import * as I from 'immutable';

import {compose} from '@avocado/core';
import {Property} from '@avocado/mixins';

import {StateSynchronizer} from './synchronizer';

const decorate = compose(
  Property('state'),
);

export class Synchronized extends decorate(class {}) {

  constructor() {
    super();
    this.state = I.Map();
  }

  synchronizedChildren() {
    return [];
  }

  patchState(patch) {
    for (const step of patch) {
      const {op, path, value} = step;
      if ('/' === path) {
        for (const key in value) {
          this.patchStateStep(key, {...step, value: value[key]});
        }
      }
      else {
        const [key, substep] = StateSynchronizer.nextStep(step);
        this.patchStateStep(key, {...substep, value: substep.value});
      }
    }
  }

  patchStateStep(key, step) {
    if (!(key in this)) {
      return;
    }
    if (this[key] instanceof Synchronized) {
      this[key].patchState([step]);
    }
    else {
      this[key] = step.value;
    }
  }

  tick(elapsed) {
    for (const key of this.synchronizedChildren()) {
      if (this[key] instanceof Synchronized) {
        this[key].tick(elapsed);
        this.state = this.state.set(key, this[key].state);
      }
      else {
        this.state = this.state.set(key, this[key]);
      }
    }

  }

}