import { Product } from '../product/product';

import * as _ from 'lodash';
import * as moment from 'moment';


export class Offer {
  public discountRate:     number  = 0;         // Discount percent in range (0,1), initialised when product is set
  public product:          Product = undefined; // Optional assisting attribute to refer to related Product obj

  static createDummyOffer(): Offer {
    let dummyOffer = new Offer(
        '__DUMMY__'
        , '__DUMMY__'
        , '__DUMMY__'
        , '__DUMMY__'
        , '__DUMMY__'
        , '__DUMMY__'
        , '__DUMMY__'
        , -1
        , '__DUMMY__'
        , moment('1970-01-01T00:00:00')
    );
    return dummyOffer;
  }

  static fromJson(obj: any): Offer {
    let _id:              string = (obj.id)           ? obj.id          : '__FALLBACK__';
    let _tenantId:        string = (obj.tenantId)     ? obj.tenantId    : '__FALLBACK__';
    let _customerId:      string = (obj.customerId)   ? obj.customerId  : '__FALLBACK__';
    let _price:           number = (obj.price)        ? obj.price       : -1;
    let _name:            string = (obj.name)         ? obj.name        : '__FALLBACK__';
    let _description:     string = (obj.description)  ? obj.description : '__FALLBACK__';
    let _img_url:         string = (obj.img_url)      ? obj.img_url     : '__FALLBACK__';
    let _productId:       string = (obj.productId)    ? obj.productId   : '__FALLBACK__';
    let _storeId:         string = (obj.storeId)      ? obj.storeId     : '__FALLBACK__';
    let _created:  moment.Moment = (obj.created)      ? obj.created     : moment('1970-01-01T00:00:00');

    // TODO return error and handle it visually if api response not compatible
    return new Offer(_id, _tenantId, _customerId, _storeId, _productId, _name, _description, _price, _img_url, _created );
  }

  // Pushes @offer in @offers only if it isn't already in @offers
  static pushOfferIfUnique(offerToPush: Offer, offers: Offer[]) {
    let foundOffer: Offer = _.find(offers, (o: Offer) => { return o.getOfferId() === offerToPush.getOfferId(); });
    if (!foundOffer) { offers.push(offerToPush); }
  }

  static updateOrPushOffer(offerToUpdate: Offer, offers: Offer[]) {
    let indexOfItemToUpdate = _.findIndex(offers, (o: Offer) => {
      return o.getOfferId() === offerToUpdate.getOfferId();
    });
    if (indexOfItemToUpdate !== -1) {
      offers[indexOfItemToUpdate] = offerToUpdate;
    } else if (indexOfItemToUpdate === -1) {
      offers.push(offerToUpdate);
      console.warn('Warning: Former version of updated offer was not found in local cache, but cache was synced anyway.');
    }
  }

  static deleteOffer(offerToDelete: Offer, offers: Offer[]) {
    let indexOfItemToDelete = _.findIndex(offers, (o: Offer) => {
      return o.getOfferId() === offerToDelete.getOfferId();
    });
    if (indexOfItemToDelete !== -1) {
      offers.splice(indexOfItemToDelete, 1);
    } else if (indexOfItemToDelete === -1) {
      console.warn('Warning: Former version of deleted offer not found in local cache.');
    }
  }

  constructor (
      public offerId:            string
      , public tenantId:         string
      , public customerId:       string
      , public storeId:          string
      , public productId:        string
      , public name:             string
      , public description:      string
      , public discountedPrice:  number // Must be in range (0,1)
      , public img_url:          string
      , public created:          moment.Moment
    ) {}

  getOfferId            () { return this.offerId;         }
  getTenantId           () { return this.tenantId;        }
  getCustomerId         () { return this.customerId;       }
  getStoreId            () { return this.storeId;         }
  getProductName        () { return this.name;            }
  getProductDescription () { return this.description;     }
  getProductImgUrl      () { return this.img_url;         }
  getCreationDate       () { return this.created;         }
  getProduct            () { return this.product;         }
  getProductId          () { return this.productId;       }
  getDiscountRate       () { return this.discountRate;    }
  getDiscountedPrice    () { return this.discountedPrice; }

  setProduct (prod: Product) {
    this.product = prod;
    this.discountRate = Math.abs( (this.discountedPrice - prod.getPrice()) / (prod.getPrice()) );
  }

}