फायरस्टोर डेटाबेस वैल्यू को सही तरीके से कैसे अपडेट करें

मैं अपने स्पंदन एप्लिकेशन में बुनियादी खरीदारी कार्यों का निर्माण करने के लिए काम कर रहा हूँ। मैं कोडिंग और स्पंदन के लिए नया हूँ। जब उपयोगकर्ता AddOrderDetails() विधि को चेक आउट करने की पुष्टि करने के लिए PlaceOrderPageContainer (बटन) पर क्लिक करता है, जो तब फायरबेस डेटाबेस को अपडेट करता है। शॉपिंग कार्ट में कुल राशि की परवाह किए बिना शून्य के रूप में जोड़ी जा रही कुल राशि के अलावा सब कुछ फायरस्टोर डेटाबेस में सही ढंग से अपडेट हो रहा है। मुझे कंसोल में कोई त्रुटि नहीं मिल रही है लेकिन यह स्पष्ट है कि मेरा कोड सही ढंग से नहीं लिखा गया है। किसी भी प्रकार की सहायता सराहनीय होगी। अगर यह मददगार होगा तो मैं कोई अतिरिक्त कोड जोड़ सकता हूं।

    class ShoppingCartPage extends StatefulWidget {
  const ShoppingCartPage({Key? key}) : super(key: key);

  @override
  _ShoppingCartPageState createState() => _ShoppingCartPageState();
}

class _ShoppingCartPageState extends State<ShoppingCartPage> {
  late double totalAmount;

  @override
  void initState() {
    super.initState();
    totalAmount = 0;
    Provider.of<TotalAmountProvider>(
      context,
      listen: false,
    ).display(0);
  }

  @override
  Widget build(BuildContext context) {
    return Consumer2<TotalAmountProvider, CartItemCounterProvider>(
      builder: (context, amountProvider, cartProvider, c) {
        return SafeArea(
          child: Scaffold(
            appBar: const ShoppingCartAppBar(),
            floatingActionButton: FloatingActionButton.extended(
              onPressed: () {
                if (ShoppingApp.sharedPreferences
                        .getStringList(
                          ShoppingApp.userCartList,
                        )
                        ?.length ==
                    1) {
                  Fluttertoast.showToast(msg: ToastString.cartEmpty);
                } else {
                  Navigator.push(
                    context,
                    MaterialPageRoute(
                      builder: (context) => AddressPage(
                        totalAmount: totalAmount,
                      ),
                    ),
                  );
                }
              },
              icon: const Icon(
                Icons.navigate_next,
              ),
              label: Text(
                ButtonString.checkOut.toUpperCase(),
              ),
            ),
            body: CustomScrollView(
              slivers: [
                SliverToBoxAdapter(
                  child:
                      Consumer2<TotalAmountProvider, CartItemCounterProvider>(
                    builder: (context, amountProvider, cartProvider, c) {
                      return Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: Center(
                          child: cartProvider.count == 0
                              ? Container()
                              : Text(
                                  'Total Price: \$${amountProvider.totalAmount.toString()}',
                                  style: Theme.of(context).textTheme.headline6,
                                ),
                        ),
                      );
                    },
                  ),
                ),
                StreamBuilder<QuerySnapshot>(
                    stream: ShoppingApp.firestore
                        .collection('items')
                        .where('shortInfo',
                            whereIn: ShoppingApp.sharedPreferences
                                .getStringList(ShoppingApp.userCartList))
                        .snapshots(),
                    builder: (context, AsyncSnapshot snapshot) {
                      return !snapshot.hasData
                          ? const AdaptiveCircularProgressSliver()
                          : snapshot.data.docs.isEmpty
                              ? const EmptyShoppingCartContainer()
                              : SliverList(
                                  delegate: SliverChildBuilderDelegate(
                                    (context, index) {
                                      ItemModel model = ItemModel.fromJson(
                                        snapshot.data.docs[index].data(),
                                      );
                                      if (index == 0) {
                                        totalAmount = 0;
                                        // totalAmount = model.price! + totalAmount;
                                      } else {
                                        totalAmount =
                                            model.price! + totalAmount;
                                      }
                                      if (snapshot.data?.docs.length - 1 ==
                                          index) {
                                        WidgetsBinding.instance!
                                            .addPostFrameCallback((timeStamp) {
                                          Provider.of<TotalAmountProvider>(
                                                  context,
                                                  listen: false)
                                              .display(totalAmount);
                                        });
                                      }
                                      return sourceInfo(
                                        model,
                                        context,
                                        removeCartFunction: () =>
                                            removeItemFromUserCart(
                                          model.shortInfo as String,
                                        ),
                                      );
                                    },
                                    childCount: snapshot.hasData
                                        ? snapshot.data?.docs.length
                                        : 0,
                                  ),
                                );
                    }),
              ],
            ),
          ),
        );
      },
    );
  }

