<?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 Std\Lib\Gitler;

use Std\Lib\Fedi\Html;
use Std\Lib\Notifications;

/**
 * Gitlerの通知（サイトの「通知」とメール）
 *
 * リポジトリのウォッチ（gitler/watch.json：ユーザー名 => watching、participating、ignoring）：
 *   watching  新しいイシューと全部のイシューの動き（所有者と共同作業者の既定）
 *   participating  通知を受け取るイシューだけ（他の人の既定）
 *   ignoring  何も受け取らない
 * イシュー毎の受け取り（subscribers）：作った人、コメントした人、担当者、メンションされた人。止める事も出来る。
 * メールはKeysの設定（既定は受け取る）で、cronのnotifyが送る。自分の操作は通知しない。
 */
final class Notify {
  public const WATCHING = 'watching';
  public const PARTICIPATING = 'participating';
  public const IGNORING = 'ignoring';
  /** 「@ユーザー」（「@user@host」と「@所有者.名前」は除く） */
  public const MENTION_RE = '/(?<![\w@\/&.])@([A-Za-z0-9]+)(?![\w@]|\.\w)/';

  //////// ウォッチ

  public static function watchState(string $owner, string $name, string $user, ?array $meta = null): string {
    $w = self::watchList($owner, $name)[$user] ?? null;
    if (in_array($w, [self::WATCHING, self::PARTICIPATING, self::IGNORING], true)) return $w;
    $meta ??= Gitler::meta($owner, $name);
    return $user === $owner || isset($meta['collaborators'][$user]) ? self::WATCHING : self::PARTICIPATING;
  }

  public static function setWatch(string $owner, string $name, string $user, string $state): void {
    if (!in_array($state, [self::WATCHING, self::PARTICIPATING, self::IGNORING], true)) return;
    $repo = Gitler::open($owner, $name);
    $file = $repo->path.'/gitler/watch.json';
    $repo->mkdir(dirname($file));
    $lock = @fopen($file.'.lock', 'c');
    if ($lock) flock($lock, LOCK_EX);
    try {
      $list = self::watchList($owner, $name);
      $list[$user] = $state;
      $repo->writeFile($file, (string)json_encode($list, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
    } finally {
      if ($lock) {
        flock($lock, LOCK_UN);
        fclose($lock);
      }
    }
  }

  /** ウォッチしている人（既定の所有者と共同作業者を含む） */
  public static function watchers(string $owner, string $name, array $meta): array {
    $out = [];
    foreach (array_unique(array_merge([$owner], array_map('strval', array_keys($meta['collaborators'])), array_keys(self::watchList($owner, $name)))) as $u) {
      if (self::watchState($owner, $name, (string)$u, $meta) === self::WATCHING) $out[] = (string)$u;
    }
    return $out;
  }

  //////// イシュー

  /** Markdownの本文の「@ユーザー」（コードの中は除く） */
  public static function mentions(string $text): array {
    $text = (string)preg_replace(['/^(```|~~~).*?^\1/ms', '/`[^`\n]*`/'], '', $text);
    preg_match_all(self::MENTION_RE, $text, $m);
    return array_values(array_unique($m[1]));
  }

  public static function issueOpened(string $owner, string $name, array $meta, Issues $db, array $issue): void {
    $mentioned = self::mentioned($owner, $name, $db, $issue['number'], $issue['body'], !empty($issue['html']));
    $to = array_fill_keys(self::watchers($owner, $name, $meta), 'opened') + array_fill_keys($issue['assignees'], 'assigned');
    foreach ($mentioned as $u) $to[$u] = 'mention';
    self::send($owner, $name, $meta, $db->get($issue['number']) ?? $issue, $issue['author'], $to, $issue['body'], !empty($issue['html']), '');
  }

  public static function commented(string $owner, string $name, array $meta, Issues $db, array $issue, array $c): void {
    $mentioned = self::mentioned($owner, $name, $db, $issue['number'], $c['body'], !empty($c['html']));
    $issue = $db->get($issue['number']) ?? $issue;
    $to = array_fill_keys(array_merge(self::watchers($owner, $name, $meta), self::subscribed($issue)), 'comment');
    foreach ($mentioned as $u) $to[$u] = 'mention';
    self::send($owner, $name, $meta, $issue, $c['author'], $to, $c['body'], !empty($c['html']), '#c'.$c['id']);
  }

