hash-wallet/lib/view_model/payment/payment_view_model.dart

import 'dart:async';

import 'package:cake_wallet/core/universal_address_detector.dart';
import 'package:cake_wallet/evm/evm.dart';
import 'package:cake_wallet/reactions/wallet_connect.dart';
import 'package:cake_wallet/solana/solana.dart';
import 'package:cake_wallet/tron/tron.dart';
import 'package:cake_wallet/store/app_store.dart';
import 'package:cw_core/wallet_type.dart';
import 'package:cw_core/wallet_info.dart';
import 'package:cw_core/utils/print_verbose.dart';
import 'package:cw_core/currency_for_wallet_type.dart';
import 'package:cw_core/crypto_currency.dart';
import 'package:mobx/mobx.dart';

part 'payment_view_model.g.dart';

class PaymentViewModel = PaymentViewModelBase with _$PaymentViewModel;

abstract class PaymentViewModelBase with Store {
  PaymentViewModelBase({required this.appStore});

  final AppStore appStore;

  @observable
  WalletType? detectedWalletType;

  @observable
  AddressDetectionResult? _lastDetectionResult;

  @computed
  int? get detectedChainId {
    if (detectedWalletType == null) return null;

    if (!isEVMCompatibleChain(detectedWalletType!)) return null;

    if (_lastDetectionResult?.chainId != null) {
      return _lastDetectionResult!.chainId;
    }

    // If detected wallet type is EVM-compatible, get chainId from detected currency
    if (_lastDetectionResult?.detectedCurrency != null) {
      return getChainIdByCryptoCurrency(_lastDetectionResult!.detectedCurrency!);
    }

    return evm?.getChainIdByWalletType(detectedWalletType!);
  }

  @observable
  bool isProcessing = false;

  @computed
  WalletType get currentWalletType => appStore.wallet!.type;

  @computed
  int? get currentChainId {
    if (!isEVMCompatibleChain(currentWalletType) || evm == null) return null;

    return evm!.getSelectedChainId(appStore.wallet!);
  }

  /// Main entry point - detect address type and check compatibility
  @action
  Future<PaymentFlowResult> processAddress(String addressData) async {
    try {
      detectedWalletType = null;
      isProcessing = true;

      // Detect address type
      final detectionResult = UniversalAddressDetector.detectAddress(addressData);

      _lastDetectionResult = detectionResult;
      detectedWalletType = detectionResult.detectedWalletType;

      if (!detectionResult.isValid || detectedWalletType == null) {
        return PaymentFlowResult.incompatible('Unable to detect address type');
      }

      if (detectedWalletType == WalletType.solana && solana == null) {
        return PaymentFlowResult.incompatible('Solana is not available in this app build.');
      }
      if (detectedWalletType == WalletType.tron && tron == null) {
        return PaymentFlowResult.incompatible('Tron is not available in this app build.');
      }
      if (isEVMCompatibleChain(detectedWalletType!) && evm == null) {
        return PaymentFlowResult.incompatible(
          'Ethereum-compatible addresses are not supported in this app build.',
        );
      }

      final currentWallet = appStore.wallet;

      if (currentWallet != null &&
          currentWallet.type == detectedWalletType &&
          !isEVMCompatibleChain(detectedWalletType!)) {
        return PaymentFlowResult.currentWalletCompatible(detectionResult);
      }

      if (detectedWalletType == WalletType.solana) {
        final compatibleWallets = await getWalletsByType(WalletType.solana);
        return PaymentFlowResult.solanaTokenSelection(
          detectionResult,
          compatibleWallets: compatibleWallets,
          wallet: compatibleWallets.isNotEmpty ? compatibleWallets.first : null,
        );
      }

      if (detectedWalletType == WalletType.tron) {
        final compatibleWallets = await getWalletsByType(WalletType.tron);
        return PaymentFlowResult.tronTokenSelection(
          detectionResult,
          compatibleWallets: compatibleWallets,
          wallet: compatibleWallets.isNotEmpty ? compatibleWallets.first : null,
        );
      }

