Meus primeiros passos com Firestore

data-model.ts

import { Address } from 'ngx-google-places-autocomplete/objects/address';

export interface Price {
    value: number
    date: Date
    place?: Address
    url?: URL
}

export interface Measurement {
    value: number
    unit: string
}

export interface Packaging {
    barcode: number
    measurement: Measurement
    price: Price[]
}

export interface Product {
    id: number
    name: string
    brand?: string
    manufacturer?: string
    packaging: Packaging[]
}

data.json

{
    "products": [
        {
            "id": 1,
            "name": "Achocolatado",
            "brand": "Nescau",
            "manufacturer": "Nestlé",
            "packaging": [
                {
                    "barcode": 7891000372401,
                    "measurement": { "value": 3, "unit": "kg" },
                    "price": [
                        {
                            "value": 57.81,
                            "date": 1521412653726,
                            "url": "https://www.ndays.com.br/nescau-caixa-3x3kg?gclid=CjwKCAjwnLjVBRAdEiwAKSGPI2z3axTioMSx_TLG1NgZ62TCMO_yBj-2-gUe8MHL9-tV4DOAU51QCRoCMywQAvD_BwE",
                            "place": null
                        }
                    ]
                }
            ]
        }
        ]
}

product.service.ts

import { Injectable } from '@angular/core';
import { AngularFirestore, AngularFirestoreCollection } from 'angularfire2/firestore';
import { Observable } from 'rxjs/Observable';

import { Product } from './data-model';

@Injectable()
export class ProductService {
  protected ref: string = 'products';
  protected collection: AngularFirestoreCollection<Product>;

  constructor(
    private db: AngularFirestore
  ) { }

  getProducts(): Observable<Product[]> {
    this.collection = this.db.collection<Product>(this.ref);
    return this.collection.snapshotChanges().map(
      actions => {
        return actions.map(a => {
          const data = a.payload.doc.data() as Product;
          const id = a.payload.doc.id;
          return { id, ...data };
        })
      }
    );
  }

  getProduct(id: any) {
    return false;
  }

}