import {compose} from '@avocado/core';
import {Image, Sprite} from '@avocado/graphics';
import {Vector} from '@avocado/math';

import {simpleState, Trait} from '../trait';

const decorate = compose(
  simpleState('currentFrame', {
    track: true,
  }),
);

class AnimatedBase extends Trait {

  static defaultParams() {
    return {
      frameCount: 0,
      frameRate: 0,
      frameSize: [0, 0],
      image: '',
    };
  }

  static defaultState() {
    return {
      currentFrame: 0,
    };
  }

  constructor(entity, params, state) {
    super(entity, params, state);
    this.sprite = undefined;
    this.frameCount = this.params.get('frameCount');
    this.frameRate = this.params.get('frameRate');
    this.frameSize = this.params.get('frameSize');
    this.image = this.params.get('image');
    this.frameCaret = this.frameRate;
  }

  get frameRect() {
    const direction = ('direction' in this.entity) ? this.entity.direction : 0;
    return [
      this.entity.currentFrame * this.frameSize[0],
      direction * this.frameSize[1],
      this.frameSize[0],
      this.frameSize[1],
    ];
  }

  listeners() {
    return {
      currentFrameChanged: () => {
        if (this.sprite) {
          this.sprite.sourceRectangle = this.frameRect;
        }
      },
      directionChanged: () => {
        if (this.sprite) {
          this.sprite.sourceRectangle = this.frameRect;
        }
      },
      tick: (elapsed) => {
        this.frameCaret -= elapsed;
        if (this.frameCaret > 0) {
          return;
        }
        const newFrame = (this.entity.currentFrame + 1) % this.frameCount;
        this.entity.currentFrame = newFrame;
        if (this.frameCaret < 0) {
          this.frameCaret = this.frameRate - this.frameCaret;
        }
      },
      traitAdded: (trait) => {
        if ('graphical' !== trait.constructor.type()) {
          return;
        }
        if (!this.entity.container.isValid) {
          return;
        }
        Image.load(this.image).then((image) => {
          this.sprite = new Sprite(image);
          this.sprite.sourceRectangle = this.frameRect;
          this.entity.container.addChild(this.sprite);
        });
      },
    };
  }

}

export class Animated extends decorate(AnimatedBase) {}