public getDbAllCars() {
    const companyCollection = this.afs.collection<Company>(AuthService.COMPANY_COLLECTION_NAME);
    return companyCollection.snapshotChanges().pipe(
        map(actions => {
            return actions.map(a => {
              const data = a.payload.doc.data();
              const id = a.payload.doc.id;
              return { id, ...data };
            });
        }),
        map(companies => {
            return companies.map(company => {
              console.log(company.id);
              return this.getCars(company.id).subscribe();
            });
        }),
        tap(companies => {
            console.log(companies);
        }),
    );
  }
  
  下面兩個function 是摳過來的
  

  getCars(companyId: string) {
    const carsCollection = this.afs.collection<Car>(`${AuthService.COMPANY_COLLECTION_NAME}/${companyId}/${AuthService.CAR_COLLECTION_NAME}`);
    return carsCollection.snapshotChanges().pipe(
      map(actions => {
        return actions.map(a => {
          const data = a.payload.doc.data();
          const id = a.payload.doc.id;
          return { id, ...data };
        });
      }),
      map(cars => {
        return cars.map(car => {
          car.pictures = this.getCarPicture(companyId, car.id);
          return car;
        });
      }),
      tap(cars => {
        console.log('[getCars: Car Service] Cars get');
        console.log(cars);
      }),
    );
  }

  getCarPicture(companyId: string, carId: string) {
    const carPicturesCollection = this.afs.collection<CarPicture>(`${AuthService.COMPANY_COLLECTION_NAME}/${companyId}/${AuthService.CAR_COLLECTION_NAME}/${carId}/${AuthService.CAR_PICTURE_COLLECTION_NAME}`,
      ref => ref.where('order', '==', 0));
    return carPicturesCollection.snapshotChanges().pipe(
      map(actions => {
        return actions.map(a => {
          const data = a.payload.doc.data();
          const id = a.payload.doc.id;
          data.image = this.storage.ref(data.image).getDownloadURL();
          return { id, ...data };
        });
      }),
      tap(carPictures => {
        console.log('[Car Service] Car pictures get');
        console.log(carPictures);
      }),
    );
  }