// Save custom user data in Firestore
  private updateUserData(user: any) {
    const userRef: AngularFirestoreDocument<any> = this.afs.doc(
      `users/${user.uid}`
    );

    const data = {
      uid: user.uid,
      email: user.email || null,
      displayName: user.displayName || new Chance().name({ prefix: true }),
      photoURL: user.photoURL || "https://goo.gl/7kz9qG"
    };
    return userRef.set(data, { merge: true });
  }

  // Sets user data to firestore after succesful login
  private updateUserData(user) {

    const userRef: AngularFirestoreDocument<User> = this.afs.doc(`users/${user.uid}`);

    console.log(userRef);

    const data: User = {
      uid: user.uid,
      email: user.email || null,
      displayName: user.displayName || 'nameless user',
      photoURL: user.photoURL || 'https://goo.gl/Fz9nrQ'
    }

    return userRef.set(data)

  }

   getInventoryItem(id: string): Observable<InventoryItem>{
     this.inventoryItemDoc = this.afs.doc<InventoryItem>(`inventory_items/${id}`);
     this.inventoryItem = this.inventoryItemDoc.snapshotChanges().map(action =>{
        if(action.payload.exists === false){
          return null;
        }
        else{
          const data = action.payload.data() as InventoryItem;
          data.id = action.payload.id;
          return data;
        }
     });

     return this.inventoryItem;  
   }

getPayment(id: string): Observable < Payment > {
  this.paymentDoc = this.afs.doc<Payment>(`payments/${id}`);
  this.payment = this.paymentDoc.snapshotChanges().map(action => {
    if (action.payload.exists === false) {
      return null;
    }
    else {
      const data = action.payload.data() as Payment;
      data.id = action.payload.id;
      return data;
    }
  });

  return this.payment;
}

   getCustomer(id: string): Observable<Customer>{
     this.customerDoc = this.afs.doc<Customer>(`customers/${id}`);
     this.customer = this.customerDoc.snapshotChanges().map(action =>{
        if(action.payload.exists === false){
          return null;
        }
        else{
          const data = action.payload.data() as Customer;
          data.id = action.payload.id;
          return data;
        }
     });

     return this.customer;  
   }

  deleteInventoryItem(inventoryItem: InventoryItem){
   this.inventoryItemDoc = this.afs.doc(`inventory_items/${inventoryItem.id}`);
   this.inventoryItemDoc.delete();
 }

  //Method to retrieve a post from firestore
  getPost(postId){
    this.postDoc = this.afs.doc('posts/'+postId);
    this.singlePost = this.postDoc.valueChanges();
}

  deleteCustomer(customer: Customer){
   this.customerDoc = this.afs.doc(`customers/${customer.id}`);
   this.customerDoc.delete();
 }