// PROCITY Lane F — gig_state.js  [integration glue, F-owned, round 13 / v3.0-beta THE DISTRICT]
// The Friday-night state machine, now PER-VENUE. A town has 2–4 venues (pub / band_room / rsl); each runs
// its own latch quiet → doors → on → done 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.byVenue[id] → the muffled through-the-wall spill per venue
//   • Lane B  venue.js  update(byVenue)                       → marquee/sign glow on each frontage
//   • Lane D  sim.js    setGig(venueShopId, on)               → the gig-night patronage surge, per venue
//   • Lane C  buildInterior(shop, THREE, { gig })             → room.audio.gigKey (the live bed inside)
//   • Lane F  the cover charge at each door + the smokes
//
// Model (CITY_SPEC §"CityPlan v3 — gig layer"): plan.gigs is the whole week × every venue. TONIGHT for a
// venue is its night-0 entry (the same night-0 convention A's posters and B's frontage key off); a venue
// dark tonight has no latch gig → reads 'quiet' all session, which is true to the seeded schedule. Each
// venue's night rolls the same way (clock turns → next cover due), so a night at two venues is two covers.
//
// ── THREE HARD-WON LAWS, unchanged from the alpha (they each cost a live-verify to learn): ──────────────
// WHY 'done' NEEDS A LATCH. lighting.js's segment→hour map tops out at NIGHT (22:00) and a venue closes at
// closing time, 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, the crowd drains per Lane A's closing ruling), and clear on
// any other segment → back to 'quiet'. The latch clears on any non-DAWN segment (not only at MORNING)
// because the player drives the 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).
//
// WHY THE NIGHT ROLLS ON WHERE THE CLOCK LANDS, not on watching 'done' go by. First cut incremented the
// night when LEAVING 'done' forwards — so a clock JUMP straight from NIGHT to MORNING (never touching DAWN)
// never rolled the night, and a broke punter walked in on last night's paid stamp. Now: the latch clears
// wherever it clears, and landing in the DAYTIME (MORNING…ARVO) is what rolls the night; landing on the
// doors means we rewound out of the gig — same night, stays paid. DBG/shots/soak all JUMP, so only this
// rule survives them.
//
// WHY IT LISTENS RATHER THAN POLLS. Each latch must observe EVERY segment; a poll only sees the segments it
// is sampled on. Driving the clock NIGHT→DAWN→MORNING→NIGHT with nothing reading in between (player inside a
// venue, 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. lighting.js dispatches `procity:segment` on
// EVERY segment change (hand-driven or the auto day cycle), so that is the signal every 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;

// One venue's latch — the alpha machine, its hard-won internals verbatim. `gig` is this venue's tonight
// (night-0) entry, or null when the venue is dark tonight (→ always 'quiet').
function createVenueLatch(gig, lighting) {
  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.
  // Landing here after a gig means THE DAY HAS TURNED, which rolls the night (next cover due).
  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
  // procity:segment 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's "a new night" (cover due again) or
      // "we rewound out of it" (same night, stays paid) is decided by WHERE we land, not by watching
      // 'done' go by (see the roll law in the header).
      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;
  }

  function tick() {
    if (!gig || !lighting || !lighting.getClock) return (state = 'quiet');
    return observe(lighting.getClock().seg);
  }

  return {
    gig, observe, tick,
    get state() { return tick(); },
    get on() { return tick() === 'on'; },
    get open() { const s = tick(); return s === 'doors' || s === 'on'; },   // the door is taking punters
    get cover() { return gig ? gig.cover | 0 : 0; },
    get bandName() { return gig ? gig.bandName : null; },
    get night() { tick(); return night; },
    // cover stamp — runtime only (like the wallet): 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; },
  };
}

export function createGigState({ plan, lighting }) {
  const gigs = (plan && plan.gigs) || [];
  // The district's venues, in first-seen (gigId) order. Primary = gigs[0].venueShopId — the alpha's
  // "tonight", kept as the compat alias so B's mid-round single-venue callers still light the right pub.
  const venueIds = [...new Set(gigs.map((g) => g.venueShopId))];
  const primaryId = gigs.length ? gigs[0].venueShopId : null;

  // one latch per venue, keyed by its night-0 gig (null → dark tonight → 'quiet')
  const latch = new Map();
  for (const id of venueIds) {
    const tonight = gigs.find((g) => g.venueShopId === id && g.night === 0) || null;
    latch.set(id, createVenueLatch(tonight, lighting));
  }

  // ONE listener drives every latch — the listens-not-polls law, now fanned out across the district.
  const onSegment = (e) => { if (e && e.detail) for (const l of latch.values()) l.observe(e.detail.seg); };
  if (typeof window !== 'undefined') window.addEventListener('procity:segment', onSegment);

  function tickAll() { for (const l of latch.values()) l.tick(); }
  tickAll();   // settle every latch on the boot segment

  const L = (id) => latch.get(id) || null;
  const P = () => L(primaryId);

  return {
    // ── per-venue API (R13 district) ──────────────────────────────────────────────────────────────
    get venueShopIds() { return venueIds.slice(); },
    stateOf(id) { const l = L(id); return l ? l.state : 'quiet'; },
    onOf(id) { const l = L(id); return l ? l.on : false; },
    openOf(id) { const l = L(id); return l ? l.open : false; },
    gigOf(id) { const l = L(id); return l ? l.gig : null; },
    coverOf(id) { const l = L(id); return l ? l.cover : 0; },
    bandNameOf(id) { const l = L(id); return l ? l.bandName : null; },
    nightOf(id) { const l = L(id); return l ? l.night : 0; },
    paidOf(id) { const l = L(id); return l ? l.paid : false; },
    markPaidOf(id) { const l = L(id); if (l) l.markPaid(); },
    // the map B's venue.update() and audio.js consume: a fresh { [venueShopId]: 'quiet'|'doors'|'on'|'done' }.
    // Called per street frame over a handful of venues — cheap.
    get byVenue() { const o = {}; for (const [id, l] of latch) o[id] = l.tick(); return o; },
    // shell calls this once per street frame — ticks every latch (so B/D read fresh state) and returns the
    // primary state for the alpha-compat caller.
    update() { tickAll(); return P() ? P().state : 'quiet'; },

    // ── alpha-shape alias → the PRIMARY venue (kept for one round; B reads it mid-round) ─────────────
    get state() { const p = P(); return p ? p.state : 'quiet'; },
    get on() { const p = P(); return p ? p.on : false; },
    get open() { const p = P(); return p ? p.open : false; },
    get gig() { const p = P(); return p ? p.gig : null; },
    get venueShopId() { return primaryId; },
    get bandName() { const p = P(); return p ? p.bandName : null; },
    get cover() { const p = P(); return p ? p.cover : 0; },
    get night() { const p = P(); return p ? p.night : 0; },
    get paid() { const p = P(); return p ? p.paid : false; },
    markPaid() { const p = P(); if (p) p.markPaid(); },

    dispose() { if (typeof window !== 'undefined') window.removeEventListener('procity:segment', onSegment); },
  };
}