<?php
/*************************************************************
# 076 License

Copyright (c) テクニカル諏訪子

Permission is hereby granted to any person obtaining a copy of the software
Little Beast (the "Software") to use, modify, merge, copy, publish, distribute,
sublicense, and/or sell copies of the Software, subject to the following conditions:

    1. **Origin Attribution**:
       - You must not misrepresent the origin of the Software; you must not claim
         you created the original Software.
       - If the Software is used in a product, you must either:
         a. Provide clear attribution in the product's documentation, user interface,
            or other visible areas, **OR**
         b. Pay the original developers a fee they specify in writing.
    2. **Usage Restriction**:
       - The Software, or any derivative works, dependencies, or libraries
         incorporating it, must not be used for censorship or to suppress freedom of
         speech, expression, or creativity. Prohibited uses include, but are not
         limited to:
         - Censorship of so-called "hate speech", visuals, non-mainstream opinions,
           ideas, or objective reality.
         - Tools or systems designed to restrict access to information or
           artistic works.
    3. **Notice Preservation**:
       - This license and the above copyright notice must remain intact in all copies
         of the source code.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
namespace Site\Controller;

use Site\Controller\BlogPost;
use Site\Controller\Mods;
use Std\Lib\Activitypub;
use Std\Lib\Fedi\Actor;
use Std\Lib\Fedi\Fedi;
use Std\Lib\Fedi\Inbox;
use Std\Lib\Fedi\Notes;
use Std\Lib\Fedi\Timeline;
use LogType;

class Fediverse extends BlogPost {
  use Mods;

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apfinger(array $params): void {
    try {
      // マルチユーザーでは「resource」でユーザーを探す（ブログのアクター以外）
      $resource = is_string($_GET['resource'] ?? null) ? $_GET['resource'] : '';
      if (Fedi::enabled() && $resource !== '' && !$this->isBlogResource($resource)) {
        // Gitlerのリポジトリ（acct:所有者.名前@ホスト）
        $jrd = Actor::webfinger($resource) ?? (\Std\Lib\Gitler\Gitler::enabled() ? \Std\Lib\Gitler\Federation::webfinger($resource) : null);
        if ($jrd === null) $this->json(404, ['error' => '見つかりません'], 'application/jrd+json');
        $this->json(200, $jrd, 'application/jrd+json');
      }
      header('Content-Type: application/jrd+json');
      $ap = new Activitypub();
      echo $ap->getWebfinger();
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apactor(array $params): void {
    try {
      header('Content-Type: application/activity+json');
      $ap = new Activitypub();
      echo $ap->getActor();
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apinbox(array $params): void {
    if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
      header('HTTP/1.1 405 Method Not Allowed');
      header('Allow: POST');
      exit;
    }

    $maxBody = 262144;
    $input = file_get_contents('php://input', false, null, 0, $maxBody + 1);
    if ($input === false || strlen($input) > $maxBody) {
      header('HTTP/1.1 413 Payload Too Large');
      exit;
    }

    $activity = json_decode($input, true);
    if (!is_array($activity) || !isset($activity['type']) || !is_string($activity['type'])) {
      header('HTTP/1.1 400 Bad Request');
      header('Content-Type: application/activity+json');
      echo json_encode(['error' => '不正なアクティビティ']);
      exit;
    }

    try {
      header('Content-Type: application/activity+json');
      // 投稿はコメント（ブログの投稿への返信）の処理で必要になった時だけ読む
      $ap = new Activitypub(fn() => $this->federatedPosts());

      if (!$ap->verifyInboxSignature($input, $activity)) {
        // 削除されたアカウントのDeleteは鍵がもう取得出来ないので検証出来ない。拒否すると何日も再送されるので受け流す
        if ($activity['type'] === 'Delete') {
          header('HTTP/1.1 202 Accepted');
          echo json_encode(['status' => '無視しました']);
          exit;
        }
        header('HTTP/1.1 401 Unauthorized');
        echo json_encode(['error' => '署名の検証に失敗']);
        exit;
      }

      logger(\LogType::ActivityPub, "受付に入れた：".json_encode($activity));
      // ブログの投稿への返信は記事のコメントにする（マルチユーザーでも、ユーザー宛ての処理は続ける）
      $ap->handleComments($activity);
      // マルチユーザーでは共有の受付ボックス（ブログのアクター宛てはInboxからActivitypubに渡す）
      if (Fedi::enabled()) {
        [$code, $body] = Inbox::handle($activity);
        $this->json($code, $body);
      }
      $ap->postInbox($activity);
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * ユーザーのアクター（/ap/users/{name}）。ブラウザからはプロフィールのページに移動する
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function apuser(array $params): void {
    $u = $this->actorOr404($params);
    if ($this->wantsHtml()) {
      header('Location: /microblog/user/'.$u->username);
      exit;
    }
    $this->json(200, Actor::document($u));
  }

