// services/mam-api/src/routes/sequences.js
import express from 'express';
import pool    from '../db/pool.js';
import { getSignedUrlForObject } from '../s3/client.js';
import { requireAuth } from '../middleware/auth.js';

const router = express.Router();
router.use(requireAuth);

// ── 59.94 DF timecode helpers (for EDL export) ────────────────────────────────
const NOM  = 60;   // nominal integer fps
const DROP = 4;    // frames dropped per minute (except every 10th)
const FRAMES_PER_MIN   = NOM * 60 - DROP;         // 3596
const FRAMES_PER_10MIN = FRAMES_PER_MIN * 10 + DROP; // 35964
const FRAMES_PER_HOUR  = FRAMES_PER_10MIN * 6;    // 215784

function pad2(n) { return String(Math.floor(n)).padStart(2, '0'); }

function framesToTC(totalFrames) {
  const fc  = Math.max(0, Math.round(totalFrames));
  const h   = Math.floor(fc / FRAMES_PER_HOUR);
  let rem   = fc % FRAMES_PER_HOUR;
  const tm  = Math.floor(rem / FRAMES_PER_10MIN);
  rem       = rem % FRAMES_PER_10MIN;
  let m     = 0;
  if (rem >= DROP) {
    m   = Math.floor((rem - DROP) / FRAMES_PER_MIN) + 1;
    rem = (rem - DROP) % FRAMES_PER_MIN;
  }
  const M  = tm * 10 + m;
  const s  = Math.floor(rem / NOM);
  const ff = rem % NOM;
  return `${pad2(h)}:${pad2(M)}:${pad2(s)};${pad2(ff)}`;
}

function generateEDL(seqName, clips) {
  const lines = [`TITLE: ${seqName}`, ''];
  clips.forEach((c, i) => {
    const num    = String(i + 1).padStart(3, '0');
    const reel   = (c.filename || 'UNKNOWN')
      .replace(/\.[^.]+$/, '')   // strip extension
      .replace(/[^A-Za-z0-9_]/g, '_')
      .toUpperCase()
      .substring(0, 32)
      .padEnd(8);
    const srcIn  = framesToTC(c.source_in_frames);
    const srcOut = framesToTC(c.source_out_frames);
    const recIn  = framesToTC(c.timeline_in_frames);
    const recOut = framesToTC(c.timeline_out_frames);
    lines.push(`${num}  ${reel}  V  C  ${srcIn} ${srcOut} ${recIn} ${recOut}`);
  });
  return lines.join('\n');
}

// ── GET / – list sequences for a project ─────────────────────────────────────
router.get('/', async (req, res, next) => {
  try {
    const { project_id } = req.query;
    if (!project_id) return res.status(400).json({ error: 'project_id is required' });
    const r = await pool.query(
      `SELECT * FROM sequences WHERE project_id = $1 ORDER BY updated_at DESC`,
      [project_id]
    );
    res.json(r.rows);
  } catch (e) { next(e); }
});

// ── POST / – create sequence ──────────────────────────────────────────────────
router.post('/', async (req, res, next) => {
  try {
    const {
      project_id,
      name       = 'Sequence 1',
      frame_rate = 59.94,
      width      = 1920,
      height     = 1080,
    } = req.body;
    if (!project_id) return res.status(400).json({ error: 'project_id is required' });
    const r = await pool.query(
      `INSERT INTO sequences (project_id, name, frame_rate, width, height)
       VALUES ($1, $2, $3, $4, $5) RETURNING *`,
      [project_id, name, frame_rate, width, height]
    );
    res.status(201).json(r.rows[0]);
  } catch (e) { next(e); }
});

// ── GET /:id – sequence + all clips joined with asset data ───────────────────
router.get('/:id', async (req, res, next) => {
  try {
    const seqR = await pool.query(
      `SELECT * FROM sequences WHERE id = $1`,
      [req.params.id]
    );
    if (!seqR.rows.length) return res.status(404).json({ error: 'Sequence not found' });

    const clipsR = await pool.query(
      `SELECT sc.*,
              a.display_name, a.filename, a.fps, a.duration_ms,
              a.proxy_s3_key, a.thumbnail_s3_key
       FROM sequence_clips sc
       JOIN assets a ON a.id = sc.asset_id
       WHERE sc.sequence_id = $1
       ORDER BY sc.track, sc.timeline_in_frames`,
      [req.params.id]
    );

