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

import {Renderable} from './renderable';

export class Container extends Renderable {

  constructor() {
    super();
    this._children = [];
    this._childrenIndexes = new Map();
    this.container = PIXI ? new PIXI.Container() : undefined;
  }

  addChild(child) {
    child.parent = this;
    this.isDirty = true;
    const index = this._children.push(child) - 1;
    this._childrenIndexes.set(child, index);
    this.container.addChild(child.internal);
  }

  get children() {
    return this._children;
  }

  desaturate() {
    let filter = new PIXI.filters.ColorMatrixFilter();
    filter.desaturate();
    this.container.filters = [filter];
  }

  destroy() {
    this.container.filters = [];
    this.children.forEach((child) => {
      this.removeChild(child);
      child.destroy();
    });
    super.destroy();
  }

  get internal() {
    return this.container;
  }

  night(intensity = 1) {
    let filter;
    const {filters} = this.container;
    if (
      filters
      && filters.length > 0
      && filters[0] instanceof PIXI.filters.ColorMatrixFilter
    ) {
      filter = filters[0];
    }
    else {
      filter = new PIXI.filters.ColorMatrixFilter();
    }
    const nightness = 0.1;
    const double = nightness * 2;
    const half = nightness / 2;
    const redDown = 1 - (intensity * (1 + double));
    const blueUp = 1 - (intensity * (1 - half));
    const scale = intensity * nightness;
    const matrix = [
      redDown , -scale         , 0      , 0, 0,
      -scale  , (1 - intensity), scale  , 0, 0,
      0       , scale          , blueUp , 0, 0,
      0       , 0              , 0      , 1, 0,
    ];
    filter._loadMatrix(matrix);
    this.container.filters = [filter];
  }

  paused(intensity = 1) {
    let filter = new PIXI.filters.ColorMatrixFilter();
    filter.sepia();
    filter.brightness(1 - intensity, true);
    this.container.filters = [filter];
  }

  removeAllFilters() {
    this.container.filters = [];
  }

  _removeChild(child) {
    const index = this._children.indexOf(child);
    if (-1 === index) {
      return;
    }
    this._children.splice(index, 1);
    this.container.removeChild(child.internal);
  }

  removeChild(child) {
    this._removeChild(child);
    this._resetChildrenIndexes();
  }

  removeAllChildren() {
    for (const child of this._children) {
      this._removeChild(child);
    }
    this._childrenIndexes = new Map();
  }

  renderTick(elapsed) {
    for (let i = 0; i < this._children.length; i++) {
      const child = this._children[i];
      if (child instanceof Container) {
        child.renderTick(elapsed);
      }
    }
    let needsSort = false;
    let currentZ = -Infinity;
    for (let i = 0; i < this._children.length; i++) {
      const child = this._children[i];
      if (currentZ > child.zIndex) {
        needsSort = true;
        break;
      }
      currentZ = child.zIndex;
    }
    if (!needsSort) {
      return;
    }
    this._children.sort((l, r) => {
      if (l.zIndex !== r.zIndex) {
        return l.zIndex - r.zIndex;
      }
      const lIndex = this._childrenIndexes.get(l);
      const rIndex = this._childrenIndexes.get(r);
      return lIndex - rIndex;
    });
    this.container.children = this._children.map((child) => {
      return child.internal;
    });
    this._resetChildrenIndexes();
  }

  _resetChildrenIndexes() {
    this._childrenIndexes = new Map();
    for (const i in this._children) {
      const child = this._children[i];
      this._childrenIndexes.set(child, i);
    }
  }

  sepia() {
    let filter = new PIXI.filters.ColorMatrixFilter();
    filter.sepia();
    this.container.filters = [filter];
  }

  setFilter(filter) {
    switch (filter) {
      case 'bloom':
        const {AdvancedBloomFilter} = require('@pixi/filter-advanced-bloom');
        this.container.filters = [new AdvancedBloomFilter({
          threshold: 0.5,
          bloomScale: .8,
          brightness: 0.7,
          blur: 2,
          quality: 6,
        })];
        break;
    }
  }

}