      if (isEVMCompatibleChain(detectedWalletType!)) {
        return PaymentFlowResult.evmNetworkSelection(detectionResult);
      }

      final compatibleWallets = await getWalletsByType(detectedWalletType!);

      switch (compatibleWallets.length) {
        case 0:
          return PaymentFlowResult.noWallets(detectedWalletType!, detectionResult);
        case 1:
          return PaymentFlowResult.singleWallet(compatibleWallets.first, detectionResult);
        default:
          return PaymentFlowResult.multipleWallets(compatibleWallets, detectionResult);
      }
    } catch (e) {
      printV('PaymentViewModel error: $e');
      return PaymentFlowResult.error('Payment processing failed: $e');
    } finally {
      isProcessing = false;
    }
  }

  @action
  Future<void> selectChain() async {
    if (detectedWalletType == null || evm == null || detectedChainId == null) return;

    final node =
        appStore.settingsStore.getCurrentNode(detectedWalletType!, chainId: detectedChainId);

    await evm!.selectChain(appStore.wallet!, detectedChainId!, node: node);
  }

  Future<List<WalletInfo>> getWalletsByType(WalletType walletType) async {
    return (await WalletInfo.getAll()).where((wallet) => wallet.type == walletType).toList();
  }

  Future<List<WalletInfo>> getEVMCompatibleWallets() async {
    final allWallets = await WalletInfo.getAll();
    return allWallets.where((wallet) => isEVMCompatibleChain(wallet.type)).toList();
  }
}

class PaymentFlowResult {
  final PaymentFlowType type;
  final String? message;
  final WalletInfo? wallet;
  final int? chainId;
  final List<WalletInfo> wallets;
  final WalletType? walletType;
  final AddressDetectionResult? addressDetectionResult;

  PaymentFlowResult._({
    required this.type,
    this.message,
    this.wallet,
    this.chainId,
    this.wallets = const [],
    this.walletType,
    this.addressDetectionResult,
  });

  /// EVM address detected - needs network selection
  /// We'll also take note of the number of compatible wallets for EVM ecosystem
  factory PaymentFlowResult.evmNetworkSelection(
    AddressDetectionResult addressDetectionResult, {
    List<WalletInfo>? compatibleWallets,
    WalletInfo? wallet,
  }) {
    int? chainId = addressDetectionResult.chainId;
    if (chainId == null && addressDetectionResult.detectedCurrency != null) {
      chainId = getChainIdByCryptoCurrency(addressDetectionResult.detectedCurrency!);
    }
    if (chainId == null && addressDetectionResult.detectedWalletType != null) {
      chainId = evm?.getChainIdByWalletType(addressDetectionResult.detectedWalletType!);
    }

    return PaymentFlowResult._(
      type: PaymentFlowType.evmNetworkSelection,
      addressDetectionResult: addressDetectionResult,
      walletType: addressDetectionResult.detectedWalletType,
      chainId: chainId,
      wallets: compatibleWallets ?? [],
      wallet: wallet,
    );
  }

  /// Solana address detected - needs token selection
  factory PaymentFlowResult.solanaTokenSelection(
    AddressDetectionResult addressDetectionResult, {
    List<WalletInfo>? compatibleWallets,
    WalletInfo? wallet,
  }) =>
      PaymentFlowResult._(
        type: PaymentFlowType.solanaTokenSelection,
        addressDetectionResult: addressDetectionResult,
        walletType: WalletType.solana,
        wallets: compatibleWallets ?? [],
        wallet: wallet,
      );

