import extend from 'extend';
import Loki from 'loki';

import PowerDatum from './power_datum';
import EnergyDatum from './energy_datum';
import PowerDataApi from './../api/power_data';
import EnergyDataApi from './../api/energy_data';
import HousesApi from './../api/houses';
import ArrayUtil from './../../shared/utils/array'
import MathUtil from './../../shared/utils/math'

class House {

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

  get scoped_id(){
    return `house-${this.data.id}`;
  }

  save(){
    var house = this;
    return House.collection()
      .then((house_collection)=>{
        return house_collection.update(house.data);
      })
  }

  ensurePowerData(opts){
    opts = extend({
      start_date: undefined,
      end_date: undefined
    }, opts || {});
    var house = this,
      query_ranges = DateUtil.dateOverlaps([opts.start_date, opts.end_date], house.data.query_dates]);



    house.collection(PowerDatum.name, {})
      .then((power_collection)=>{

      })
  }

  getPowerData(params){
    var house = this;
    params.house_id = house.data.id;
    return PowerDataApi.index(params).then((power_data)=>{
      return power_data.map((power_datum_data)=>{
        // save new power data into db
        // update mins and maxes.
        var power_datum = PowerDatum.updateOrInitialize(power_datum_data, house);
        house.power_data_collection.set(power_datum.data.time, power_datum);
        house.power_data.push(power_datum);
        return power_datum;
      });
    });
  }

  ensureEnergyData(opts){
    opts = extend({
      start_date: undefined,
      end_date: undefined
    }, opts || {});
    var house = this,
      date_range = Array.from(house.energy_data_store.keys()),
      min_date = Math.min(date_range),
      max_date = Math.max(date_range),
      query_ranges, cache;

    if (date_range.length === 0) return house.getEnergyData({dates: [[opts.start_date, opts.end_date]]})

    query_ranges = MathUtil.minusRange([opts.start_date, opts.end_date], [min_date, max_date]);

    if (!query_ranges) return Promise.resolve(house.power_data);

    cache = ArrayUtil.selectMap(date_range, (datum_day)=>{
      return ArrayUtil.all(query_ranges, (query_range)=>{
        return !MathUtil.inRange(datum_day, query_range);
      });
    }, (datum_day)=>{
      return house.energy_data_store.get(datum_day);
    });

    if (query_ranges.length > 0){
      return house.getEnergyData({dates: query_ranges}).then((new_energy_data)=>{
        return new_energy_data_store.concat(cache);
      });
    } else return Promise.resolve(cache);
  }

  getEnergyData(params){
    var house = this;
    params.house_id = house.data.id;
    return EnergyDataApi.index(params).then((energy_data)=>{
      return energy_data.map((energy_datum_data)=>{
        var energy_datum = EnergyDatum.updateOrInitialize(energy_datum_data, house);
        house.energy_data_store.set(energy_datum.day, energy_datum);
        house.energy_data.push(energy_datum);
        return energy_datum;
      });
    });
  }

  update(data){
    var house = this;
    extend(house.data, data);
  }

  static updateOrInitialize(id, data){
    var house = PowerDatum.store.get(id);
    if (house) house.update(data);
    return house || new House(data, data)
  }

  static accessDb(){
    return new Promise((fnResolve, fnReject){
      if (!House.db) {
        House.db = new Loki('houses', adapter: '');
        House.db.loadDatabase({}, ()=>{
          fnResolve(House.db);
        });
      } else { fnResolve(House.db); }
    });
  }

  static closeDb(){
    if (House.db){
      House.db.save();
      House.db.close();
      House.db = undefined;
    }
  }

  static collection(){
    return House.accessDb()
      .then((db)=>{
        var house_collection = db.getCollection('houses')
        if (!house_collection){
          house_collection = db.addCollection('houses', {indices: ['id']});
        }
        return house_collection;
      });
  }

  static ensureHouses(ids){
    House.collection()
      .then((house_collection)=>{
        houses = house_collection.find({id: {$in: ids}});
        if (houses.length !== ids.length){
          required_ids = ArrayUtil.diff(ids, houses.map((house)=>{ return house.id; }));
          return House.getHouses(required_ids)
            .then((required_houses){
              return houses.concat(required_houses);
            });
        } else { return houses; }
      }).then((house_data)=>{
        return houses_data.map((house_data)=>{ return new House(house_data); })
      });
  }

  static getHouses(ids){
    return HousesApi.index({id: ids})
      .then((houses_data)=>{
        return House.collection()
          .then((house_collection)=>{
            houses_data.forEach((house_data)=>{
              house_collection.insert(house_data);
            });
            return houses_data;
          });
      });
  }

}

export default House;