import Ember from 'ember';
import _ from 'lodash';
import store from 'corpus-common-addon/utils/store';

const DEFAULT_DEBOUNCE = 10;

export default Ember.Service.extend({

  promises: null,
  queryRegister: null,

  storeKeyBase: null,
  apiPath: null,
  resDocRoot: null,

  processId: function (id) {
    return id;
  },

  getReturnDictKey: function (id) {
    return id;
  },

  init(...args) {
    this._super(...args);
    this.set('promises', []);
    this.set('queryRegister', {});
    this.doQuery = _.debounce(this._doQuery, DEFAULT_DEBOUNCE);
  },

  env: function () {
    return Ember.getOwner(this).resolveRegistration('config:environment');
  },


  _getStoreKey: function (id) {
    return this.storeKeyBase + ':' + id;
  },

  _doQuery: function () {
    const queryRegister = this.get('queryRegister');

    this.set('queryRegister', {});

    const ids = Object.keys(queryRegister).join(',');

    if (!ids) {
      _.each(queryRegister, resolveReject=> {
        resolveReject[0]({});
      });
    }
    Ember.$.ajax({
      // TODO Configuration ?
      url: this.env().APP.backRootURL.replace(/\/$/, '') + this.apiPath + ids,

      success: itemDoc=> {
        _.each(queryRegister, resolveReject=> {
          resolveReject[0](itemDoc[this.resDocRoot]);
        });
      },
      error: (req, status, error)=> {
        _.each(queryRegister, resolveReject=> {
          resolveReject[1](status + ':' + error);
        });

      }
    });
  },

  // make the query for the name.
  // return a Promise
  queryName: function (id) {
    const queryRegister = this.get('queryRegister');

    return new Ember.RSVP.Promise(function (resolve, reject) {
      queryRegister[id] = [resolve, reject];
      this.doQuery(this);
    }.bind(this));
  },

  getName: function (id) {

    if (!id) {
      return new Ember.RSVP.Promise(function (resolve/* , reject*/) {
        resolve('');
      });
    }

    const objectId = this.processId(id);

    let namePromise = null;

    const storeKey = this._getStoreKey(id);
    const name = store.get(storeKey);

    if (name !== null) {
      namePromise = new Ember.RSVP.Promise(function (resolve/* , reject*/) {
        resolve(name);
      });
    } else if (storeKey in this.get('promises')) {
      namePromise = this.get('promises')[storeKey];
    } else {
      // handle error !!!
      namePromise = this.queryName(objectId)
        .then(function (names) {
          delete this.get('promises').storeKey; /* eslint prefer-reflect: "off" */

          return store.set(storeKey, names[this.getReturnDictKey(objectId)]);
        }.bind(this));
      this.get('promises')[storeKey] = namePromise;
    }

    return namePromise;
  }

});