const express = require('express');
const router = express.Router();
const { query } = require('../config/db');

// GET /api/series — список серий
router.get('/', async (req, res) => {
  try {
    const { rows } = await query(
      `SELECT s.*,
        (SELECT COUNT(*) FROM articles a
         WHERE a.id::text = ANY(SELECT jsonb_array_elements_text(s.article_ids))
           AND a.status='published') as articles_count
       FROM series s ORDER BY sort_order ASC, created_at ASC`
    );
    res.json(rows);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// GET /api/series/:slug — серия со статьями
router.get('/:slug', async (req, res) => {
  try {
    const { rows: sRows } = await query(`SELECT * FROM series WHERE slug=$1`, [req.params.slug]);
    if (!sRows.length) return res.status(404).json({ error: 'Not found' });
    const series = sRows[0];

    const ids = (series.article_ids || []).map(Number).filter(Boolean);
    let articles = [];
    if (ids.length) {
      const { rows: aRows } = await query(
        `SELECT id, slug, title, excerpt, cover_url, tags, reading_time, published_at
         FROM articles WHERE id = ANY($1::int[]) AND status='published'
         ORDER BY array_position($1::int[], id) ASC`,
        [ids]
      );
      articles = aRows;
    }
    res.json({ ...series, articles });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// POST /api/series — создать
router.post('/', async (req, res) => {
  try {
    const { slug, title, intro, icon, color, article_ids = [], is_featured, sort_order } = req.body;
    if (!slug || !title) return res.status(400).json({ error: 'slug and title required' });
    const { rows } = await query(
      `INSERT INTO series (slug, title, intro, icon, color, article_ids, is_featured, sort_order)
       VALUES ($1,$2,$3,$4,$5,$6,$7,$8) RETURNING *`,
      [slug, title, intro || null, icon || null, color || 'emerald',
       JSON.stringify(article_ids), !!is_featured, sort_order || 0]
    );
    res.json(rows[0]);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// PATCH /api/series/:id
router.patch('/:id', async (req, res) => {
  try {
    const { title, intro, icon, color, article_ids, is_featured, sort_order } = req.body;
    const { rows } = await query(
      `UPDATE series SET
        title=COALESCE($1,title),
        intro=COALESCE($2,intro),
        icon=COALESCE($3,icon),
        color=COALESCE($4,color),
        article_ids=COALESCE($5::jsonb,article_ids),
        is_featured=COALESCE($6,is_featured),
        sort_order=COALESCE($7,sort_order),
        updated_at=NOW()
       WHERE id=$8 RETURNING *`,
      [title, intro, icon, color,
       article_ids !== undefined ? JSON.stringify(article_ids) : null,
       is_featured, sort_order, req.params.id]
    );
    if (!rows.length) return res.status(404).json({ error: 'Not found' });
    res.json(rows[0]);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// DELETE /api/series/:id
router.delete('/:id', async (req, res) => {
  try {
    await query(`DELETE FROM series WHERE id=$1`, [req.params.id]);
    res.json({ ok: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

module.exports = router;