import {arrayUnique, flatten, mapObject} from '@avocado/core';
import memoize from 'lodash.memoize';
import {invokeHookFlat, registerHooks} from 'scwp';

export const globals = memoize(() => (
  invokeHookFlat('behaviorContextGlobals')
    .reduce((r, results) => ({
      ...r,
      ...results,
    }), {})
));

export default class Context {

  constructor(defaults = {}) {
    this.map = new Map();
    this.clear();
    this.addObjectMap(defaults);
  }

  add(key, value, type = 'undefined') {
    if (key) {
      this.map.set(key, [value, type]);
    }
  }

  addObjectMap(map) {
    Object.entries(map)
      .forEach(([key, [variable, type]]) => (
        this.add(key, variable, type)
      ));
  }

  all() {
    return Array.from(this.map.keys())
      .reduce((r, key) => ({
        ...r,
        [key]: this.get(key),
      }), {});
  }

  clear() {
    this.destroy();
    this.add('context', this, 'context');
    this.addObjectMap(globals());
  }

  description() {
    const children = Object.entries(this.all())
      .reduce((r, [key, [, type]]) => ({
        ...r,
        [key]: {type},
      }), {});
    return {
      children,
      type: 'context',
    };
  }

  destroy() {
    this.map.clear();
  }

  get(key) {
    return this.has(key) ? this.map.get(key) : [undefined, 'undefined'];
  }

  getValue(key) {
    return this.get(key)[0];
  }

  getType(key) {
    return this.get(key)[1];
  }

  has(key) {
    return this.map.has(key);
  }

}

registerHooks({
  autoreg$accept: (type, M) => {
    if ('hooks' === type && 'behaviorContextGlobals' in M) {
      globals.cache.clear();
    }
  },
}, module.id);