  Future<void> removeItemFromUserCart(
    String shortInfoAsID,
  ) async {
    List<String>? tempCartList = ShoppingApp.sharedPreferences.getStringList(
      ShoppingApp.userCartList,
    );
    tempCartList?.remove(shortInfoAsID);

    await ShoppingApp.firestore
        .collection(ShoppingApp.collectionUser)
        .doc(ShoppingApp.sharedPreferences.getString(
          ShoppingApp.userUID,
        ))
        .update({
      ShoppingApp.userCartList: tempCartList,
    }).then((value) {
      Fluttertoast.showToast(
        msg: ToastString.removeFromCart,
      );
      ShoppingApp.sharedPreferences.setStringList(
        ShoppingApp.userCartList,
        tempCartList as List<String>,
      );

      Provider.of<CartItemCounterProvider>(
        context,
        listen: false,
      ).displayResult();

      totalAmount = 0;
    });
  }
}

class AddressPage extends StatefulWidget {
  const AddressPage({
    Key? key,
    required this.totalAmount,
  }) : super(key: key);

  final double totalAmount;

  @override
  _AddressPageState createState() => _AddressPageState();
}

class _AddressPageState extends State<AddressPage> {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: AdaptiveLayoutScaffold(
        appBar: const AddressPageAppBar(),
        floatingActionButton: const AddNewAddressFAB(),
        landscapeBodyWidget: Container(),
        portraitBodyWidget: Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          mainAxisSize: MainAxisSize.min,
          children: [
            const AddressPageHeadline(
              headlineText: ShoppingPageString.selectAddress,
            ),
            Consumer<AddressChangerProvider>(builder: (
              context,
              address,
              c,
            ) {
              return Flexible(
                child: StreamBuilder<QuerySnapshot>(
                    stream: ShoppingApp.firestore
                        .collection(ShoppingApp.collectionUser)
                        .doc(ShoppingApp.sharedPreferences
                            .getString(ShoppingApp.userUID))
                        .collection(ShoppingApp.subCollectionAddress)
                        .snapshots(),
                    builder: (context, snapshot) {
                      return !snapshot.hasData
                          ? const AdaptiveCircularProgressCenter()
                          : snapshot.data!.docs.isEmpty
                              ? const EmptyShippingAddressContainer()
                              : ListView.builder(
                                  itemCount: snapshot.data?.docs.length,
                                  shrinkWrap: true,
                                  itemBuilder: (context, index) {
                                    return AddressCard(
                                      addressID: snapshot.data?.docs[index].id
                                          as String,
                                      currentIndex: address.count,
                                      model: AddressModel.fromJson(
                                        snapshot.data?.docs[index].data()
                                            as Map<String, dynamic>,
                                      ),
                                      totalAmount: widget.totalAmount,
                                      value: index,
                                    );
                                  },
                                );
                    }),
              );
            }),
          ],
        ),
      ),
    );
  }
}

class AddressCard extends StatefulWidget {

  const AddressCard({
    Key? key,
    required this.addressID,
    required this.currentIndex,
    required this.model,
    required this.totalAmount,
    required this.value,
  }) : super(key: key);

  final String addressID;
  final int currentIndex;
  final AddressModel model;
  final double totalAmount;
  final int value;

  @override
  _AddressCardState createState() => _AddressCardState();
}

class _AddressCardState extends State<AddressCard> {
  @override
  Widget build(BuildContext context) {
    return AddressCardContainer(
      onTap: () {
        Provider.of<AddressChangerProvider>(
          context,
          listen: false,
        ).displayResult(widget.value);
      },
      addressCardColumn: AddressCardColumn(
        children: [
          Row(
            children: [
              AddressCardRadioButton(
                groupValue: widget.currentIndex,
                onChanged: (value) {
                  Provider.of<AddressChangerProvider>(
                    context,
                    listen: false,
                  ).displayResult(
                    value as int,
                  );
                },
                value: widget.value,
              ),
              AddressCardContent(
                city: widget.model.city as String,
                fullName: widget.model.name as String,
                phoneNumber: widget.model.phoneNumber as String,
                postalCode: widget.model.postalCode as String,
                state: widget.model.state as String,
                streetAddress: widget.model.streetAddress as String,
              ),
            ],
          ),
          widget.value == Provider.of<AddressChangerProvider>(context).count
              ? ShippingAddressProceedButton(
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (
                          context,
                        ) =>
                            PlaceOrderPaymentPage(
                          addressID: widget.addressID,
                          totalAmount: widget.totalAmount,
                        ),
                      ),
                    );
                  },
                )
              : Container(),
        ],
      ),
    );
  }
}

class PlaceOrderPaymentPage extends StatefulWidget {
  const PlaceOrderPaymentPage({
    Key? key,
    required this.addressID,
    required this.totalAmount,
  }) : super(key: key);

  final String addressID;
  final double totalAmount;