  /**
   * ユーザーの受付ボックス（POST /ap/users/{name}/inbox）。処理は共有の受付ボックスと同じ
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function apuserinbox(array $params): void {
    $this->actorOr404($params);
    $this->apinbox($params);
  }

  /**
   * ユーザーの送信ボックス（公開・未収載の投稿とブースト、20件ずつ）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function apuseroutbox(array $params): void {
    $u = $this->actorOr404($params);
    $url = Fedi::actorUrl($u->username).'/outbox';
    $me = Fedi::actorUrl($u->username);
    $entries = array_values(array_filter(Timeline::entries(), fn($e) => $e['actor'] === $me && in_array($e['vis'], ['public', 'unlisted'], true)));
    usort($entries, fn($a, $b) => $b['t'] <=> $a['t']);
    $total = count($entries);

    if (!isset($_GET['page'])) {
      $this->json(200, ['@context' => 'https://www.w3.org/ns/activitystreams', 'id' => $url, 'type' => 'OrderedCollection',
                        'totalItems' => $total, 'first' => "{$url}?page=1", 'last' => "{$url}?page=".max(1, (int)ceil($total / 20))]);
    }

    $page = max(1, (int)$_GET['page']);
    $boostIds = Fedi::read(Fedi::userPath($u->username, 'boosts.json'));
    $items = [];
    foreach (array_slice($entries, ($page - 1) * 20, 20) as $e) {
      if ($e['type'] === 'boost') {
        $items[] = ['id' => $boostIds[$e['object']] ?? $me.'#boosts/'.sha1($e['object']), 'type' => 'Announce', 'actor' => $me, 'published' => Fedi::now((int)$e['t']),
                    'to' => [Fedi::PUBLIC], 'cc' => [$me.'/followers'], 'object' => $e['object']];
        continue;
      }
      $ids = Fedi::localNoteId($e['object']);
      $note = $ids ? Notes::get($ids[1]) : null;
      if (!$note) continue;
      $create = Notes::toCreate($note);
      unset($create['@context'], $create['object']['@context']);
      $items[] = $create;
    }
    $data = ['@context' => Fedi::CONTEXT, 'id' => "{$url}?page={$page}", 'type' => 'OrderedCollectionPage', 'partOf' => $url, 'orderedItems' => $items];
    if ($page * 20 < $total) $data['next'] = "{$url}?page=".($page + 1);
    if ($page > 1) $data['prev'] = "{$url}?page=".($page - 1);
    $this->json(200, $data);
  }

  /**
   * フォロワー・フォロー（数だけ公開する）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function apuserfollowers(array $params): void {
    $u = $this->actorOr404($params);
    $this->json(200, Actor::collection($u->username, 'followers'));
  }

  public function apuserfollowing(array $params): void {
    $u = $this->actorOr404($params);
    $this->json(200, Actor::collection($u->username, 'following'));
  }

  /**
   * 投稿（/ap/users/{name}/notes/{id}）
   * 公開・未収載以外は、署名したアクターが宛先かフォロワーの場合だけ返す
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function apnote(array $params): void {
    [$u, $note] = $this->noteOr404($params);
    $url = Notes::url($note);
    if ($this->wantsHtml()) {
      header('Location: '.Notes::htmlUrl($url));
      exit;
    }
    $this->json(200, Notes::toObject($note));
  }

  public function apnoteactivity(array $params): void {
    [$u, $note] = $this->noteOr404($params);
    $this->json(200, Notes::toCreate($note));
  }

  /**
   * NodeInfo（サーバーのソフトウェアの情報。他のサーバーが表示に使う）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function nodeinfo(array $params): void {
    $this->json(200, ['links' => [['rel' => 'http://nodeinfo.diaspora.software/ns/schema/2.0', 'href' => Fedi::base().'/nodeinfo/2.0']]],
                'application/json');
  }

  public function nodeinfoSchema(array $params): void {
    $users = 0;
    foreach (glob((Fedi::$userDir ?? ROOT.'/data/user/').'*.json') ?: [] as $f) {
      $d = json_decode((string)file_get_contents($f));
      if ($d instanceof \stdClass && can_federate($d)) $users++;
    }
    $this->json(200, [
      'version' => '2.0',
      'software' => ['name' => 'littlebeast', 'version' => '1.0'],
      'protocols' => ['activitypub'],
      'services' => ['inbound' => [], 'outbound' => ['atom1.0']],
      'openRegistrations' => AUTH_REGISTER_ENABLED,
      'usage' => ['users' => ['total' => $users], 'localPosts' => count(glob(Fedi::path('notes/').'*.json') ?: [])],
      'metadata' => ['nodeName' => SITEINFO['title']],
    ], 'application/json; profile="http://nodeinfo.diaspora.software/ns/schema/2.0#"');
  }

