// EPG binder. Run AFTER build-iptv.mjs (refresh.ts does both + grab). It:
//   1. matches each playlist channel to an iptv-org/epg source:
//        - real tvg-id  -> epg channel with the same BASE id (ignoring @feed suffix)
//        - Pluto channels -> /plu-<id>/ in the URL IS epg's pluto.tv site_id, so we
//          synthesise a tvg-id even when upstream left it blank
//   2. rewrites the playlist's tvg-id to a canonical id + adds the url-tvg header
//   3. writes /tmp/iptv-org-build/custom.channels.xml for `grab`
// Samsung & Tubi have no epg site upstream, so they only bind if a real tvg-id matches.
import { readFileSync, writeFileSync, readdirSync, existsSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import path from 'node:path';

const HERE = path.dirname(fileURLToPath(import.meta.url));
const M3U = path.join(HERE, 'iptv.m3u');
const SITES = '/tmp/iptv-org-build/epg/sites';
const OUTXML = '/tmp/iptv-org-build/custom.channels.xml';
// Public URL where guide.xml is served — must match deploy.ts's bucket path.
const EPG_URL = 'https://chillidonut.com/junk/iptv/guide.xml';

if (!existsSync(SITES)) {
  process.stderr.write(`epg clone not found at ${SITES}\n` +
    'Run: git clone --depth 1 https://github.com/iptv-org/epg.git /tmp/iptv-org-build/epg  (or use refresh.ts)\n');
  process.exit(1);
}

const baseId = (x) => (x || '').split('@')[0].trim();
const cleanName = (n) => n.replace(/\s*\(\d+p\)|\s*\[[^\]]*\]|\s*\([^)]*\)\s*$/g, '').trim() || n;

// ---------- index epg channel mappings ----------
const chanRe = /<channel\s+([^>]*?)>([^<]*)<\/channel>/g;
const attrRe = /([\w]+)="([^"]*)"/g;
const baseIdx = new Map();   // base(xmltv_id) -> {site, site_id, lang}
const plutoIdx = new Map();  // pluto site_id (hex) -> {xmltv_id, lang}
for (const site of readdirSync(SITES)) {
  let dir;
  try { dir = readdirSync(path.join(SITES, site)); } catch { continue; }
  for (const f of dir) {
    if (!f.endsWith('.channels.xml')) continue;
    for (const c of readFileSync(path.join(SITES, site, f), 'utf8').matchAll(chanRe)) {
      const a = {};
      for (const m of c[1].matchAll(attrRe)) a[m[1]] = m[2];
      if (site === 'pluto.tv' && a.site_id) plutoIdx.set(a.site_id, { xmltv_id: a.xmltv_id, lang: a.lang || 'en' });
      const b = baseId(a.xmltv_id);
      if (b && a.site_id && !baseIdx.has(b)) baseIdx.set(b, { site: a.site, site_id: a.site_id, lang: a.lang || 'en' });
    }
  }
}

// ---------- resolve each playlist channel ----------
function resolve(url, tvgid, name) {
  const pm = url.match(/plu-([0-9a-f]{16,})/i);
  if (pm && plutoIdx.has(pm[1])) {
    const e = plutoIdx.get(pm[1]);
    return { id: baseId(e.xmltv_id) || `pluto-${pm[1]}`, site: 'pluto.tv', site_id: pm[1], lang: e.lang, name: cleanName(name) };
  }
  const b = baseId(tvgid);
  if (b && baseIdx.has(b)) {
    const e = baseIdx.get(b);
    return { id: b, site: e.site, site_id: e.site_id, lang: e.lang, name: cleanName(name) };
  }
  return { id: b }; // keep base id if any (no grab source), else ''
}

// ---------- rewrite playlist + collect channels ----------
const lines = readFileSync(M3U, 'utf8').split('\n');
const channels = new Map(); // site|site_id -> row
const seenIds = new Set();   // one grab source (and one guide <channel>) per id
let plutoMatched = 0, idMatched = 0;
const bySection = {};
let section = '';
for (let i = 0; i < lines.length; i++) {
  const l = lines[i];
  if (l.startsWith('# SECTION:')) section = l.replace(/.*SECTION:\s*/, '').replace(/\s{2,}.*/, '');
  if (l === '#EXTM3U') { lines[i] = `#EXTM3U url-tvg="${EPG_URL}"`; continue; }
  if (!l.startsWith('#EXTINF')) continue;
  let url = '';
  for (let j = i + 1; j < lines.length; j++) {
    const t = lines[j].trim();
    if (!t || t.startsWith('#')) { if (t.startsWith('#EXTINF')) break; continue; }
    url = t; break;
  }
  if (!url) continue;
  const tvgid = (l.match(/tvg-id="([^"]*)"/) || [])[1] || '';
  const name = l.slice(l.indexOf(',') + 1);
  const r = resolve(url, tvgid, name);
  lines[i] = l.replace(/tvg-id="[^"]*"/, `tvg-id="${r.id || ''}"`);
  bySection[section] = bySection[section] || { have: 0, total: 0 };
  bySection[section].total++;
  if (r.site && r.site_id) {
    bySection[section].have++;
    if (!seenIds.has(r.id)) {
      seenIds.add(r.id);
      if (r.site === 'pluto.tv') plutoMatched++; else idMatched++;
      channels.set(`${r.site}|${r.site_id}`, r);
    }
  }
}
writeFileSync(M3U, lines.join('\n'));

// ---------- write channels.xml ----------
const esc = (s) => String(s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
const rows = [...channels.values()].sort((a, b) => a.id.localeCompare(b.id));
const xml = ['<?xml version="1.0" encoding="UTF-8"?>', '<channels>'];
for (const r of rows)
  xml.push(`  <channel site="${esc(r.site)}" lang="${esc(r.lang)}" xmltv_id="${esc(r.id)}" site_id="${esc(r.site_id)}">${esc(r.name)}</channel>`);
xml.push('</channels>');
writeFileSync(OUTXML, xml.join('\n') + '\n');

// ---------- report ----------
process.stderr.write(`EPG url-tvg: ${EPG_URL}\n`);
process.stderr.write(`grab channels: ${rows.length}  (pluto: ${plutoMatched}, by-id: ${idMatched})  -> ${OUTXML}\n\n`);
process.stderr.write('EPG-bound channels per section:\n');
for (const [s, v] of Object.entries(bySection).sort())
  process.stderr.write(`  ${String(v.have).padStart(4)} / ${String(v.total).padEnd(4)}  ${s}\n`);