/**
 * Scheduler — release planning (premium #3).
 *
 * Scheduled posts have status 'scheduled' + publish_at (future). A lightweight
 * timer flips them to 'published' once publish_at is reached. This means public
 * queries (status='published') need NO changes — a scheduled post simply isn't
 * 'published' yet and therefore invisible until that moment.
 */

import db, { NU_ISO } from '../config/database.js';
import HtmlSanitizerService from './HtmlSanitizerService.js';
import ActivityPubService from './ActivityPubService.js';

export function flipScheduledPosts() {
  try {
    const due = db.prepare(`
      SELECT p.id, p.site_id, p.slug, p.title, p.content, p.cover_image_url, p.cover_video_url, p.cover_alt, p.language, p.fan_only, p.nsfw, p.content_warning, p.poll_json,
             p.published_at, p.publish_at, p.created_at, u.username
      FROM posts p JOIN users u ON u.id = p.author_id
      WHERE p.status = 'scheduled' AND p.publish_at IS NOT NULL AND datetime(p.publish_at) <= datetime('now')
    `).all();
    if (!due.length) return 0;
    const upd = db.prepare(
      `UPDATE posts SET status = 'published', published_at = COALESCE(published_at, publish_at, ${NU_ISO}) WHERE id = ?`
    );
    const ftsDel = db.prepare('DELETE FROM posts_fts WHERE post_id = ?');
    const fts = db.prepare('INSERT INTO posts_fts(content, title, author, post_id) VALUES (?, ?, ?, ?)');
    const siteStmt = db.prepare('SELECT * FROM sites WHERE id = ?');
    for (const p of due) {
      upd.run(p.id);
      // Delete-before-insert so a re-scheduled (previously published) post doesn't
      // get a duplicate FTS row → duplicate search hits.
      try { ftsDel.run(p.id); fts.run(HtmlSanitizerService.toPlainText(p.content || ''), p.title || '', p.username || '', p.id); } catch { /* FTS failure is non-fatal */ }
      // ActivityPub: federate the now-published post to followers (fan_only → followers-only).
      try {
        const site = siteStmt.get(p.site_id);
        if (site) {
          ActivityPubService.deliverCreate(site, {
            id: p.id, slug: p.slug, title: p.title || p.slug,
            content: p.content, cover_image_url: p.cover_image_url || null, cover_video_url: p.cover_video_url || null, cover_alt: p.cover_alt, language: p.language,
            published_at: p.published_at || p.publish_at, created_at: p.created_at, fan_only: p.fan_only, nsfw: p.nsfw, content_warning: p.content_warning, poll_json: p.poll_json,
          }).catch(() => { /* best-effort */ });
        }
      } catch { /* non-fatal */ }
    }
    return due.length;
  } catch { return 0; }
}

// Close hosted polls whose endTime has passed: mark them closed (once) and push the final
// tally + closed state to followers as Update(Question). The `closed` flag in poll_json
// guards against re-sending — a poll is only processed on the tick that crosses its endTime.
export function closeExpiredPolls() {
  try {
    const due = db.prepare(`
      SELECT id, poll_json FROM posts
      WHERE poll_json IS NOT NULL
        AND status = 'published'
        AND json_extract(poll_json, '$.endTime') IS NOT NULL
        AND IFNULL(json_extract(poll_json, '$.closed'), 0) = 0
        AND datetime(json_extract(poll_json, '$.endTime')) <= datetime('now')
    `).all();
    if (!due.length) return 0;
    const upd = db.prepare('UPDATE posts SET poll_json = ? WHERE id = ?');
    for (const p of due) {
      let d; try { d = JSON.parse(p.poll_json); } catch { continue; }
      d.closed = true;
      upd.run(JSON.stringify(d), p.id);
      ActivityPubService.deliverPollUpdate(p.id).catch(() => { /* best-effort */ });
    }
    return due.length;
  } catch { return 0; }
}

let _timer = null;
function tick() { flipScheduledPosts(); closeExpiredPolls(); }
export function startScheduler() {
  tick();                               // run immediately on boot
  if (_timer) return;
  _timer = setInterval(tick, 60 * 1000); // every minute
  if (_timer.unref) _timer.unref();
}