<?php

require __DIR__ . "/../vendor/autoload.php";

use App\Classes\ApiHandler;
use GuzzleHttp\Client;

class MastodonPostHandler extends ApiHandler
{
  private string $mastodonAccessToken;
  private string $rssFeedUrl = "https://www.coryd.dev/feeds/syndication.xml";
  private string $baseUrl = "https://www.coryd.dev";

  private const MASTODON_API_STATUS = "https://follow.coryd.dev/api/v1/statuses";

  private Client $httpClient;

  public function __construct(?Client $httpClient = null)
  {
    parent::__construct();
    $this->ensureCliAccess();

    $this->mastodonAccessToken = getenv("MASTODON_ACCESS_TOKEN") ?: $_ENV["MASTODON_ACCESS_TOKEN"] ?? "";
    $this->httpClient = $httpClient ?: new Client();

    $this->validateAuthorization();
  }

  private function validateAuthorization(): void
  {
    $authHeader = $_SERVER["HTTP_AUTHORIZATION"] ?? "";
    $expectedToken = "Bearer " . getenv("MASTODON_SYNDICATION_TOKEN");

    if ($authHeader !== $expectedToken) {
      http_response_code(401);
      echo json_encode(["error" => "Unauthorized"]);
      exit();
    }
  }

  public function handlePost(): void
  {
    if (!$this->isDatabaseAvailable()) {
      echo "Database is unavailable. Exiting.\n";
      return;
    }

    $latestItems = $this->fetchRSSFeed($this->rssFeedUrl);

    foreach (array_reverse($latestItems) as $item) {
      $existing = $this->fetchFromApi("mastodon_posts", "link=eq." . urlencode($item["link"]));
      if (!empty($existing)) continue;

      $content = $this->truncateContent(
        $item["title"],
        strip_tags($item["description"]),
        $item["link"],
        500
      );

      $timestamp = date("Y-m-d H:i:s");

      if (!$this->storeInDatabase($item["link"], $timestamp)) {
        echo "Skipping post: database write failed for {$item["link"]}\n";
        continue;
      }

      $postedUrl = $this->postToMastodon($content, $item["image"] ?? null);
      if ($postedUrl) {
        echo "Posted: {$postedUrl}\n";
      } else {
        echo "Failed to post to Mastodon for: {$item["link"]}\n";
      }
    }

    echo "RSS processed successfully.\n";
  }

  private function fetchRSSFeed(string $rssFeedUrl): array
  {
    $rssText = file_get_contents($rssFeedUrl);
    if (!$rssText) throw new \Exception("Failed to fetch RSS feed.");

    $rss = new \SimpleXMLElement($rssText);
    $items = [];

    foreach ($rss->channel->item as $item) {
      $items[] = [
        "title" => (string) $item->title,
        "link" => (string) $item->link,
        "description" => (string) $item->description,
      ];
    }

    return $items;
  }

  private function postToMastodon(string $content): ?string
  {
    $headers = [
      "Authorization" => "Bearer {$this->mastodonAccessToken}",
      "Content-Type" => "application/json",
    ];
    $postData = ["status" => $content];
    $response = $this->httpClient->request("POST", self::MASTODON_API_STATUS, [
      "headers" => $headers,
      "json" => $postData
    ]);
    if ($response->getStatusCode() >= 400) throw new \Exception("Mastodon post failed: {$response->getBody()}");

    $body = json_decode($response->getBody()->getContents(), true);
    return $body["url"] ?? null;
  }

  private function storeInDatabase(string $link, string $timestamp): bool
  {
    try {
      $this->makeRequest("POST", "mastodon_posts", [
        "json" => [
          "link" => $link,
          "created_at" => $timestamp
        ]
      ]);
      return true;
    } catch (\Exception $e) {
      echo "Error storing post in DB: " . $e->getMessage() . "\n";
      return false;
    }
  }

  private function isDatabaseAvailable(): bool
  {
    try {
      $response = $this->fetchFromApi("mastodon_posts", "limit=1");
      return is_array($response);
    } catch (\Exception $e) {
      echo "Database check failed: " . $e->getMessage() . "\n";
      return false;
    }
  }

  private function truncateContent(string $title, string $description, string $link, int $maxLength): string
  {
    $baseLength = strlen("$title\n\n$link");
    $available = $maxLength - $baseLength - 4;

    if (strlen($description) > $available) {
      $description = substr($description, 0, $available);
      $description = preg_replace('/\s+\S*$/', "", $description) . "...";
    }

    return "$title\n\n$description\n\n$link";
  }
}

try {
  $handler = new MastodonPostHandler();
  $handler->handlePost();
} catch (\Exception $e) {
  http_response_code(500);
  echo json_encode(["error" => $e->getMessage()]);
}