// PROCITY Lane F — interior_mode.js  [integration glue, F-owned]
// Bridges Lane B's street shell to Lane C's buildInterior library — this is the wiring behind the
// headline "every door opens". Ownership stays clean: Lane B owns the shell + mode machine, Lane C
// owns the room, Lane F owns THIS bridge (a separate module so the shell edits are a thin, marked
// seam rather than logic sprinkled through B's files).
//
// Contract (verified against the real landed code, 2026-07-14):
//   • buildInterior(shop, THREE) → { group(self-lit), spawn:{x,z,ry}, exits:[{x,z,w,toStreet}],
//                                    _debug.grid:{W,D,cols,rows,cw,cd,occ,cellOf}, dispose() }
//   • Room origin = centre, floor y=0. spawn is ~1.5m inside the front door facing −Z into the shop;
//     the (only) street exit sits at the front wall, same x as spawn.
//   • occ cells: 0 free · 1 fitting · 2 wall(border). We collide off occ==1 + room bounds, exactly
//     like Lane C's interior_test.html walk loop, so behaviour matches the tester the room was tuned in.
//
// The interior renders into its OWN dark THREE.Scene (the street scene is frozen, not disposed —
// CITY_SPEC L3 "pause, not dispose"), so returning to the street is instant.

import { buildInterior } from '../interiors/interiors.js';
import { KeeperManager } from '../citizens/keepers.js';   // Lane D — shopkeeper behind the counter

const EYE = 1.6;        // interior eye height (matches interior_test.html; rooms tuned for it)
const RADIUS = 0.30;    // player collision radius inside the room
const SPEED = 3.2;      // interior walk speed (matches the Lane C tester)
const ARM_DIST = 2.0;   // must step this far from the door before the exit arms (spawn is ~1.5m away)
const EXIT_DIST = 1.0;  // …then coming back within this distance leaves to the street

export function createInteriorMode({ THREE, renderer, camera, plan, fleet = null, useGLB = false }) {
  const scene = new THREE.Scene();
  scene.background = new THREE.Color('#0e0b07');

  // Lane D shopkeeper — one per interior, at the counter. With a rig `fleet` (§3.4) the keeper is a
  // shared GLB actor; without one it's an asset-free placeholder. Either way it greets the player.
  const keepers = new KeeperManager({ camera, citySeed: plan.citySeed, fleet });

  let current = null;      // active Lane C interior handle
  let doorReturn = null;   // { x, y, z, ry } on the street to restore on exit
  let exitArmed = false;   // disarmed at spawn (spawn sits by the door); arms once player steps inside

  const _fwd = new THREE.Vector3();
  const _right = new THREE.Vector3();
  const _up = new THREE.Vector3(0, 1, 0);

  // a small unobtrusive banner (F-owned; the street HUD is hidden in interior mode)
  const banner = document.createElement('div');
  banner.style.cssText =
    'position:fixed;left:50%;top:14px;transform:translateX(-50%);z-index:20;display:none;' +
    'background:rgba(20,16,10,.82);color:#f4efe6;padding:8px 16px;border-radius:8px;' +
    'font:14px/1.3 -apple-system,Segoe UI,Roboto,sans-serif;text-shadow:0 1px 2px #000;pointer-events:none';
  document.body.appendChild(banner);

  // interior-grid collision — mirrors interior_test.html walkable(): room bounds + occ==1 fittings.
  function walkable(x, z) {
    const g = current._debug.grid;
    if (Math.abs(x) > g.W / 2 - RADIUS || Math.abs(z) > g.D / 2 - RADIUS) return false;
    for (const [ox, oz] of [[RADIUS, 0], [-RADIUS, 0], [0, RADIUS], [0, -RADIUS]]) {
      const [cx, cz] = g.cellOf(x + ox, z + oz);
      if (g.occ[cz * g.cols + cx] === 1) return false;   // walls are handled by the bounds clamp
    }
    return true;
  }

  function nearestExitDist(px, pz) {
    let best = Infinity;
    for (const e of current.exits) {
      if (e.toStreet === false) continue;
      const d = Math.hypot(px - e.x, pz - e.z);
      if (d < best) best = d;
    }
    return best;
  }

  // enter: build the room, show it, drop the player just inside the door. Returns the Lane C handle.
  function enter(shop, name) {
    if (current) exit();   // never stack interiors
    current = buildInterior(shop, THREE, { useGLB });   // [Lane F §3.4] depot GLB fittings when assets are on
    scene.add(current.group);
    // Lane D keeper at the counter — Lane C tags the stand pose on the counter interactable
    const counter = current.places.find((p) => p.userData && p.userData.keeperStand);
    if (counter) {
      const st = counter.userData.keeperStand;
      keepers.spawn(current.group, { x: st.x, z: st.z, ry: st.ry, shopId: shop.id, type: shop.type });
    }
    doorReturn = { x: camera.position.x, y: camera.position.y, z: camera.position.z, ry: camera.rotation.y };
    camera.position.set(current.spawn.x, EYE, current.spawn.z);
    camera.rotation.set(0, current.spawn.ry, 0, 'YXZ');   // PointerLockControls re-reads this on next mouse move
    exitArmed = false;
    banner.textContent = `🚪 ${name || shop.name || 'shop'} — walk out the door or press Esc to leave`;
    banner.style.display = 'block';
    return current;
  }

  // update: walk + render the interior. Returns true once the player reaches a street exit
  // (the shell then calls exit() + setMode('street') — update never disposes on its own).
  function update(dt, keys) {
    if (!current) return false;
    const f = (keys.has('KeyW') || keys.has('ArrowUp') ? 1 : 0) - (keys.has('KeyS') || keys.has('ArrowDown') ? 1 : 0);
    const s = (keys.has('KeyD') || keys.has('ArrowRight') ? 1 : 0) - (keys.has('KeyA') || keys.has('ArrowLeft') ? 1 : 0);
    if (f || s) {
      camera.getWorldDirection(_fwd); _fwd.y = 0; _fwd.normalize();
      _right.crossVectors(_fwd, _up).normalize();
      const dx = _fwd.x * f + _right.x * s, dz = _fwd.z * f + _right.z * s;
      const len = Math.hypot(dx, dz) || 1;
      const step = SPEED * dt;
      const nx = (dx / len) * step, nz = (dz / len) * step;
      const p = camera.position;
      if (walkable(p.x + nx, p.z)) p.x += nx;   // per-axis → slide along walls/fittings
      if (walkable(p.x, p.z + nz)) p.z += nz;
      p.y = EYE;
    }

    keepers.update(dt);          // Lane D: keeper idle + turn-to-greet (playerPos defaults to the camera)
    renderer.autoClear = true;   // the composer may have left autoClear=false; force a clean interior frame
    renderer.render(scene, camera);

    const de = nearestExitDist(camera.position.x, camera.position.z);
    if (!exitArmed && de > ARM_DIST) exitArmed = true;
    return exitArmed && de < EXIT_DIST;
  }

  // exit: dispose the room (frees GPU + removes group), restore the player to the street door.
  function exit() {
    if (!current) return;
    keepers.disposeAll();   // Lane D: free the keeper actor(s) before the room
    current.dispose();
    current = null;
    banner.style.display = 'none';
    if (doorReturn) {
      camera.position.set(doorReturn.x, doorReturn.y, doorReturn.z);
      camera.rotation.set(0, doorReturn.ry, 0, 'YXZ');
    }
  }

  return {
    enter,
    update,
    exit,
    scene,
    keepers,
    get active() { return !!current; },
    get current() { return current; },
  };
}