  ///////

  /** ローカルのアクター、無ければ404 */
  private function actorOr404(array $params): \stdClass {
    $u = Fedi::enabled() ? Fedi::localActor((string)($params['name'] ?? '')) : null;
    if ($u === null) $this->json(404, ['error' => '見つかりません']);
    return $u;
  }

  /** 見る事が出来る投稿、無ければ404 */
  private function noteOr404(array $params): array {
    $u = $this->actorOr404($params);
    $note = Notes::get((string)($params['id'] ?? ''));
    if (!$note || $note['author'] !== $u->username) $this->json(404, ['error' => '見つかりません']);
    if (!in_array($note['visibility'], ['public', 'unlisted'], true)) {
      $signer = (new Activitypub())->signer();
      $ok = $signer !== null && (in_array($signer, array_merge($note['to'], $note['cc']), true)
            || ($note['visibility'] === 'followers' && Actor::isFollowedBy($u->username, $signer)));
      if (!$ok) $this->json(404, ['error' => '見つかりません']);
    }
    return [$u, $note];
  }

  /** ブラウザからのアクセスか（ActivityPubのJSONを求めていない） */
  private function wantsHtml(): bool {
    $accept = (string)($_SERVER['HTTP_ACCEPT'] ?? '');
    return str_contains($accept, 'text/html') && !str_contains($accept, 'activity+json') && !str_contains($accept, 'ld+json');
  }

  /** ブログのアクターのresource（acct:actor@host又は/ap/actor） */
  private function isBlogResource(string $resource): bool {
    if ($resource === Fedi::blogActorUrl()) return true;
    return strtolower($resource) === strtolower('acct:'.FEDIINFO['actor'].'@'.Fedi::host());
  }

  private function json(int $code, array $data, string $type = 'application/activity+json'): never {
    $status = [200 => 'OK', 202 => 'Accepted', 400 => 'Bad Request', 401 => 'Unauthorized', 403 => 'Forbidden',
               404 => 'Not Found', 500 => 'Internal Server Error'][$code] ?? '';
    header("HTTP/1.1 {$code} {$status}");
    header("Content-Type: {$type}");
    echo json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
    exit;
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apactivity(array $params): void {
    $uuid = '';
    if (isset($params['uuid'])) $uuid = $params['uuid'];

    try {
      header('Content-Type: application/activity+json');
      $posts = $this->federatedPosts();
      $ap = new Activitypub($posts);
      $json = $ap->getActivity($uuid, $params['section'] ?? 'blog');
      if ($json === '') {
        header('HTTP/1.1 404 Not Found');
        echo json_encode(['error' => '見つかりません']);
        exit;
      }
      echo $json;
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apobject(array $params): void {
    try {
      header('Content-Type: application/activity+json');
      $ap = new Activitypub($this->federatedPosts());
      $json = $ap->getObject($params['uuid'] ?? '', $params['section'] ?? 'blog');
      if ($json === '') {
        header('HTTP/1.1 404 Not Found');
        echo json_encode(['error' => '見つかりません']);
        exit;
      }
      echo $json;
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * 投稿への返信のコレクション（/ap/objects/{uuid}/replies）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function apreplies(array $params): void {
    try {
      header('Content-Type: application/activity+json');
      $ap = new Activitypub($this->federatedPosts());
      $json = $ap->getReplies($params['uuid'] ?? '', $params['section'] ?? 'blog');
      if ($json === '') {
        header('HTTP/1.1 404 Not Found');
        echo json_encode(['error' => '見つかりません']);
        exit;
      }
      echo $json;
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apoutbox(array $params): void {
    try {
      header('Content-Type: application/activity+json');
      $posts = $this->federatedPosts();
      $ap = new Activitypub($posts);
      echo $ap->getOutbox();
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apfollowers(array $params): void {
    try {
      header('Content-Type: application/activity+json');
      $ap = new Activitypub();
      echo $ap->getFollowers();
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }

  /**
   * @param array $params パラメータ配列
   * @return void
   */
  public function apfollowing(array $params): void {
    try {
      header('Content-Type: application/activity+json');
      $ap = new Activitypub();
      echo $ap->getFollowing();
      exit;
    } catch (\Exception $e) {
      header('Content-Type: text/plain; charset=utf-8');
      echo 'フェディバースの作成に失敗: '.$e->getMessage();
      exit;
    }
  }
}