// Military aircraft (REAL) — the free, keyless adsb.lol /v2/mil feed via
// proxy/mil. This is the unfiltered military traffic OpenSky/FR24 hide (C-17
// Reach flights, tankers, the Area 51 "Janet" shuttle, etc.) — the OSINT prize.
//
// BillboardCollection primitive like the civilian aircraft layer, but a distinct
// red so it never blends in. Live-only (no history feed for this), polled every
// minute (the feed is free/unmetered; a 60s server cache coalesces callers).

export default function create(ctx) {
  const { viewer, CONFIG, lib, ui, Cesium } = ctx;
  const A = CONFIG.adsbx;

  const bc = viewer.scene.primitives.add(new Cesium.BillboardCollection());
  const glyph = lib.aircraftGlyph(); // shared triangle, tinted per-billboard

  let enabled = true;
  let isLive = true;
  let inFlight = false;
  let timer = null;
  let delay = A.pollMs;

  ui.addLayer('military', 'Military (adsb.lol)', true, (on) => {
    enabled = on;
    bc.show = on && isLive;
    if (on && isLive) kick();
  });
  ui.setStatus('military', 'loading…', 'warn');

  // Transponder emergency codes → the highlight label.
  const EMERG = { '7500': 'HIJACK', '7600': 'RADIO FAIL', '7700': 'EMERGENCY' };

  function canPoll() { return enabled && isLive && !document.hidden; }
  function schedule(ms) { if (timer) clearTimeout(timer); timer = setTimeout(tick, ms); }
  function kick() { if (!canPoll() || timer || inFlight) return; schedule(0); }

  async function tick() {
    timer = null;
    if (!canPoll() || inFlight) return;
    inFlight = true;
    try { await poll(); } finally { inFlight = false; }
    if (canPoll()) schedule(delay);
  }

  // ADS-B Exchange altitude is in FEET (and "ground" for on-ground aircraft).
  function altFeet(a) { return typeof a.alt_baro === 'number' ? a.alt_baro : 0; }

  async function poll() {
    let res;
    try {
      res = await fetch(A.proxyMil);
    } catch (err) {
      ui.setStatus('military', 'network error — retrying', 'warn');
      return;
    }
    if (res.status === 503) {
      // Key not configured (e.g. prod before the key is installed) — degrade quietly.
      bc.removeAll();
      ui.setStatus('military', 'ADS-B Exchange not configured', 'warn');
      return;
    }
    if (!res.ok) {
      ui.setStatus('military', `HTTP ${res.status} — retrying`, 'warn');
      return;
    }
    let data;
    try {
      data = await res.json();
    } catch (err) {
      ui.setStatus('military', 'bad response — retrying', 'warn');
      return;
    }

    const list = Array.isArray(data && data.ac) ? data.ac : [];
    bc.removeAll();
    let count = 0;
    let emergencies = 0;
    for (const a of list) {
      if (a.lat == null || a.lon == null) continue;
      const sq = a.squawk;
      const isEmerg = !!EMERG[sq] || (a.emergency && a.emergency !== 'none');
      if (isEmerg) emergencies++;
      bc.add({
        position: Cesium.Cartesian3.fromDegrees(a.lon, a.lat, altFeet(a) * 0.3048),
        image: glyph,
        color: lib.cz(isEmerg ? CONFIG.colors.militaryEmerg : CONFIG.colors.militaryReal),
        rotation: lib.headingToRotation(a.track), // lib negates — track may be absent (→0)
        scale: isEmerg ? 1.05 : 0.82, // bolder than civilian; emergencies bigger still
        id: {
          layer: 'military',
          hex: a.hex,
          callsign: (a.flight || '').trim(),
          type: a.t,
          reg: a.r,
          altFt: altFeet(a),
          gs: a.gs,
          track: a.track,
          squawk: sq,
          emerg: isEmerg ? (EMERG[sq] || String(a.emergency).toUpperCase()) : null,
        },
      });
      count++;
    }

    delay = A.pollMs;
    const stamp = data.now ? new Date(data.now).toLocaleTimeString() : new Date().toLocaleTimeString();
    const em = emergencies ? ` · ${emergencies}⚠` : '';
    ui.setStatus('military', `${count} military · ${stamp}${em}`, emergencies ? 'err' : 'ok');
  }

  function onClockTick(currentTime, live) {
    isLive = live;
    if (!isLive) { bc.show = false; return; } // live-only feed; pause when scrubbed
    bc.show = enabled;
    if (enabled) kick();
  }

  function handlePick(picked) {
    if (picked?.id?.layer !== 'military') return false;
    const id = picked.id;
    const rows = [
      ['Type', id.type || '—'],
      ['Reg', id.reg || '—'],
      ['Altitude', `${Math.round(id.altFt || 0)} ft`],
      ['Speed', `${Math.round(id.gs || 0)} kt`],
      ['Squawk', id.squawk || '—'],
    ];
    if (id.emerg) rows.unshift(['⚠ Status', id.emerg]);
    ui.showPickOverlay('✈ MIL ' + (id.callsign || id.hex || '—'), rows);
    return true;
  }

  function clearPick() { ui.hidePickOverlay(); }

  document.addEventListener('visibilitychange', () => { if (!document.hidden) kick(); });
  kick();

  return { id: 'military', onClockTick, handlePick, clearPick };
}