import { SystemNames, System } from ".";
import { Game } from "..";
import { ComponentNames } from "../components";
import { Control } from "../components/Control";
import { Action, KeyConstants } from "../config";
import { Entity } from "../entities";
import { Coord2D, Direction } from "../interfaces";

export class Input extends System {
  private keys: Set<string>;
  private mousePosition: Coord2D;

  constructor() {
    super(SystemNames.Input);

    this.keys = new Set();
    this.mousePosition = { x: 0, y: 0 };
  }

  public clearKeys() {
    this.keys.clear();
  }

  public keyPressed(key: string) {
    this.keys.add(key);
  }

  public keyReleased(key: string) {
    this.keys.delete(key);
  }

  public update(_dt: number, game: Game) {
    game.forEachEntityWithComponent(ComponentNames.Control, (entity) =>
      this.handleInput(entity),
    );
  }

  public handleInput(entity: Entity) {
    const controlComponent = entity.getComponent<Control>(
      ComponentNames.Control,
    );
    if (!controlComponent.isControllable) return;

    const hasGrid = entity.hasComponent(ComponentNames.Grid);

    // TODO: check grid via controlComponent to notify entity of interaction
    const [moveUp, moveLeft, moveRight, moveDown] = [
      Action.MOVE_UP,
      Action.MOVE_LEFT,
      Action.MOVE_RIGHT,
      Action.MOVE_DOWN,
    ].map((action) => this.hasSomeKey(KeyConstants.ActionKeys.get(action)));
    if (hasGrid) {
      const gridComponent = entity.getComponent(ComponentNames.Grid);
      if (gridComponent.movingDirection !== Direction.NONE) {
        return;
      }

      if (moveUp) {
        gridComponent.movingDirection = Direction.UP;
        KeyConstants.ActionKeys.get(Action.MOVE_UP)!.forEach((key) =>
          this.keyReleased(key),
        );
      } else if (moveLeft) {
        gridComponent.movingDirection = Direction.LEFT;
        KeyConstants.ActionKeys.get(Action.MOVE_LEFT)!.forEach((key) =>
          this.keyReleased(key),
        );
      } else if (moveRight) {
        gridComponent.movingDirection = Direction.RIGHT;
        KeyConstants.ActionKeys.get(Action.MOVE_RIGHT)!.forEach((key) =>
          this.keyReleased(key),
        );
      } else if (moveDown) {
        gridComponent.movingDirection = Direction.DOWN;
        KeyConstants.ActionKeys.get(Action.MOVE_DOWN)!.forEach((key) =>
          this.keyReleased(key),
        );
      }

      entity.addComponent(gridComponent);
    }
  }

  private hasSomeKey(keys?: string[]): boolean {
    if (keys) {
      return keys.some((key) => this.keys.has(key));
    }
    return false;
  }

  public setMousePosition(mousePosition: Coord2D) {
    this.mousePosition = mousePosition;
  }

  public getMousePosition(): Coord2D {
    return this.mousePosition;
  }
}