const PIXI = 'undefined' !== typeof window ? require('pixi.js') : undefined;

import {Resource} from '@avocado/resource';

export class Image extends Resource {

  constructor() {
    super();
    this.texture = null;
  }

  destroy() {
    this.texture.destroy();
  }

  static fromHtmlCanvas(htmlCanvas) {
    const baseTexture = PIXI.BaseTexture.fromCanvas(
      htmlCanvas,
      PIXI.SCALE_MODES.NEAREST
    );
    const image = new Image();
    image.texture = new PIXI.Texture(baseTexture);
    return image;
  }

  static load(uri) {
    return this.loadBaseTexture(uri).then((baseTexture) => {
      const image = new Image();
      image.uri = uri;
      image.texture = new PIXI.Texture(baseTexture);
      return image;
    });
  }

  static loadBaseTexture(uri) {
    if (!this.baseTextureCache) {
      this.baseTextureCache = {};
    }
    if (this.baseTextureCache[uri]) {
      return Promise.resolve(this.baseTextureCache[uri]);
    }
    return new Promise((resolve, reject) => {
      const baseTexture = PIXI.BaseTexture.fromImage(uri);
      baseTexture.once('error', () => {
        reject(new Error(`Couldn't load image "${uri}"`));
      });
      baseTexture.once('loaded', () => {
        resolve(this.baseTextureCache[uri] = baseTexture);
      });
    });
  }

  get height() {
    if (!this.texture) {
      return 0;
    }
    return this.texture.height;
  }

  get size() {
    return [this.width, this.height];
  }

  subimage(rectangle) {
    const frame = {
      x: rectangle[0],
      y: rectangle[1],
      width: rectangle[2],
      height: rectangle[3],
    };
    const subimage = new Image();
    subimage.texture = new PIXI.Texture(this.texture, frame);
    return subimage;
  }

  updateBaseTexture() {
    if (this.texture && this.texture.baseTexture) {
      this.texture.baseTexture.update();
    }
  }

  get width() {
    if (!this.texture) {
      return 0;
    }
    return this.texture.width;
  }

}