import React from 'react';
import { Map } from 'immutable';

const reflowable = Component => {
  Object.assign(Component.prototype, {
    _currentBBox() {
      return this.tempBBox ? this.tempBBox : (this.state || {}).bbox;
    },

    setStateAsync(state) {
      return new Promise(resolve => {
        this.setState(state, resolve);
      });
    },

    async setBBox(box, recalculate = {}) {
      const bbox = (this._currentBBox() || Map({ width: 0, height: 0})).withMutations(bbox => {
        bbox.merge(box);

        if (!bbox.has('axisY') || recalculate.axisY) {
          bbox.set('axisY', bbox.get('height') / 2);
        }

        if (!bbox.has('axisX1') || recalculate.axisX1) {
          bbox.set('axisX1', 0);
        }

        if (!bbox.has('axisX2') || recalculate.axisX2) {
          bbox.set('axisX2', bbox.get('width'));
        }
      });

      this.tempBBox = bbox; // Want to get the updated bbox while setState is pending
      await this.setStateAsync({ bbox });
      this.tempBBox = null;
    },

    getBBox() {
      const bbox = this._currentBBox() || Map();
      return {
        width: 0,
        height: 0,
        axisY: 0,
        axisX1: 0,
        axisX2: 0,
        ...bbox.toJS()
      };
    },

    makeRefCollection(collection, count) {
      const diff = Math.abs(collection.length - count);

      if (collection.length < count) {
        const fill = Array.apply(null, new Array(diff)).map(() => React.createRef());
        collection.splice.apply(collection, [collection.length, diff, ...fill]);
      } else if (collection.length > count) {
        collection.splice(collection.length - diff, diff);
      }
    },

    async reflowChildren() {
      // No child components
      if (this.children === undefined) {
        return true;
      }

      const reflowed = await Promise.all(this.children.map(c => c.current.doReflow()));

      return reflowed.reduce((memo, value) => memo || value, false);
    },

    async doReflow() {
      const oldBBox = this._currentBBox();
      const shouldReflow = await this.reflowChildren();

      if (shouldReflow) {
        this.reflow();
      }

      return this._currentBBox() !== oldBBox;
    }
  });

  return Component;
};

export default reflowable;