type state = 'down' | 'up';

// - TODO - Pull this from the actual game creating the controls
const GameControls = {
  down: 'down',
  up: 'up',
  left: 'left',
  right: 'right',
  shift: 'shift',
  ' ': ' ',
} as const;

/**
 * Abstraction for game controls, the game should say what controls it expects and then we can remap the actual controls separately.  
 * i.e. Both "ArrowDown" and "Down" from the keyboard listener should be the games "down" event.  
 * Also handles when the keys are pressed or not.
 */
class Control {
  readonly gameControls = GameControls;
  private _controlMap: { [key: string]: keyof typeof GameControls } = {
    ArrowDown: GameControls.down,
    Down: GameControls.down,
    ArrowUp: GameControls.up,
    Up: GameControls.up,
    ArrowLeft: GameControls.left,
    Left: GameControls.left,
    ArrowRight: GameControls.right,
    Right: GameControls.right,
    Shift: GameControls.shift,
    ' ': GameControls[' '],
  };

  private _controlState: Map<keyof typeof GameControls, {
    state: state,

    consumed: boolean
  }> = new Map();

  constructor() {
    this._setKeys();
    window.addEventListener('keydown', (event) => {
      if (this._controlState.get(this._controlMap[event.key])?.state !== 'down') {
        this._controlState.set(this._controlMap[event.key], { state: 'down', consumed: false });
      }
    });

    window.addEventListener('keyup', (event) => {
      if (this._controlState.get(this._controlMap[event.key])?.state !== 'up') {
        this._controlState.set(this._controlMap[event.key], { state: 'up', consumed: false });
      }
    });
  }

  /**
   * - TODO
   */
  private _setKeys(): void {
    Object.keys(GameControls).forEach((key) => {
      this._controlState.set(key as keyof typeof GameControls, { state: 'up', consumed: false });
    });
  }

  /**
   * - TODO
   *
   * @param key - TODO
   */
  isDown(key: keyof typeof GameControls): boolean {
    return this._controlState.get(key)?.state === 'down';
  }

  /**
   * Consume a down key event once
   * 
   * @param key  - TODO
   */
  onceDown(key: keyof typeof GameControls): boolean {
    const keyState = this._controlState.get(key);
    if (keyState && keyState.state === 'down' && !keyState.consumed) {
      keyState.consumed = true;
      return true;
    }
    return false;
  }
}

export default Control;