  /// Tron address detected - needs token selection
  factory PaymentFlowResult.tronTokenSelection(
    AddressDetectionResult addressDetectionResult, {
    List<WalletInfo>? compatibleWallets,
    WalletInfo? wallet,
  }) =>
      PaymentFlowResult._(
        type: PaymentFlowType.tronTokenSelection,
        addressDetectionResult: addressDetectionResult,
        walletType: WalletType.tron,
        wallets: compatibleWallets ?? [],
        wallet: wallet,
      );

  /// Current wallet is compatible
  factory PaymentFlowResult.currentWalletCompatible(
          AddressDetectionResult addressDetectionResult) =>
      PaymentFlowResult._(
        type: PaymentFlowType.currentWalletCompatible,
        addressDetectionResult: addressDetectionResult,
      );

  /// Single compatible wallet available
  factory PaymentFlowResult.singleWallet(
    WalletInfo wallet,
    AddressDetectionResult addressDetectionResult,
  ) {
    int? chainId = addressDetectionResult.chainId;
    if (chainId == null && addressDetectionResult.detectedCurrency != null) {
      chainId = getChainIdByCryptoCurrency(addressDetectionResult.detectedCurrency!);
    }
    if (chainId == null) {
      chainId = evm?.getChainIdByWalletType(wallet.type);
    }

    return PaymentFlowResult._(
      type: PaymentFlowType.singleWallet,
      wallet: wallet,
      walletType: wallet.type,
      chainId: chainId,
      addressDetectionResult: addressDetectionResult,
    );
  }

  /// Multiple compatible wallets available
  factory PaymentFlowResult.multipleWallets(
    List<WalletInfo> wallets,
    AddressDetectionResult addressDetectionResult,
  ) {
    int? chainId = addressDetectionResult.chainId;
    if (chainId == null && addressDetectionResult.detectedCurrency != null) {
      chainId = getChainIdByCryptoCurrency(addressDetectionResult.detectedCurrency!);
    }
    if (chainId == null) {
      chainId = evm?.getChainIdByWalletType(wallets.first.type);
    }

    return PaymentFlowResult._(
      type: PaymentFlowType.multipleWallets,
      wallets: wallets,
      walletType: wallets.first.type,
      addressDetectionResult: addressDetectionResult,
      chainId: chainId,
    );
  }

  /// No compatible wallets available
  factory PaymentFlowResult.noWallets(
    WalletType walletType,
    AddressDetectionResult addressDetectionResult,
  ) {
    int? chainId = addressDetectionResult.chainId;
    if (chainId == null && addressDetectionResult.detectedCurrency != null) {
      chainId = getChainIdByCryptoCurrency(addressDetectionResult.detectedCurrency!);
    }
    if (chainId == null) {
      chainId = evm?.getChainIdByWalletType(walletType);
    }

    return PaymentFlowResult._(
      type: PaymentFlowType.noWallets,
      walletType: walletType,
      addressDetectionResult: addressDetectionResult,
      chainId: chainId,
    );
  }

  /// Error occurred
  factory PaymentFlowResult.error(String message) =>
      PaymentFlowResult._(type: PaymentFlowType.error, message: message);

  /// Incompatible address
  factory PaymentFlowResult.incompatible(String message) =>
      PaymentFlowResult._(type: PaymentFlowType.incompatible, message: message);

  CryptoCurrency? get detectedCurrency {
    if (type == PaymentFlowType.evmNetworkSelection ||
        type == PaymentFlowType.solanaTokenSelection ||
        type == PaymentFlowType.tronTokenSelection) {
      return addressDetectionResult?.detectedCurrency;
    }
    if (walletType != null) {
      if (isEVMCompatibleChain(walletType!)) {
        return walletTypeToCryptoCurrency(walletType!, chainId: chainId);
      }

      return walletTypeToCryptoCurrency(walletType!);
    }
    return null;
  }
}

enum PaymentFlowType {
  currentWalletCompatible,
  singleWallet,
  multipleWallets,
  noWallets,
  evmNetworkSelection,
  solanaTokenSelection,
  tronTokenSelection,
  error,
  incompatible,
}