/*!
 * Tectum
 * Copyright © 2026 Machiel Heinen.
 * Alle rechten voorbehouden. Gebruik uitsluitend met schriftelijke toestemming.
 * Zie LICENTIE.md.
 */

function createWalkControls(camera, domElement, opts) {
  const o = Object.assign({ eye: 1.65, speed: 2.1, run: 4.8, turn: Math.PI / 2, blocked: () => false, floorAt: () => 0 }, opts || {});
  const keys = new Set();
  let active = false;
  let x = 0, z = 0, yaw = 0, pitch = 0;
  let drag = null;

  const inField = () => ['INPUT', 'SELECT', 'TEXTAREA'].includes(document.activeElement && document.activeElement.tagName);
  const MOVE_KEYS = ['w', 'a', 's', 'd', 'arrowup', 'arrowdown', 'arrowleft', 'arrowright', 'shift'];
  function onKeyDown(e) {
    if (!active || inField() || e.ctrlKey || e.metaKey || e.altKey) return;
    const k = e.key.toLowerCase();
    if (!MOVE_KEYS.includes(k)) return;
    keys.add(k);
    e.preventDefault();
  }
  function onKeyUp(e) { keys.delete(e.key.toLowerCase()); }
  function onDown(e) { if (active && e.button === 0) drag = { x: e.clientX, y: e.clientY }; }
  function onMove(e) {
    if (!active || !drag) return;
    const w = domElement.clientWidth || 1;
    yaw -= (e.clientX - drag.x) / w * Math.PI;
    pitch = Math.max(-1.2, Math.min(1.2, pitch - (e.clientY - drag.y) / w * Math.PI));
    drag = { x: e.clientX, y: e.clientY };
  }
  function onUp() { drag = null; }
  window.addEventListener('keydown', onKeyDown);
  window.addEventListener('keyup', onKeyUp);
  domElement.addEventListener('pointerdown', onDown);
  window.addEventListener('pointermove', onMove);
  window.addEventListener('pointerup', onUp);

  function apply() {
    camera.position.set(x, o.floorAt(x, z) + o.eye, z);
    // yaw 0 = kijkrichting +Z; pitch > 0 = omhoog.
    const dir = new THREE.Vector3(Math.sin(yaw) * Math.cos(pitch), Math.sin(pitch), Math.cos(yaw) * Math.cos(pitch));
    camera.lookAt(camera.position.clone().add(dir));
  }

  function step(dx, dz) {
    if (!o.blocked(x + dx, z + dz)) { x += dx; z += dz; return; }
    if (!o.blocked(x + dx, z)) x += dx;
    else if (!o.blocked(x, z + dz)) z += dz;
  }

  return {
    get active() { return active; },
    start(pose) {
      x = pose.x; z = pose.z; yaw = pose.yaw || 0; pitch = 0;
      keys.clear();
      active = true;
      apply();
    },
    stop() { active = false; keys.clear(); drag = null; },
    update(dt) {
      if (!active) return;
      const t = Math.min(dt, 0.1);
      if (keys.has('arrowleft')) yaw += o.turn * t;
      if (keys.has('arrowright')) yaw -= o.turn * t;
      const f = (keys.has('w') || keys.has('arrowup') ? 1 : 0) - (keys.has('s') || keys.has('arrowdown') ? 1 : 0);
      const r = (keys.has('d') ? 1 : 0) - (keys.has('a') ? 1 : 0);
      if (f || r) {
        const v = (keys.has('shift') ? o.run : o.speed) * t / Math.hypot(f, r);
        const fx = Math.sin(yaw), fz = Math.cos(yaw);
        const rx = -fz, rz = fx;
        step((fx * f + rx * r) * v, (fz * f + rz * r) * v);
      }
      apply();
    },
    dispose() {
      window.removeEventListener('keydown', onKeyDown);
      window.removeEventListener('keyup', onKeyUp);
      domElement.removeEventListener('pointerdown', onDown);
      window.removeEventListener('pointermove', onMove);
      window.removeEventListener('pointerup', onUp);
    }
  };
}