    // Attach signed stream URLs (best-effort; missing proxy → streamUrl: null)
    const clips = await Promise.all(
      clipsR.rows.map(async (clip) => {
        let streamUrl = null;
        if (clip.proxy_s3_key) {
          try { streamUrl = await getSignedUrlForObject(clip.proxy_s3_key); } catch (_) {}
        }
        return { ...clip, streamUrl };
      })
    );

    res.json({ ...seqR.rows[0], clips });
  } catch (e) { next(e); }
});

// ── PUT /:id – update sequence metadata ──────────────────────────────────────
router.put('/:id', async (req, res, next) => {
  try {
    const { name, frame_rate, width, height } = req.body;
    const updates = [];
    const params  = [];
    let   n       = 1;
    if (name       !== undefined) { updates.push(`name = $${n++}`);       params.push(name); }
    if (frame_rate !== undefined) { updates.push(`frame_rate = $${n++}`); params.push(frame_rate); }
    if (width      !== undefined) { updates.push(`width = $${n++}`);      params.push(width); }
    if (height     !== undefined) { updates.push(`height = $${n++}`);     params.push(height); }
    if (!updates.length) return res.status(400).json({ error: 'No fields to update' });
    updates.push('updated_at = NOW()');
    params.push(req.params.id);
    const r = await pool.query(
      `UPDATE sequences SET ${updates.join(', ')} WHERE id = $${n} RETURNING *`,
      params
    );
    if (!r.rows.length) return res.status(404).json({ error: 'Sequence not found' });
    res.json(r.rows[0]);
  } catch (e) { next(e); }
});

// ── DELETE /:id ───────────────────────────────────────────────────────────────
router.delete('/:id', async (req, res, next) => {
  try {
    await pool.query(`DELETE FROM sequences WHERE id = $1`, [req.params.id]);
    res.json({ ok: true });
  } catch (e) { next(e); }
});

// ── PUT /:id/clips – full replace of clip array (single transaction) ──────────
router.put('/:id/clips', async (req, res, next) => {
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await client.query(
      `DELETE FROM sequence_clips WHERE sequence_id = $1`,
      [req.params.id]
    );
    const clips = Array.isArray(req.body) ? req.body : [];
    for (const c of clips) {
      await client.query(
        `INSERT INTO sequence_clips
           (sequence_id, asset_id, track,
            timeline_in_frames, timeline_out_frames,
            source_in_frames,   source_out_frames)
         VALUES ($1, $2, $3, $4, $5, $6, $7)`,
        [
          req.params.id, c.asset_id, c.track,
          c.timeline_in_frames, c.timeline_out_frames,
          c.source_in_frames,   c.source_out_frames,
        ]
      );
    }
    await client.query(
      `UPDATE sequences SET updated_at = NOW() WHERE id = $1`,
      [req.params.id]
    );
    await client.query('COMMIT');
    res.json({ ok: true, count: clips.length });
  } catch (e) {
    await client.query('ROLLBACK');
    next(e);
  } finally {
    client.release();
  }
});

// ── POST /:id/export/edl – download CMX3600 EDL ──────────────────────────────
router.post('/:id/export/edl', async (req, res, next) => {
  try {
    const seqR = await pool.query(`SELECT * FROM sequences WHERE id = $1`, [req.params.id]);
    if (!seqR.rows.length) return res.status(404).json({ error: 'Sequence not found' });
    const seq = seqR.rows[0];

    // Export V1 clips only (primary video track) sorted by position
    const clipsR = await pool.query(
      `SELECT sc.*, a.filename
       FROM sequence_clips sc
       JOIN assets a ON a.id = sc.asset_id
       WHERE sc.sequence_id = $1 AND sc.track = 0
       ORDER BY sc.timeline_in_frames`,
      [req.params.id]
    );

    const edl      = generateEDL(seq.name, clipsR.rows);
    const filename = `${seq.name.replace(/[^a-z0-9]/gi, '_')}.edl`;
    res.setHeader('Content-Type',        'text/plain; charset=utf-8');
    res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
    res.send(edl);
  } catch (e) { next(e); }
});

export default router;