["count"]++;
    } else {
      $data = ["count" => 1, "timestamp" => time()];
    }

    file_put_contents($cacheFile, json_encode($data));
  }

  private function enforceHttps(): void
  {
    if (empty($_SERVER["HTTPS"]) || $_SERVER["HTTPS"] !== "on") throw new Exception("Secure connection required. Use HTTPS.");
  }

  private function isBlockedDomain(string $email): bool
  {
    $domain = substr(strrchr($email, "@"), 1);
    if (!$domain) return false;

    $response = $this->httpClient->get(
      "{$this->postgrestUrl}/blocked_domains",
      [
        "headers" => [
          "Content-Type" => "application/json",
          "Authorization" => "Bearer {$this->postgrestApiKey}",
        ],
        "query" => [
          "domain_name" => "eq.{$domain}",
          "limit" => 1,
        ],
      ]
    );

    $blockedDomains = json_decode($response->getBody(), true);

    return !empty($blockedDomains);
  }

  private function saveToDatabase(array $contactData): void
  {
    $response = $this->httpClient->post("{$this->postgrestUrl}/contacts", [
      "headers" => [
        "Content-Type" => "application/json",
        "Authorization" => "Bearer {$this->postgrestApiKey}",
      ],
      "json" => $contactData,
    ]);

    if ($response->getStatusCode() >= 400) {
      $errorResponse = json_decode($response->getBody(), true);
      throw new Exception(
        "PostgREST error: " . ($errorResponse["message"] ?? "Unknown error")
      );
    }
  }

  private function sendNotificationEmail(array $contactData): void
  {
    $authHeader = "Basic " . base64_encode("{$this->forwardEmailApiKey}:");
    $emailSubject = "Contact form submission";
    $emailText = sprintf(
      "Name: %s\nEmail: %s\nMessage: %s\n",
      $contactData["name"],
      $contactData["email"],
      $contactData["message"]
    );
    $response = $this->httpClient->post(
      "https://api.forwardemail.net/v1/emails",
      [
        "headers" => [
          "Content-Type" => "application/x-www-form-urlencoded",
          "Authorization" => $authHeader,
        ],
        "form_params" => [
          "from" => "coryd.dev <hi@admin.coryd.dev>",
          "to" => "hi@coryd.dev",
          "subject" => $emailSubject,
          "text" => $emailText,
          "replyTo" => $contactData["email"],
        ],
      ]
    );

    if ($response->getStatusCode() >= 400) throw new Exception("Failed to send email notification.");
  }

  private function sendRedirect(string $path): void
  {
    $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? "https" : "http";
    $host = $_SERVER['HTTP_HOST'];
    $redirectUrl = "{$protocol}://{$host}{$path}";

    header("Location: $redirectUrl", true, 302);
    exit();
  }
}

try {
  $handler = new ContactHandler();
  $handler->handleRequest();
} catch (Exception $e) {
  error_log("Contact form error: " . $e->getMessage());
  echo json_encode(["error" => $e->getMessage()]);
  http_response_code(500);
}