import Game from "@/core/Game";

type HorizontalAlign = "left" | "center" | "right" | number;
type VerticalAlign = "top" | "center" | "bottom" | number;

interface PositionOptions {
  x?: number;
  y?: number;
}

class Position {
  private game: Game;

  constructor() {
    this.game = Game.getInstance();
  }

  get(
    hAlign: HorizontalAlign,
    vAlign: VerticalAlign,
    options?: PositionOptions
  ): { x: number; y: number } {
    const { width, height } = this.game.getInfo();

    let x: number;
    let y: number;

    // 水平对齐
    if (hAlign === "left") {
      x = 0;
    } else if (hAlign === "center") {
      x = width / 2;
    } else if (hAlign === "right") {
      x = width;
    } else {
      x = hAlign;
    }

    // 垂直对齐
    if (vAlign === "top") {
      y = 0;
    } else if (vAlign === "center") {
      y = height / 2;
    } else if (vAlign === "bottom") {
      y = height;
    } else {
      y = vAlign;
    }

    // 添加偏移
    if (options) {
      x += options.x ?? 0;
      y += options.y ?? 0;
    }

    return { x, y };
  }

  center(options?: PositionOptions): { x: number; y: number } {
    return this.get("center", "center", options);
  }

  centerX(y: VerticalAlign, options?: PositionOptions): { x: number; y: number } {
    return this.get("center", y, options);
  }

  centerY(x: HorizontalAlign, options?: PositionOptions): { x: number; y: number } {
    return this.get(x, "center", options);
  }
}

export const position = new Position();
export default position;