// PROCITY Lane D — the outdoor gig queue (v3.0-beta charter item, behind ?gigs=1).
//
// While the doors are open, a short line of punters waits at the venue frontage and drains into the
// room as people are admitted — gone by closing (`done`). Street-side companion to the interior
// GigCrew: same gate-protected rig path (spawnRig → buildFigure, so no giants; rigs face -Z after the
// R13 facing-normalise), same placeholder fallback under ?noassets (a queue of boxes is still a queue).
//
// Seam (Lane F wires it from the street-side gig state, per venue):
//   const q = new VenueQueue({ citySeed: plan.citySeed, fleet });
//   q.spawn(streetGroup, { door, queueZone, gigId });   // at 'doors' (and 'on' overflow)
//   q.admitOne();                                        // when a punter is admitted (F's cover-charge / entry hook)
//   q.update(dt);                                        // each street frame — idle shuffle + lerp + slow auto-drain
//   q.disposeAll();                                      // at 'done' / venue out of view
//
// Geometry contract (consistent with the post-R13 -Z rig front):
//   door      = { x, z, ry }            ry = the heading a punter at the door FACES to look at the entrance.
//   queueZone = { x, z, ry, len } | null   Lane B's marker: (x,z) = head by the door, ry = that same facing,
//                                          len = line length (m). Absent → a straight line trailing the door.
// The line trails BEHIND the head (opposite the facing), punters spaced along it, everyone facing the door.

import * as THREE from 'three';
import { rng } from '../core/prng.js';
import { pickRig, spawnRig } from './rigs.js';
import { makePlaceholder } from './placeholder.js';

const SPACING = 0.85;        // m between punters down the line
const QUEUE_MIN = 2, QUEUE_MAX = 6;
const DRAIN_MIN = 3.5, DRAIN_MAX = 7.0;   // s between auto-admissions (seeded) — the safety drain if F
                                          // doesn't couple admitOne() to real entries; empties over the night.
const STEP_EASE = 4.0;       // how fast a punter slides up into a vacated slot

export class VenueQueue {
  constructor({ citySeed = 20261990, fleet = null } = {}) {
    this.citySeed = citySeed >>> 0;
    this.fleet = fleet;
    this.members = [];   // { actor, kind, slot, target:{x,z}, base:{ry}, phase }
    this.parent = null;
    this.gid = 0;
    this._gen = 0;
    this.t = 0;
    this._drainAt = 0;
  }

  // Build the seeded line. `count` overrides the seeded 2..6 (F may cap to the room's spare capacity).
  // onAdmit (R14): fired with {pedIndex,height,key} on EVERY admit (auto-drain or explicit), so F can relay
  // the punter who walked in into the sim's tonight roster (citizens.recordVenueEntry) → they join the crowd.
  spawn(parent, { door = null, queueZone = null, gigId = 0, count = null, onAdmit = null } = {}) {
    this.disposeAll();
    this._gen++;
    this.gid = gigId | 0;
    this.parent = parent;
    this.onAdmit = onAdmit;
    const anchor = this._anchor(door, queueZone);
    if (!anchor) return { queue: 0 };
    this.anchor = anchor;
    const r = rng(this.citySeed, 'queuecount', this.gid);
    const n = count != null ? Math.max(0, count | 0) : QUEUE_MIN + Math.floor(r() * (QUEUE_MAX - QUEUE_MIN + 1));
    for (let i = 0; i < n; i++) this._spawnAt(i);
    this._drainAt = this.t + this._nextDrainGap();
    return { queue: this.members.length };
  }

  // Resolve the head + facing + trail direction from B's zone, else a straight line off the door.
  // Punters always face `ry` (toward the entrance; post-R13 rigs face world (-sin ry, -cos ry)). B's
  // zone trails single-file the opposite way (B lays it down the verandah via x/z/ry/len). The door-only
  // fallback instead trails along the frontage TANGENT, so the line hugs the building rather than spilling
  // into the road — the "along the frontage" read, best-effort until B's queueZone lands.
  _anchor(door, queueZone) {
    const src = queueZone || door;
    if (!src || src.x == null) return null;
    const ry = src.ry || 0;
    const trail = queueZone
      ? { x: Math.sin(ry), z: Math.cos(ry) }         // opposite the facing → classic single file
      : { x: Math.cos(ry), z: -Math.sin(ry) };        // perpendicular to facing → along the frontage
    return { x: src.x, z: src.z, ry, trail, len: queueZone && queueZone.len ? queueZone.len : null };
  }

