/**
 * A joint ties the object it is placed below to another one (#154): a hinge turns round one point, a
 * spring pulls towards a length, a rope allows no more than one, and a fixed joint keeps the two as
 * they were placed, and a slider lets it glide along one axis only. These are the keys of its rows;
 * what the engine reads off them is in `properties/joint.ts`.
 */
export const JOINT_TYPES = ['hinge', 'spring', 'rope', 'fixed', 'slider'] as const;
export type JointType = (typeof JOINT_TYPES)[number];

export const JOINT_TYPE_LABELS: Record<JointType, string> = {
  hinge: 'Hinge',
  spring: 'Spring',
  rope: 'Rope',
  fixed: 'Fixed',
  slider: 'Slider',
};

export const JOINT_TYPE_KEY = 'jointType';
export const JOINT_CONNECTED_KEY = 'connected';
export const JOINT_ANCHOR_X_KEY = 'connectedAnchorX';
export const JOINT_ANCHOR_Y_KEY = 'connectedAnchorY';
export const JOINT_LENGTH_KEY = 'length';
export const JOINT_STIFFNESS_KEY = 'stiffness';
export const JOINT_DAMPING_KEY = 'damping';
export const JOINT_LIMIT_KEY = 'limitAngle';
export const JOINT_MIN_ANGLE_KEY = 'minAngle';
export const JOINT_MAX_ANGLE_KEY = 'maxAngle';
export const JOINT_LIMIT_DISTANCE_KEY = 'limitDistance';
export const JOINT_MIN_DISTANCE_KEY = 'minDistance';
export const JOINT_MAX_DISTANCE_KEY = 'maxDistance';
export const JOINT_MOTOR_KEY = 'motor';
export const JOINT_MOTOR_SPEED_KEY = 'motorSpeed';
export const JOINT_MOTOR_TARGET_KEY = 'motorTarget';
export const JOINT_MAX_FORCE_KEY = 'maxForce';
export const JOINT_COLLIDE_KEY = 'collideConnected';

/** What a motor on a hinge or a slider does: nothing, turn or glide on, or go to a place and stay. */
export const JOINT_MOTORS = ['off', 'speed', 'target'] as const;
export type JointMotor = (typeof JOINT_MOTORS)[number];

export const JOINT_MOTOR_LABELS: Record<JointMotor, string> = {
  off: 'Off',
  speed: 'Speed',
  target: 'Target',
};

/** The types that move along one axis, which a motor can drive and a position can be read of. */
export const AXIS_TYPES: readonly JointType[] = ['hinge', 'slider'];

/** The types with a point of their own on the other end; a hinge and a fixed joint have the one they sit on. */
export const TWO_ANCHOR_TYPES: readonly JointType[] = ['spring', 'rope'];

export function hasConnectedAnchor(type: JointType): boolean {
  return TWO_ANCHOR_TYPES.includes(type);
}