import {compose} from '@avocado/core';
import {Rectangle, Vector} from '@avocado/math';

const decorate = compose(
  Vector.Mixin('size', 'width', 'height', {
    default: [0, 0],
  }),
);

class TilesBase {

  fromJSON(json) {
    if (json.size) {
      this.size = json.size;
    }
    if (json.data) {
      this.data = json.data;
    }
    return this;
  }

  get rectangle() {
    return Rectangle.compose([0, 0], this.size);
  }

  slice(rectangle) {
    const tilesRectangle = this.rectangle;
    if (!Rectangle.intersects(rectangle, tilesRectangle)) {
      return [];
    }
    let [x, y, width, height] = Rectangle.intersection(rectangle, tilesRectangle);
    const rowWidth = tilesRectangle[2];
    const slice = new Array(width * height);
    for (let j = 0; j < height; ++j) {
      for (let i = 0; i < width; ++i) {
        slice[y * width + x] = this.data[y * rowWidth + x];
        x++;
      }
      y++;
      x -= width;
    }
    return slice;
  }

  tileAt(x, y) {
    const [width, height] = this.size;
    return this.data[y * width + x];
  }

  toJSON() {

  }

}

export class Tiles extends decorate(TilesBase) {}