  _spawnAt(slot) {
    const a = this.anchor;
    // even spacing; if B gave a finite zone length, don't overrun it (compress to fit)
    const gap = (a.len && this.members ? Math.min(SPACING, a.len / Math.max(1, QUEUE_MAX - 1)) : SPACING);
    const tx = a.x + a.trail.x * gap * slot;
    const tz = a.z + a.trail.z * gap * slot;
    const key = `${this.gid}:${slot}`;
    const r = rng(this.citySeed, 'queueh', key);
    const h = 1.58 + r() * 0.34;
    let actor, kind, pedIndex = null;
    if (this.fleet && this.fleet.ready) {
      const pk = pickRig(this.fleet, r());
      pedIndex = pk ? pk.index : null;                          // R14: remember the ped so admitOne can hand it to the crowd
      const rig = pk && this.fleet.all[pk.index];
      const sp = rig && spawnRig(rig, { ry: a.ry, height: h, clip: this.fleet.idleClip, phase: r() });
      if (sp) { actor = sp; kind = 'rig'; }
    }
    if (!actor) { actor = makePlaceholder(rng(this.citySeed, 'queuebody', key), { height: h }); actor.fig.rotation.y = a.ry; kind = 'placeholder'; }
    actor.fig.position.set(tx, 0, tz);
    this.parent.add(actor.fig);
    this.members.push({ actor, kind, slot, pedIndex, height: h, key,   // key = `${gid}:${slot}` — stable per punter (slot shuffles, key doesn't)
      target: { x: tx, z: tz }, base: { ry: a.ry }, phase: rng(this.citySeed, 'queuep', key)() * Math.PI * 2 });
  }

  _gap() {
    const a = this.anchor;
    return (a && a.len ? Math.min(SPACING, a.len / Math.max(1, QUEUE_MAX - 1)) : SPACING);
  }
  _nextDrainGap() { return DRAIN_MIN + rng(this.citySeed, 'queuedrain', `${this.gid}:${this.members.length}:${this.t | 0}`)() * (DRAIN_MAX - DRAIN_MIN); }

  // Admit the head of the line (nearest the door): it walks in, everyone else shuffles up one slot.
  // R14: returns the admitted punter's identity {pedIndex, height, key} (or null when empty) and fires
  // onAdmit(identity) — F relays it to citizens.recordVenueEntry so the punter joins the interior crowd.
  admitOne() {
    if (!this.members.length) return null;
    // the head = the smallest slot (closest to the anchor)
    let headIdx = 0;
    for (let i = 1; i < this.members.length; i++) if (this.members[i].slot < this.members[headIdx].slot) headIdx = i;
    const head = this.members.splice(headIdx, 1)[0];
    if (head.actor.fig.parent) head.actor.fig.parent.remove(head.actor.fig);
    head.actor.dispose && head.actor.dispose();
    const identity = { pedIndex: head.pedIndex, height: head.height, key: head.key };
    // shuffle everyone forward one slot → new target one step closer to the door
    const a = this.anchor, gap = this._gap();
    for (const m of this.members) {
      m.slot = Math.max(0, m.slot - 1);
      m.target.x = a.x + a.trail.x * gap * m.slot;
      m.target.z = a.z + a.trail.z * gap * m.slot;
    }
    this._drainAt = this.t + this._nextDrainGap();
    if (this.onAdmit) this.onAdmit(identity);   // relay the walked-in punter → the crowd roster (auto or explicit)
    return identity;
  }

  // idle shuffle + slide up into vacated slots. The seeded auto-drain is a safety so the line empties
  // over the night even if F doesn't couple admitOne() to real entries; call disposeAll() at `done`.
  update(dt, { autoDrain = true } = {}) {
    this.t += dt;
    const t = this.t;
    if (autoDrain && this.members.length && t >= this._drainAt) this.admitOne();
    for (const m of this.members) {
      if (m.actor.mixer) m.actor.mixer.update(dt);
      else m.actor.tick && m.actor.tick(dt, false);
      const f = m.actor.fig, ph = m.phase;
      // ease toward the (possibly just-vacated) slot
      f.position.x += (m.target.x - f.position.x) * Math.min(1, dt * STEP_EASE);
      f.position.z += (m.target.z - f.position.z) * Math.min(1, dt * STEP_EASE);
      const moving = Math.hypot(m.target.x - f.position.x, m.target.z - f.position.z) > 0.03;
      if (m.actor.setMoving) m.actor.setMoving(moving);
      // waiting-punter fidget: slow weight shift + the odd glance, feet planted
      f.rotation.z = Math.sin(t * 0.8 + ph) * 0.02;
      f.rotation.y = m.base.ry + Math.sin(t * 0.4 + ph) * 0.05;
    }
    return this.members.length;
  }

  count() { return this.members.length; }

  disposeAll() {
    for (const m of this.members) {
      if (m.actor.fig.parent) m.actor.fig.parent.remove(m.actor.fig);
      m.actor.dispose && m.actor.dispose();
    }
    this.members.length = 0;
    this._gen++;
    this.t = 0;
  }
}