import Resource from './resource'

let imageCache = {}

class Image {
  constructor (file, img) {
    this.file = file
    this.img = img
  }

  static async load (file) {
    if (imageCache[file]) return imageCache[file]
    let img = await Resource.loadImage(file)
    let imgCl = new Image(file, img)
    imageCache[file] = imgCl
    return imgCl
  }

  get width () {
    return this.img.width
  }

  get height () {
    return this.img.height
  }

  draw (ctx, x, y, w, h) {
    ctx.drawImage(this.img, x, y, w, h)
  }
}

class TileMap extends Image {
  constructor (file, img, xaspect, yaspect) {
    super(file, img)
    this.xaspect = xaspect
    this.yaspect = yaspect
    this.xcount = this.width / xaspect
    this.ycount = this.height / yaspect
    this.tiles = []

    for (let y = 0; y < this.ycount; y++) {
      for (let x = 0; x < this.xcount; x++) {
        this.tiles.push({ x, y })
      }
    }
  }

  draw (ctx, index, x, y, w, h) {
    let box = this.tiles[index]
    if (!box) return
    ctx.drawImage(this.img, box.x * this.xaspect, box.y * this.yaspect, this.xaspect, this.yaspect, x, y, w, h)
  }

  static async load (file, x, y) {
    if (imageCache[file]) return imageCache[file]
    let img = await Resource.loadImage(file, true)
    let imgCl = new TileMap(file, img, x, y)
    imageCache[file] = imgCl
    return imgCl
  }
}

export { Image, TileMap }