import { MathUtils, PerspectiveCamera, type Vector3 } from 'three';
import { SCENE } from '../constants/scene.ts';
import { MOVEMENT } from '../constants/movement.ts';

export function createFpsCameraController(camera: PerspectiveCamera, canvas: HTMLCanvasElement,
  pickDestination: (x: number, y: number) => Vector3 | null,
  options: { onTurn?: (radians: number) => void; onZoom?: (factor: number) => void;
    onSelect?: (x: number, y: number) => boolean; onModeChange?: (turning: boolean) => void } = {}) {
  let destination: Vector3 | null = null;
  let arrivalYaw: number | undefined;
  let turning = false;
  const pointers = new Map<number, { x: number; y: number }>();
  let pinched = false;
  const pinchDistance = () => {
    const [a, b] = [...pointers.values()];
    return a && b ? Math.hypot(a.x - b.x, a.y - b.y) : 0;
  };
  let gesture: { id: number; startX: number; startY: number; x: number; y: number; dragged: boolean; canMove: boolean } | null = null;
  canvas.tabIndex = 0;
  const cancelGesture = () => {
    const ids = [...pointers.keys()];
    gesture = null;
    pointers.clear(); pinched = false;
    for (const id of ids) if (canvas.hasPointerCapture(id)) canvas.releasePointerCapture(id);
  };
  const stop = () => { destination = null; arrivalYaw = undefined; };
  const blur = () => { stop(); cancelGesture(); };
  const setTurning = (value: boolean) => {
    stop(); cancelGesture(); turning = value; options.onModeChange?.(value);
  };
  const clear = () => setTurning(false);
  const down = (event: PointerEvent) => {
    if (pointers.size >= 2 || (event.pointerType !== 'touch' && (!event.isPrimary || pointers.size))
      || (event.button !== 0 && event.button !== 2)) return;
    event.preventDefault();
    canvas.focus({ preventScroll: true });
    pointers.set(event.pointerId, { x: event.clientX, y: event.clientY });
    canvas.setPointerCapture(event.pointerId);
    if (pointers.size > 1) { pinched = true; return; }
    gesture = { id: event.pointerId, startX: event.clientX, startY: event.clientY,
      x: event.clientX, y: event.clientY, dragged: false, canMove: event.pointerType !== 'mouse' || event.button === 2 };
  };
  const move = (event: PointerEvent) => {
    if (!pointers.has(event.pointerId)) return;
    const before = pinchDistance();
    pointers.set(event.pointerId, { x: event.clientX, y: event.clientY });
    if (pinched) {
      const after = pinchDistance();
      if (before > 0 && after > 0) options.onZoom?.(before / after);
      return;
    }
    if (!gesture || gesture.id !== event.pointerId) return;
    if (Math.hypot(event.clientX - gesture.startX, event.clientY - gesture.startY) > MOVEMENT.dragThreshold) gesture.dragged = true;
    if (gesture.dragged) {
      if (turning) options.onTurn?.((event.clientX - gesture.x) * MOVEMENT.turnSensitivity);
      else {
        camera.rotation.reorder('YXZ');
        camera.rotation.y -= (event.clientX - gesture.x) * MOVEMENT.dragSensitivity;
        camera.rotation.x = MathUtils.clamp(camera.rotation.x - (event.clientY - gesture.y) * MOVEMENT.dragSensitivity,
          -MathUtils.degToRad(SCENE.pitchLimitDegrees), MathUtils.degToRad(SCENE.pitchLimitDegrees));
      }
    }
    gesture.x = event.clientX;
    gesture.y = event.clientY;
  };
  const up = (event: PointerEvent) => {
    if (!pointers.has(event.pointerId)) return;
    if (pinched) {
      pointers.delete(event.pointerId);
      if (canvas.hasPointerCapture(event.pointerId)) canvas.releasePointerCapture(event.pointerId);
      if (!pointers.size) cancelGesture();
      return;
    }
    if (!gesture || gesture.id !== event.pointerId) return;
    const tap = !gesture.dragged && Math.hypot(event.clientX - gesture.startX, event.clientY - gesture.startY) <= MOVEMENT.dragThreshold;
    if (tap && !turning) {
      if (options.onSelect?.(event.clientX, event.clientY)) stop();
      else if (gesture.canMove) { destination = pickDestination(event.clientX, event.clientY); arrivalYaw = undefined; }
    }
    cancelGesture();
  };
  const cancel = (event: PointerEvent) => { if (pointers.has(event.pointerId)) cancelGesture(); };
  const wheel = (event: WheelEvent) => {
    if (!options.onZoom) return;
    event.preventDefault();
    options.onZoom(Math.exp(MathUtils.clamp(event.deltaY, -100, 100) * MOVEMENT.wheelSensitivity));
  };
  const escape = (event: KeyboardEvent) => { if (event.code === 'Escape') clear(); };
  const contextMenu = (event: Event) => event.preventDefault();
  window.addEventListener('blur', clear);
  window.addEventListener('keydown', escape);
  canvas.addEventListener('blur', blur);
  canvas.addEventListener('wheel', wheel, { passive: false });
  document.addEventListener('visibilitychange', clear);
  canvas.addEventListener('pointerdown', down);
  canvas.addEventListener('pointermove', move);
  canvas.addEventListener('pointerup', up);
  canvas.addEventListener('pointercancel', cancel);
  canvas.addEventListener('lostpointercapture', cancel);
  canvas.addEventListener('contextmenu', contextMenu);
  return {
    get destination() { return destination; },
    get arrivalYaw() { return arrivalYaw; },
    get turning() { return turning; },
    setTurning,
    moveTo(point: Vector3, yaw?: number) { setTurning(false); destination = point.clone(); arrivalYaw = yaw; },
    stop,
    active() { return document.activeElement === canvas; },
    clear,
    dispose() {
      clear();
      window.removeEventListener('blur', clear);
      window.removeEventListener('keydown', escape);
      canvas.removeEventListener('blur', blur);
      canvas.removeEventListener('wheel', wheel);
      document.removeEventListener('visibilitychange', clear);
      canvas.removeEventListener('pointerdown', down);
      canvas.removeEventListener('pointermove', move);
      canvas.removeEventListener('pointerup', up);
      canvas.removeEventListener('pointercancel', cancel);
      canvas.removeEventListener('lostpointercapture', cancel);
      canvas.removeEventListener('contextmenu', contextMenu);
    },
  };
}