house.js

// databasable.js

import Loki from 'lokijs/src/lokijs';
import LokiIndexedAdapter from 'lokijs/src/loki-indexed-adapter';

const DEFAULTS = {
  autosave: false
};

var databasable = {

  accessDb: function(db_name){
    var databasable = this,
      opts = Object.assign({
        adapter: new LokiIndexedAdapter(db_name)
      }, DEFAULTS, databasable.lokijs_options || {}),
      has_adapter = !!opts.adapter;
    return new Promise((fnResolve, fnReject)=>{
      if (!databasable.db) {
        databasable.db = new Loki(db_name, opts);
        if (has_adapter){
          databasable.db.loadDatabase({}, ()=>{
            fnResolve(databasable.db);
          });
        } else { fnResolve(databasable.db); }
      } else { fnResolve(databasable.db); }
    });
  },

  closeDb: function(){
    var databasable = this;
    if (databasable.db){
      databasable.db.save();
      databasable.db.close();
      databasable.db = undefined;
    }
  },

  collection: function(db_name, collection_name, options){
    var databasable = this;
    options = options || {};
    return databasable.accessDb(db_name)
        .then((db)=>{
          if (!db || db !== databasable.db){
            throw new Error('Databasable does not have db set.')
          }
          var collection = db.getCollection(collection_name)
          if (!collection){
            collection = db.addCollection(collection_name, options);
            if (options && options.unique_indices){
              options.unique_indices.forEach((field)=>{
                collection.ensureUniqueIndex(field);
              });
            }
          }
          return collection;
        });
  }
}

// house.js
class House {

  // must be initiated with a dataset already in Loki database (not directly JSON).
  constructor(data){
    var house = this;
    house.data = data;
    house.state = {};
    Object.assign(house, Databasable);
  }

  setEnergyData(energy_range){
    var house = this;
    house.state.energy_range = energy_range;
    return house.collection(house.scoped_id, EnergyDatum.NAME, EnergyDatum.COLLECTION_OPTIONS)
      .then((energy_collection)=>{
        return house.ensureEnergyData()
          .then((res)=>{
            console.log(res) // Promise {[[PromiseStatus]]: "pending", [[PromiseValue]]: undefined}
            var params = house.rangeToLokiParams('day', house.state.energy_range);
            // and House#saveEnergyData has not finished - no data retrived from LokiJs database.
            house.energy_data = energy_collection.find(params)
                  .sort((pd1, pd2)=>{
                    if (pd1.day === pd2.day) return 0;
                    if (pd1.day > pd2.day) return 1;
                    if (pd1.day < pd2.day) return -1;
                  })
                  .map((data)=>{ return new EnergyDatum(data, house); });
          });
      });
  }
    
  ensureEnergyData(){
    var house = this,
      query_ranges = DateRange.addRange(house.state.energy_range, house.data.energy_datum_ranges || []);
    if (query_ranges.gaps_filled.length > 0){
      return house.getEnergyData({dates: query_ranges.gaps_filled})
          .then((energy_data)=>{
            return house.saveEnergyData(energy_data, query_ranges.new_ranges)
          });
    } else { return Promise.resolve(); }
  }
  
  getEnergyData(params){
    return jQuery.ajax({url: 'yada.com/action', type: 'POST', data: params})
        .then((res)=>{ return res.data });
  }
    
  // save new energy data to LokiJs Db, as well as
  // the new energy data query ranges (ie house metadata).
  saveEnergyData(energy_data, new_ranges){
    var house = this;
    return house.collection(house.scoped_id, EnergyDatum.NAME, EnergyDatum.COLLECTION_OPTIONS)
        .then((energy_collection)=>{
          energy_collection.insert(energy_data);
          house.db.save();
          house.data.energy_datum_ranges = new_ranges;
          house.save();
        });
  }