  /** 閉じた・開き直した（$byはコミット等も） */
  public static function stateChanged(string $owner, string $name, array $meta, array $issue, array $by): void {
    $type = $issue['state'] === 'closed' ? (isset($by['commit']) ? 'closedByCommit' : 'closed') : 'reopened';
    $to = array_fill_keys(array_merge(self::watchers($owner, $name, $meta), self::subscribed($issue)), $type);
    self::send($owner, $name, $meta, $issue, $by, $to, '', false, '');
  }

  /** プルリクエストをマージした */
  public static function merged(string $owner, string $name, array $meta, array $issue, array $by): void {
    $to = array_fill_keys(array_merge(self::watchers($owner, $name, $meta), self::subscribed($issue)), 'merged');
    self::send($owner, $name, $meta, $issue, $by, $to, '', false, '');
  }

  /** プルリクエストのレビュー（state：approved、changes、commented） */
  public static function reviewed(string $owner, string $name, array $meta, Issues $db, array $issue, array $review): void {
    $mentioned = self::mentioned($owner, $name, $db, $issue['number'], $review['body'], false);
    $issue = $db->get($issue['number']) ?? $issue;
    $to = array_fill_keys(array_merge(self::watchers($owner, $name, $meta), self::subscribed($issue)), $review['state']);
    foreach ($mentioned as $u) $to[$u] = 'mention';
    self::send($owner, $name, $meta, $issue, $review['author'], $to, $review['body'], false, '#r'.$review['id']);
  }

  /** 担当者に追加した */
  public static function assigned(string $owner, string $name, array $meta, array $issue, array $users, array $by): void {
    self::send($owner, $name, $meta, $issue, $by, array_fill_keys($users, 'assigned'), '', false, '');
  }

  //////// 送る

  /**
   * 通知を追加し、メールを待ち行列に入れる（SSHのプッシュではリポジトリに溜める）
   *
   * @param array|null $mail  to、subject、body、name
   */
  public static function deliver(string $user, array $record, ?array $mail): void {
    if ($user === '' || empty($record)) return;
    Notifications::add($user, $record);
    if (is_array($mail)) Notifications::queueMail((string)$mail['to'], (string)$mail['subject'], (string)$mail['body'], (string)($mail['name'] ?? ''));
  }

