export type PlanarVector = readonly [x: number, z: number];
export const DEFAULT_CAMERA_PITCH = 0.32;

export function clamp(value: number, minimum: number, maximum: number): number {
  return Math.min(maximum, Math.max(minimum, value));
}

export function applyRadialDeadzone(
  x: number,
  y: number,
  deadzone = 0.18,
): PlanarVector {
  if (!Number.isFinite(x) || !Number.isFinite(y)) return [0, 0];
  const magnitude = Math.hypot(x, y);
  if (magnitude <= deadzone || magnitude === 0) return [0, 0];

  const remappedMagnitude = clamp((magnitude - deadzone) / (1 - deadzone), 0, 1);
  const scale = remappedMagnitude / magnitude;
  return [x * scale, y * scale];
}

export function normalizePlanar(x: number, z: number): PlanarVector {
  if (!Number.isFinite(x) || !Number.isFinite(z)) return [0, 0];
  const magnitude = Math.hypot(x, z);
  if (magnitude <= 1) return [x, z];
  return [x / magnitude, z / magnitude];
}

/** Converts input into world movement for a Three.js +Z-forward player. */
export function cameraRelativeMovement(
  moveX: number,
  moveForward: number,
  yaw: number,
): PlanarVector {
  const [x, forward] = normalizePlanar(moveX, moveForward);
  const safeYaw = Number.isFinite(yaw) ? yaw : 0;
  const sinYaw = Math.sin(safeYaw);
  const cosYaw = Math.cos(safeYaw);
  return [
    -x * cosYaw + forward * sinYaw,
    x * sinYaw + forward * cosYaw,
  ];
}

/** Applies device-right look using the screen-right basis of the +Z camera rig. */
export function cameraYawAfterHorizontalLook(yaw: number, horizontalLook: number): number {
  const safeYaw = Number.isFinite(yaw) ? yaw : 0;
  const safeLook = Number.isFinite(horizontalLook) ? horizontalLook : 0;
  return wrapAngle(safeYaw - safeLook);
}

export function clampCameraPitch(pitch: number): number {
  return Number.isFinite(pitch) ? clamp(pitch, -0.18, 0.88) : DEFAULT_CAMERA_PITCH;
}

export function wrapAngle(angle: number): number {
  return Number.isFinite(angle) ? Math.atan2(Math.sin(angle), Math.cos(angle)) : 0;
}

export function planarDistance(
  from: readonly [number, number, number],
  to: readonly [number, number, number],
): number {
  return Math.hypot(to[0] - from[0], to[2] - from[2]);
}