// routes/hls.js
const express = require('express');
const path = require('path');
const fs = require('fs');
const db = require('../db/knex');
const config = require('../api_v1/config');
const { getUserAccess, filterReadableSources } = require('../api_v1/userAccess');
const { startJob, getJob } = require('../helpers/hlsManager');

const router = express.Router();

const HLS_BASE = path.resolve(process.env.HLS_BASE || path.join(process.cwd(), 'hls_output'));
const PUBLIC_BASE_URL = config.BASE_URL || null;

const PUBLIC_ROOT = path.resolve(__dirname, '..', 'public');
const PHOTOS_ROOT = path.join(PUBLIC_ROOT, 'photos');

function safeJoin(base, ...parts) {
  const resolvedBase = path.resolve(base);
  const resolved = path.resolve(base, ...parts);
  const isInsideBase = resolved === resolvedBase || resolved.startsWith(`${resolvedBase}${path.sep}`);
  if (!isInsideBase) throw new Error(`Path non sicuro: ${resolved}`);
  return resolved;
}

// POST /hls/start
// body: { photoId } OR { inputPath } + outDir, callbackUrl, segmentsNeeded
router.post('/start', async (req, res) => {
  try {
    const caller = String(req.user?.name ?? '').trim();
    if (!caller) return res.status(401).json({ error: 'Unauthorized' });

    const { photoId, inputPath: providedPath, outDir = 'fabiocast', callbackUrl, segmentsNeeded = 3 } = req.body || {};

    if (!callbackUrl) return res.status(400).json({ error: 'Missing callbackUrl' });

    let inputPath = providedPath;

    if (photoId && !providedPath) {
      const row = await db('photos').where({ id: photoId }).first();
      if (!row) return res.status(404).json({ error: 'Photo not found' });

      const access = getUserAccess(caller);
      if (!access) return res.status(403).json({ error: 'User not configured' });

      const allowed = filterReadableSources(access.name, row.user);
      if (!allowed || allowed.length === 0) return res.status(403).json({ error: 'Access denied to this photo' });

      if (row.path && typeof row.path === 'string' && row.path.trim()) {
        const rel = row.path.replace(/^\/+/, '');
        inputPath = safeJoin(PUBLIC_ROOT, rel);
      } else {
        inputPath = safeJoin(PHOTOS_ROOT, row.user, 'original', row.cartella || '', row.name);
      }
    }

    if (!inputPath) return res.status(400).json({ error: 'Missing inputPath or photoId' });

    // outDir sotto HLS_BASE
    const safeOut = String(outDir || 'fabiocast').replace(/[^a-zA-Z0-9_\-\/]/g, '_');
    const jobParentDir = path.isAbsolute(safeOut) ? path.join(safeOut) : path.join(HLS_BASE, safeOut);

    const jobId = startJob({
      inputPath,
      outDir: jobParentDir,
      segmentsNeeded,
      callbackUrl,
      publicBaseUrl: PUBLIC_BASE_URL
    });

    return res.status(202).json({ jobId, outDir: jobParentDir, message: 'Transcode started' });
  } catch (err) {
    console.error('Error /hls/start:', err);
    return res.status(500).json({ error: err.message });
  }
});

// GET /hls/status/:jobId
router.get('/status/:jobId', (req, res) => {
  const job = getJob(req.params.jobId);
  if (!job) return res.status(404).json({ error: 'Job not found' });
  return res.json({
    jobId: job.jobId,
    inputPath: job.inputPath,
    outDir: job.outDir,
    notified: job.notified,
    useRkmpp: job.useRkmpp,
    startTime: job.startTime
  });
});

// GET /hls/url/:jobId -> restituisce public URL completo se possibile
router.get('/url/:jobId', (req, res) => {
  const job = getJob(req.params.jobId);
  if (!job) return res.status(404).json({ error: 'Job not found' });

  const masterPath = path.join(job.outDir, 'master.m3u8');
  if (!fs.existsSync(masterPath)) return res.status(404).json({ error: 'Playlist not yet available' });

  // costruisci la parte relativa rispetto a HLS_BASE (evita duplicazioni come /hls/hls_output/...)
  const base = PUBLIC_BASE_URL || `${req.protocol}://${req.get('host')}`;
  const rel = path.relative(HLS_BASE, masterPath).split(path.sep).join('/');
  const publicUrl = `${base.replace(/\/$/, '')}/hls/${rel}`;

  return res.json({ jobId: job.jobId, master_m3u8: publicUrl, status: job.notified ? 'ready' : 'processing' });
});

module.exports = router;