// PROCITY Lane F — gig_state.js  [integration glue, F-owned, round 12 / v3.0-alpha]
// The Friday-night state machine: quiet → doors → on → done, driven off Lane B's day clock and Lane A's
// plan.gigs. F owns it because every other lane consumes it and none of them own the clock:
//   • Lane B  audio.js  reads window.PROCITY.gigs.state → the muffled through-the-wall spill
//   • Lane B  venue.js  update(state)                   → marquee/sign glow on the frontage
//   • Lane D  sim.js    setGig(venueShopId, on)         → the gig-night patronage surge
//   • Lane C  buildInterior(shop, THREE, { gig })       → room.audio.gigKey (the live bed inside)
//   • Lane F  the cover charge at the door + the smokes
//
// Alpha model (CITY_SPEC §"CityPlan v3 — gig layer"): tonight is plan.gigs[0]; startSeg=5 (NIGHT 22:00),
// endSeg=5, doors at startSeg−1 (DUSK). One venue, one genre, seven nightly entries in the plan.
//
// WHY 'done' NEEDS A LATCH. lighting.js's segment→hour map tops out at NIGHT (22:00) and the pub closes at
// 23, so the gig owns the WHOLE night segment — "after the gig" can only be the far side of the wrap, DAWN.
// So: latch while the clock is inside the on-window, hold 'done' for exactly the segment after it (DAWN =
// closing time — the band packs up and the crowd drains per Lane A's closing-time ruling), and clear the
// latch on any other segment → back to 'quiet'. The latch clears on any non-DAWN segment rather than only
// at MORNING because the player drives this clock by hand ([ and ]): rewinding NIGHT → DUSK → ARVO must
// read doors → quiet, not leave 'done' stuck on a midday town (the R12 live verify caught it doing exactly
// that). A night only *counts* as rolled when we leave 'done' FORWARDS — that's what separates a real
// DAWN→MORNING roll (new night, cover due again) from a rewind back out of the gig (same night, paid).
//
// WHY IT LISTENS RATHER THAN POLLS. The latch has to observe every segment, and a poll only sees the
// segments it happens to be sampled on: driving the clock NIGHT→DAWN→MORNING→NIGHT with nothing reading in
// between (player inside the pub, audio muted, so neither the street loop nor the audio rAF is reading)
// skipped the roll entirely — the night never advanced and the cover was never due again. Caught live in
// the R12 verify. lighting.js dispatches `procity:segment` on EVERY segment change (hand-driven or the
// automatic day cycle), so that is the signal the latch rides. Reads stay safe on their own: `state` is a
// getter that re-observes the current segment, and observing the same segment twice is idempotent.

const SEGS = 6;

export function createGigState({ plan, lighting }) {
  const gigs = (plan && plan.gigs) || [];
  const gig = gigs[0] || null;                       // alpha: tonight is gigs[0] (CITY_SPEC v3)
  const startSeg = gig && gig.startSeg != null ? gig.startSeg : 5;
  const endSeg = gig && gig.endSeg != null ? gig.endSeg : 5;
  const doorsSeg = (startSeg - 1 + SEGS) % SEGS;     // DUSK — the doors open
  const doneSeg = (endSeg + 1) % SEGS;               // DAWN — closing time; the only segment 'done' lives in
  // The daytime segments: everything from the morning after the gig up to (not including) the doors —
  // MORNING/MIDDAY/ARVO for the alpha schedule. Landing here after a gig means THE DAY HAS TURNED, which
  // is what rolls the night (and makes the next cover due). See the roll note below.
  const DAYTIME = (() => {
    const set = new Set();
    for (let s = (doneSeg + 1) % SEGS; s !== doorsSeg; s = (s + 1) % SEGS) set.add(s);
    return set;
  })();

  let state = 'quiet';
  let played = false;    // latch: tonight's gig has run (set while inside the on-window)
  let night = 0;         // rolls when the day turns after a gig — keys the cover stamp (runtime only)
  let paidNight = -1;    // the night whose cover is paid; re-entry the same night is free

  // The whole machine, for ONE segment. Idempotent per segment, so it is safe to call from both the
  // event and any read.
  function observe(seg) {
    const on = seg >= startSeg && seg <= endSeg;
    if (on) played = true;
    else if (played && seg !== doneSeg) {
      // The latch is clearing: the gig is behind us. Whether that means "a new night" (cover due again)
      // or "we rewound out of it" (same night, stays paid) is decided by WHERE we land, not by having
      // watched 'done' go by: keying the roll on leaving 'done' meant a clock jump straight from NIGHT to
      // MORNING never rolled the night at all, and a broke punter walked in on last night's stamp. The
      // smoke caught it; stepping ([/]) always passes through DAWN, so only jumps exposed it.
      played = false;
      if (DAYTIME.has(seg)) night++;   // landed in the daytime ⇒ the day turned ⇒ next cover is due
    }                                  // (landed on the doors ⇒ rewound out of the gig ⇒ same night)
    state = on ? 'on' : seg === doorsSeg ? 'doors' : played ? 'done' : 'quiet';
    return state;
  }

  // Every segment change, from [ / ] or the automatic cycle — this is what guarantees no segment is missed.
  const onSegment = (e) => { if (gig && e && e.detail) observe(e.detail.seg); };
  if (typeof window !== 'undefined') window.addEventListener('procity:segment', onSegment);

  function tick() {
    if (!gig || !lighting || !lighting.getClock) return (state = 'quiet');
    return observe(lighting.getClock().seg);
  }
  tick();   // settle on the boot segment

  return {
    get state() { return tick(); },
    update: tick,                                   // shell calls this once per street frame (same thing)
    get on() { return tick() === 'on'; },
    get open() { const s = tick(); return s === 'doors' || s === 'on'; },   // the door is taking punters
    get gig() { return gig; },
    get venueShopId() { return gig ? gig.venueShopId : null; },
    get bandName() { return gig ? gig.bandName : null; },
    get cover() { return gig ? gig.cover | 0 : 0; },
    get night() { return night; },
    // cover stamp — runtime only (like the wallet itself): paid once, free to pop out and back in until the
    // night rolls. NOT persisted, NOT written into the plan (goldens never move).
    get paid() { tick(); return paidNight === night; },
    markPaid() { tick(); paidNight = night; },
    dispose() { if (typeof window !== 'undefined') window.removeEventListener('procity:segment', onSegment); },
  };
}