aretherecookies-mobile/js/streams/FoodItemsStream.js

//@flow
import FoodItemRecord, { createFoodItem } from '../records/FoodItemRecord';
import { setById } from '../helpers/ImmutableHelpers';
import { Map } from 'immutable';
import location$ from './LocationStream';
import { getFoodItems, type FoodItemsForLocation } from '../apis/FoodItemsApi';
import Filter$ from './FilterStream';
import FilterRecord from '../records/FilterRecord';
import Quantity$ from './QuantityStream';
import type { QuantityFragment } from '../constants/QuantityConstants';

export default location$
	.combineLatest(Filter$)
	.mergeMap(([loc, filter]: [Position, FilterRecord]) => getFoodItems({ loc, filter }))
	.map(({ fooditems = [] }: FoodItemsForLocation) => {
		return fooditems.map(createFoodItem).reduce(setById, new Map());
	})
	.combineLatest(
		Quantity$,
		(foodItems: Map<string, FoodItemRecord>, quantities: Map<string, QuantityFragment>) => {
			return foodItems.mergeDeepWith((foodItem, quantity) => foodItem.merge(quantity), quantities);
		}
	);