  /**
   * @param array $to  ユーザー名 => 種類（opened、comment、mention、closed、closedByCommit、reopened、assigned、merged、
   *                   approved・changes・commented（レビュー））
   * @param string $anchor  コメントの「#c5」等
   */
  private static function send(string $owner, string $name, array $meta, array $issue, array $by, array $to, string $body, bool $html, string $anchor): void {
    if (empty($to) || $meta['archived']) return;
    $n = $issue['number'];
    $repoName = "{$owner}/{$name}";
    $title = "{$repoName}#{$n}「{$issue['title']}」";
    $commit = isset($by['commit']) ? substr((string)$by['commit'], 0, 7) : '';
    $kind = isset($issue['pull']) ? 'プルリクエスト' : 'イシュー';
    $path = '/gitler/'.$owner.'/'.rawurlencode($name).(isset($issue['pull']) ? '/pulls/' : '/issues/').$n.$anchor;
    $excerpt = $body !== '' ? Html::text($html ? $body : Issues::render($body, '/gitler/'.$owner.'/'.rawurlencode($name).'/issues')) : '';
    // Markdownの整形の空白を除く
    $excerpt = trim((string)preg_replace(['/[ \t]*\n[ \t]*/', '/\n{3,}/'], ["\n", "\n\n"], $excerpt));
    $from = isset($by['user']) ? ['username' => (string)$by['user']] : (isset($by['actor']) ? $by : ['name' => (string)($by['name'] ?? '')]);
    $fromName = Federation::authorName($by);
    $base = rtrim((string)(SITEINFO['url'] ?? ''), '/') ?: \Std\Lib\Fedi\Fedi::base();
    foreach ($to as $user => $type) {
      $user = (string)$user;
      if ($user === ($by['user'] ?? null)) continue;
      // 止めた人（メンションと担当は届ける）、無視している人、読めない人には送らない
      if (($issue['subscribers'][$user] ?? null) === false && !in_array($type, ['mention', 'assigned'], true)) continue;
      if (self::watchState($owner, $name, $user, $meta) === self::IGNORING) continue;
      $u = Gitler::user($user);
      if ($u === null || Gitler::access($u, $owner, $name) < Gitler::READ) continue;
      $label = match ($type) {
        'opened' => "が{$repoName}に{$kind}#{$n}「{$issue['title']}」を作りました",
        'merged' => "が{$title}をマージしました",
        'approved' => "が{$title}を承認しました",
        'changes' => "が{$title}に変更を依頼しました",
        'commented' => "が{$title}をレビューしました",
        'comment' => "が{$title}にコメントしました",
        'mention' => "が{$title}であなたをメンションしました",
        'closed' => "が{$title}を閉じました",
        'closedByCommit' => "のコミット{$commit}が{$title}を閉じました",
        'reopened' => "が{$title}を開き直しました",
        'assigned' => "が{$title}の担当者にあなたを追加しました",
        default => '',
      };
      $record = ['type' => 'gitler', 'from' => $from, 'label' => $label, 'page' => $path, 'excerpt' => mb_strimwidth((string)preg_replace('/\s+/u', ' ', $excerpt), 0, 160, '…')];
      $mail = null;
      if (($u->email ?? '') !== '' && Keys::load($user)['email']) {
        $mail = ['to' => (string)$u->email, 'name' => $user, 'subject' => "[{$repoName}] {$issue['title']} (#{$n})",
                 'body' => $fromName.$label."\n\n".($excerpt !== '' ? mb_strimwidth($excerpt, 0, 4000, '…')."\n\n" : '').$base.$path."\n\n--\n"
                          ."このリポジトリの通知（ウォッチ）：{$base}/gitler/{$owner}/".rawurlencode($name)."\nメールの通知を止める：{$base}/gitler/-/keys\n"];
      }
      if (Gitler::$deferred) {
        Gitler::defer($owner, $name, ['kind' => 'notify', 'user' => $user, 'record' => $record, 'mail' => $mail]);
      } else {
        self::deliver($user, $record, $mail);
      }
    }
  }

  /** 本文でメンションされた、リポジトリを読めるユーザー（通知を受け取る様にする） */
  private static function mentioned(string $owner, string $name, Issues $db, int $n, string $body, bool $html): array {
    $out = [];
    foreach (self::mentions($html ? Html::text($body) : $body) as $u) {
      $user = Gitler::user($u);
      if ($user !== null && Gitler::access($user, $owner, $name) >= Gitler::READ) $out[] = (string)$user->username;
    }
    if (!empty($out)) $db->subscribe($n, $out, true);
    return $out;
  }

  /** イシューの通知を受け取る人 */
  private static function subscribed(array $issue): array {
    return array_map('strval', array_keys(array_filter($issue['subscribers'] ?? [], fn($on) => $on === true)));
  }

  private static function watchList(string $owner, string $name): array {
    $j = json_decode((string)@file_get_contents(Gitler::path($owner, $name).'/gitler/watch.json'), true);
    return is_array($j) ? $j : [];
  }
}