// PROCITY Lane B — hud.js
// The street HUD: crosshair, shop-name tooltip (throttled centre-screen raycast, far = 6m),
// time-of-day + seed + live perf readout (renderer.info: draw calls & triangles), and the
// door-click → `procity:enterShop` hand-off. Creates its own DOM overlay so index.html stays thin.

import * as THREE from 'three';
import { osmTownKeys } from '../citygen/index.js';   // R19 town selector: enumerate OSM fixtures

// R21 (v4.0-beta, ledger #2): the real-roads towns come from E's index (web/assets/towns/index.json), so the
// list grows with the town pack instead of being edited here. This literal is now only the FAIL-SOFT fallback
// — used when the index is missing/unparseable, or under ?noassets (where the shell doesn't fetch town caches
// either, so reading the index would be both pointless and against the asset law). Zero errors either way.
const REAL_TOWNS_FALLBACK = ['katoomba_real', 'newtown_real', 'fremantle_real', 'bendigo_real', 'castlemaine_real'];
const TOWNS_INDEX = 'assets/towns/index.json';

const CSS = `
#pc-hud{position:fixed;inset:0;pointer-events:none;font:13px/1.4 -apple-system,Segoe UI,Roboto,sans-serif;color:#f4efe6;z-index:10}
#pc-cross{position:absolute;left:50%;top:50%;width:6px;height:6px;margin:-3px 0 0 -3px;border-radius:50%;background:#fff;opacity:.7;box-shadow:0 0 3px #000}
#pc-tip{position:absolute;left:50%;top:calc(50% + 22px);transform:translateX(-50%);background:rgba(20,16,10,.82);padding:6px 12px;border-radius:6px;white-space:nowrap;opacity:0;transition:opacity .12s;text-shadow:0 1px 2px #000}
#pc-dbg{position:absolute;right:10px;top:10px;text-align:right;background:rgba(20,16,10,.55);padding:8px 11px;border-radius:8px;min-width:150px}
#pc-dbg b{color:#ffd75e;font-weight:600}
#pc-dbg .warn{color:#ff9a6a}
#pc-clock{font-size:15px;margin-bottom:3px}
#pc-toast{position:absolute;left:50%;bottom:64px;transform:translateX(-50%);background:rgba(20,16,10,.9);padding:10px 18px;border-radius:10px;font-size:15px;opacity:0;transition:opacity .25s;text-shadow:0 1px 2px #000}
#pc-help{position:absolute;left:12px;bottom:12px;background:rgba(20,16,10,.5);padding:7px 11px;border-radius:8px;opacity:.85}
#pc-townpick{position:absolute;left:10px;top:10px;pointer-events:auto;opacity:.8;transition:opacity .12s}
#pc-townpick:hover{opacity:1}
#pc-townpick select{background:rgba(20,16,10,.7);color:#f4efe6;border:1px solid rgba(255,215,94,.35);border-radius:8px;padding:5px 9px;font:12px/1.3 -apple-system,Segoe UI,Roboto,sans-serif;max-width:230px;cursor:pointer}
#pc-townpick select:focus{outline:1px solid rgba(255,215,94,.6)}
`;

export function createHUD({ camera, renderer, plan, getDoorMeshes, onEnterShop }) {
  if (!document.getElementById('pc-hud-style')) {
    const st = document.createElement('style'); st.id = 'pc-hud-style'; st.textContent = CSS;
    document.head.appendChild(st);
  }
  const root = document.createElement('div'); root.id = 'pc-hud';
  root.innerHTML = `
    <div id="pc-cross"></div>
    <div id="pc-tip"></div>
    <div id="pc-dbg">
      <div id="pc-clock">—</div>
      <div>town <b id="pc-town">—</b></div>
      <div>seed <b id="pc-seed">—</b></div>
      <div>fps <b id="pc-fps">—</b></div>
      <div>draws <b id="pc-draws">—</b> · tris <b id="pc-tris">—</b></div>
      <div>chunks <b id="pc-chunks">—</b></div>
    </div>
    <div id="pc-toast"></div>
    <div id="pc-townpick"><select id="pc-town-select" title="Load a different town (Esc to release the pointer first)"></select></div>
    <div id="pc-help">WASD move · shift run · mouse look · click a door · [ ] time · P shot · Esc release</div>`;
  document.body.appendChild(root);
  const $ = (id) => root.querySelector('#' + id);
  const elTip = $('pc-tip'), elClock = $('pc-clock'), elFps = $('pc-fps'), elDraws = $('pc-draws'),
    elTris = $('pc-tris'), elChunks = $('pc-chunks'), elToast = $('pc-toast');
  $('pc-town').textContent = plan.name || '—';
  $('pc-seed').textContent = plan.citySeed;