  @override
  _PlaceOrderPaymentPageState createState() => _PlaceOrderPaymentPageState();
}

class _PlaceOrderPaymentPageState extends State<PlaceOrderPaymentPage> {
  @override
  Widget build(BuildContext context) {
    return AdaptiveLayoutScaffold(
      appBar: const PlaceOrderPaymentPageAppBar(),
      landscapeBodyWidget: Container(),
      portraitBodyWidget: PlaceOrderPageContainer(
        orderOnPressed: () => addOrderDetails(),
      ),
    );
  }

  void addOrderDetails() {
    final time = DateTime.now().millisecondsSinceEpoch;

    writeOrderDetailsForUser({
      ShoppingApp.addressID: widget.addressID,
      ShoppingApp.totalAmount: widget.totalAmount,
      'orderBy': ShoppingApp.sharedPreferences.getString(
        ShoppingApp.userUID,
      ),
      ShoppingApp.productID: ShoppingApp.sharedPreferences.getStringList(
        ShoppingApp.userCartList,
      ),
      ShoppingApp.paymentDetails: ShoppingPageString.cashOnDelivery,
      ShoppingApp.orderTime: time.toString(),
      ShoppingApp.isSuccess: true,
    });

    writeOrderDetailsForAdmin({
      ShoppingApp.addressID: widget.addressID,
      ShoppingApp.totalAmount: widget.totalAmount,
      'orderBy': ShoppingApp.sharedPreferences.getString(
        ShoppingApp.userUID,
      ),
      ShoppingApp.productID: ShoppingApp.sharedPreferences.getStringList(
        ShoppingApp.userCartList,
      ),
      ShoppingApp.paymentDetails: ShoppingPageString.cashOnDelivery,
      ShoppingApp.orderTime: time.toString(),
      ShoppingApp.isSuccess: true,
    }).whenComplete(() => {
          emptyCartNow(),
        });
  }

  void emptyCartNow() {
    ShoppingApp.sharedPreferences.setStringList(ShoppingApp.userCartList, [
      'garbageValue',
    ]);
    List<String>? tempList = ShoppingApp.sharedPreferences.getStringList(
      ShoppingApp.userCartList,
    );

    FirebaseFirestore.instance
        .collection('users')
        .doc(ShoppingApp.sharedPreferences.getString(
          ShoppingApp.userUID,
        ))
        .update({
      ShoppingApp.userCartList: tempList,
    }).then((value) {
      ShoppingApp.sharedPreferences.setStringList(
        ShoppingApp.userCartList,
        tempList as List<String>,
      );
      Provider.of<CartItemCounterProvider>(
        context,
        listen: false,
      ).displayResult();
    });
    Fluttertoast.showToast(
      msg: ToastString.orderPlacedSuccessfully,
    );
    Navigator.pushReplacement(
      context,
      MaterialPageRoute(
        builder: (context) => const ShoppingPage(),
      ),
    );
  }

  Future<void> writeOrderDetailsForUser(
    Map<String, dynamic> data,
  ) async {
    await ShoppingApp.firestore
        .collection(ShoppingApp.collectionUser)
        .doc(ShoppingApp.sharedPreferences.getString(ShoppingApp.userUID))
        .collection(ShoppingApp.collectionOrders)
        .doc(
          ShoppingApp.sharedPreferences.getString(ShoppingApp.userUID)! +
              data['orderTime'],
        )
        .set(data);
  }

  Future<void> writeOrderDetailsForAdmin(Map<String, dynamic> data) async {
    await ShoppingApp.firestore
        .collection(ShoppingApp.collectionOrders)
        .doc(
          ShoppingApp.sharedPreferences.getString(ShoppingApp.userUID)! +
              data['orderTime'],
        )
        .set(data);
  }
}


class CartItemCounterProvider extends ChangeNotifier {
  final int _counter = (ShoppingApp.sharedPreferences
              .getStringList(
                ShoppingApp.userCartList,
              )
              ?.length ??
          0) -
      1;
  int get count => _counter;

  Future<void> displayResult() async {
    
    int _counter = (ShoppingApp.sharedPreferences
                .getStringList(
                  ShoppingApp.userCartList,
                )
                ?.length ??
            0) -
        1;

    await Future.delayed(
        const Duration(
          milliseconds: 100,
        ), () {
      notifyListeners();
    });
  }
}