<?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\Auth;
use Std\Lib\Comments;
use Std\Lib\Template;

/**
 * 記事のコメントの投稿・いいね・削除（POST）と通知のページ
 */
class Comment extends BlogPost {
  use Mods;

  private ?\stdClass $user;

  public function __construct() {
    $this->user = (new Auth())->getLoggedInUser();
  }

  /**
   * コメントする（POST /comments）
   * thread：スレッド、parent：返信先のコメント、body：本文（Markdown）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function post(array $params): void {
    $user = $this->requireUser();
    $thread = (string)($_POST['thread'] ?? '');
    $parent = (string)($_POST['parent'] ?? '');
    $body = (string)($_POST['body'] ?? '');

    $title = $this->commentable($thread);
    if ($title === null) $this->notFound();

    if (!$this->csrfOk()) {
      $error = 'セッションの有効期限が切れました。もう一度送信して下さい。';
    } else {
      $res = Comments::addLocal($thread, $title, $user, $body, $parent === '' ? null : $parent, $this->postNote($thread));
      if ($res->isSuccess) $this->redirect('/'.$thread.'#c-'.$res->data['id']);
      $error = $res->message;
    }

    // 失敗：入力した内容を残して表示する
    $this->render('comment', 'コメント', [
      'error' => $error,
      'thread' => $thread,
      'title' => $title,
      'parent' => $parent,
      'body' => $body,
      'maxLength' => Comments::MAX_LENGTH,
    ]);
  }

  /**
   * いいね・いいねの取り消し（POST /comments/like）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function like(array $params): void {
    [$user, $thread, $id] = $this->target();
    $res = Comments::like($thread, $id, $user);
    if (!$res->isSuccess) $this->message($res->message, '/'.$thread.'#comments');
    $this->redirect('/'.$thread.'#c-'.$id);
  }

  /**
   * コメントを削除する（POST /comments/delete、本人又は管理者）
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function delete(array $params): void {
    [$user, $thread, $id] = $this->target();
    $res = Comments::delete($thread, $id, $user);
    if (!$res->isSuccess) $this->message($res->message, '/'.$thread.'#comments');
    $this->redirect('/'.$thread.'#comments');
  }

  /**
   * 通知（GET /notifications）。管理者には新しいコメント、全員には自分のコメントへの返信といいね
   *
   * @param array $params パラメータ配列
   * @return void
   */
  public function notifications(array $params): void {
    $user = $this->requireUser();
    $list = array_map(fn($n) => Comments::present($n), \Std\Lib\Notifications::list($user->username));
    \Std\Lib\Notifications::markRead($user->username);
    $this->render('notifications', '通知', ['list' => $list]);
  }

  //////

  /**
   * コメント出来る記事か（記事が存在し、このユーザーが読める）
   *
   * @param string $thread  スレッド（「blog/記事」等）
   * @return string|null  記事のタイトル、コメント出来なければnull
   */
  private function commentable(string $thread): ?string {
    if (!Comments::validThread($thread)) return null;
    $parts = explode('/', $thread);
    if (count($parts) !== 2 || !isset(blogs()[$parts[0]])) return null;
    foreach ($this->getPosts("/{$parts[0]}/", $this->user) as $post) {
      // 会員限定等で読めない記事にはコメント出来ない
      if ($post['slug'] === $parts[1]) return $post['preview'] === '未許可' ? null : (string)$post['title'];
    }
    return null;
  }

  /**
   * 連合するブログの記事のNote（Fediverseのロールを持つユーザーのコメントを、記事への返信として送る為）
   *
   * @param string $thread  スレッド
   * @return array|null  連合しない記事（勉強会、会員限定等）ならnull
   */
  private function postNote(string $thread): ?array {
    [$section, $slug] = array_pad(explode('/', $thread, 2), 2, '');
    if (!ACTIVITYPUB_ENABLED || !(blogs()[$section]['federate'] ?? false)) return null;
    foreach ($this->getPosts("/{$section}/", null) as $post) {
      if ($post['slug'] !== $slug) continue;
      $json = (new Activitypub([$post + ['section' => $section]]))->getObject((string)$post['uuid'], $section);
      return $json !== '' ? json_decode($json, true) : null;
    }
    return null;
  }

  /** いいね・削除の対象（ログイン、CSRF、記事を確認する） */
  private function target(): array {
    $user = $this->requireUser();
    $thread = (string)($_POST['thread'] ?? '');
    $id = (string)($_POST['id'] ?? '');
    if ($this->commentable($thread) === null) $this->notFound();
    if (!$this->csrfOk()) $this->message('セッションの有効期限が切れました。前のページに戻って、もう一度お試し下さい。', '/'.$thread.'#comments');
    return [$user, $thread, $id];
  }

  private function requireUser(): \stdClass {
    if ($this->user === null) $this->redirect('/login');
    return $this->user;
  }

  private function csrfOk(): bool {
    return is_string($_POST['csrf_token'] ?? null) && verify_csrf_token($_POST['csrf_token']);
  }

  private function redirect(string $to): never {
    header('Location: '.$to);
    exit;
  }

  private function notFound(): never {
    header('Location: /404');
    exit;
  }

  private function message(string $msg, string $back): never {
    $this->render('comment', 'コメント', ['error' => $msg, 'back' => $back]);
    exit;
  }

  private function render(string $view, string $title, array $vars): void {
    $tmpl = new Template('/');
    $tmpl->assign('pagetit', $title);
    $tmpl->assign('curPage', 'comments');
    $tmpl->assign('custCss', false);
    $tmpl->assign('menu', $this->getMenu());
    $tmpl->assign('description', SITEINFO['description']);
    $tmpl->assign('user', $this->user);
    // クッキーはテンプレートの出力の前に設定する
    $tmpl->assign('csrf', make_csrf_token());
    foreach ($vars as $k => $v) $tmpl->assign($k, $v);
    $tmpl->addCss('comments');
    $tmpl->render($view);
  }
}