  // ── town selector (R19; R21 reads E's towns index) — synthetic + OSM fixtures + real-road towns.
  // Navigates to the matching URL params, preserving everything else (seed, flags). Lives in the HUD
  // overlay, so it hides with the HUD for money shots; usable when the pointer is free (Esc). No
  // index.html seam. The real-town list is built SYNCHRONOUSLY from the fallback (so the picker always
  // works, including under ?noassets and if the index 404s), then upgraded in place once E's index.json
  // resolves — which also gives real names, states and shop counts. ──
  (() => {
    const sel = $('pc-town-select'); if (!sel) return;
    const params = new URLSearchParams(location.search);
    const cur = params.get('plansrc') === 'osm' ? (params.get('town') || '') : '';
    const NOASSETS = params.get('noassets') != null && params.get('noassets') !== '0';
    const cap = (k) => k.replace(/_real$/, '').replace(/(^|[\s_])\w/g, (c) => c.toUpperCase()).replace(/_/g, ' ');
    const opt = (key, label) => { const o = document.createElement('option'); o.value = key; o.textContent = label; if (key === cur) o.selected = true; return o; };
    const build = (realTowns) => {
      sel.textContent = '';
      sel.appendChild(opt('', '▸ Synthetic — procedural'));
      for (const k of osmTownKeys().filter((k) => !k.endsWith('_real'))) sel.appendChild(opt(k, `${cap(k)} · OSM fixture`));
      for (const t of realTowns) sel.appendChild(opt(t.key, t.label));
      if (cur && !Array.from(sel.options).some((o) => o.value === cur)) sel.appendChild(opt(cur, `${cap(cur)} · (current)`));   // unknown current town → still shown
    };
    build(REAL_TOWNS_FALLBACK.map((k) => ({ key: k, label: `${cap(k)} · real roads` })));
    sel.onchange = () => {   // set once; rebuilding the options below never clears it
      const v = sel.value, p = new URLSearchParams(location.search);
      if (!v) { p.delete('plansrc'); p.delete('town'); } else { p.set('plansrc', 'osm'); p.set('town', v); }
      location.search = p.toString();   // reload into the chosen town
    };
    if (NOASSETS) return;               // asset law: no fetch — the fallback list stands
    fetch(TOWNS_INDEX, { cache: 'force-cache' })
      .then((r) => (r.ok ? r.json() : null))
      .then((j) => {
        const towns = j && Array.isArray(j.towns) ? j.towns.filter((t) => t && t.key) : null;
        if (!towns || !towns.length) return;   // keep the fallback, silently
        build(towns.map((t) => ({
          key: t.key,
          label: `${t.town || cap(t.key)}${t.state ? ', ' + t.state : ''}`
            + (t.shops != null ? ` · ${t.shops} shops` : '')
            + (t.roads === false ? ' · marched' : ''),
        })));
      })
      .catch(() => {});                 // index missing/blocked → fallback stands, zero errors
  })();

  const ray = new THREE.Raycaster();
  ray.far = 6;
  const centre = new THREE.Vector2(0, 0);
  let hovered = null;   // { shopId, name }
  let frame = 0, fpsAcc = 0, fpsCount = 0, fpsShown = 0;

  function nearestDoor(rects, point) {
    let best = null, bd = Infinity;
    for (const r of rects) {
      const d = (r.x - point.x) ** 2 + (r.z - point.z) ** 2;
      if (d < bd) { bd = d; best = r; }
    }
    return best;
  }

  function raycastDoor() {
    const meshes = getDoorMeshes ? getDoorMeshes() : [];
    if (!meshes.length) { hovered = null; return; }
    ray.setFromCamera(centre, camera);
    const hits = ray.intersectObjects(meshes, false);
    if (hits.length) {
      const h = hits[0];
      const rects = h.object.userData.doorRects || [];
      const door = nearestDoor(rects, h.point);
      hovered = door ? { shopId: door.shopId, name: door.name, hours: door.hours } : null;
    } else {
      hovered = null;
    }
  }

  function update(dt, info) {
    // fps (smoothed over ~0.4s)
    fpsAcc += dt; fpsCount++;
    if (fpsAcc >= 0.4) { fpsShown = Math.round(fpsCount / fpsAcc); fpsAcc = 0; fpsCount = 0; }

    frame++;
    if (frame % 6 === 0) raycastDoor();

    // tooltip — shows CLOSED (with opening hour) when the shop is shut at the current hour (§3.5)
    if (hovered) {
      const h = hovered.hours;
      const now = window.PROCITY && window.PROCITY.currentHour ? window.PROCITY.currentHour() : null;
      const closed = h && now != null && !(now >= h[0] && now < h[1]);
      elTip.textContent = closed
        ? `🔒 ${hovered.name} — CLOSED · opens ${String(h[0]).padStart(2, '0')}:00`
        : `🚪 ${hovered.name} — click to enter`;
      elTip.style.opacity = 1;
    } else elTip.style.opacity = 0;

    // debug readout
    if (info) {
      if (info.clock) elClock.textContent = `${info.clock.label} ${info.clock.hour}${info.clock.night ? ' 🌙' : ''}`;
      elFps.textContent = fpsShown;
      const draws = renderer.info.render.calls, tris = renderer.info.render.triangles;
      elDraws.innerHTML = draws > 300 ? `<span class="warn">${draws}</span>` : draws;
      elTris.innerHTML = tris > 200000 ? `<span class="warn">${(tris / 1000 | 0)}k</span>` : `${(tris / 1000 | 0)}k`;
      if (info.chunks != null) elChunks.textContent = info.chunks;
    }
  }

  let toastT = 0;
  function showToast(msg, secs = 2.6) {
    elToast.textContent = msg; elToast.style.opacity = 1; toastT = secs;
  }
  function tickToast(dt) { if (toastT > 0) { toastT -= dt; if (toastT <= 0) elToast.style.opacity = 0; } }

  // door click → enter shop (only when hovering one)
  function onClick() {
    if (hovered && onEnterShop) onEnterShop(hovered.shopId, hovered.name);
  }
  renderer.domElement.addEventListener('click', onClick);

  function setVisible(v) { root.style.display = v ? 'block' : 'none'; }

  function dispose() {
    renderer.domElement.removeEventListener('click', onClick);
    root.remove();
  }

  return { update, tickToast, showToast, setVisible, dispose, getHovered: () => hovered,
    getFps: () => fpsShown };
}