import 'package:flutter/material.dart';

import 'package:collection/collection.dart';

import 'package:uuid/uuid.dart';

import 'package:pshared/api/requests/payment/quote.dart';
import 'package:pshared/data/mapper/payment/intent/payment.dart';
import 'package:pshared/models/asset.dart';
import 'package:pshared/models/payment/currency_pair.dart';
import 'package:pshared/models/payment/customer.dart';
import 'package:pshared/models/payment/fx/intent.dart';
import 'package:pshared/models/payment/fx/side.dart';
import 'package:pshared/models/payment/kind.dart';
import 'package:pshared/models/payment/methods/managed_wallet.dart';
import 'package:pshared/models/payment/methods/type.dart';
import 'package:pshared/models/payment/money.dart';
import 'package:pshared/models/payment/settlement_mode.dart';
import 'package:pshared/models/payment/intent.dart';
import 'package:pshared/models/payment/quote.dart';
import 'package:pshared/models/recipient/recipient.dart';
import 'package:pshared/provider/organizations.dart';
import 'package:pshared/provider/payment/amount.dart';
import 'package:pshared/provider/payment/flow.dart';
import 'package:pshared/provider/payment/wallets.dart';
import 'package:pshared/provider/recipient/provider.dart';
import 'package:pshared/provider/recipient/pmethods.dart';
import 'package:pshared/provider/resource.dart';
import 'package:pshared/service/payment/quotation.dart';
import 'package:pshared/utils/currency.dart';


class QuotationProvider extends ChangeNotifier {
  Resource<PaymentQuote> _quotation = Resource(data: null, isLoading: false, error: null);
  late OrganizationsProvider _organizations;
  bool _isLoaded = false;

  void update(
    OrganizationsProvider venue, 
    PaymentAmountProvider payment,
    WalletsProvider wallets,
    PaymentFlowProvider flow,
    RecipientsProvider recipients,
    PaymentMethodsProvider methods,
  ) {
    _organizations = venue;
    final t = flow.selectedType;
    final method = methods.methods.firstWhereOrNull((m) => m.type == t);
    if ((wallets.selectedWallet != null) && (method != null)) {
      final customer = _buildCustomer(
        recipient: recipients.currentObject,
        method: method,
      );
      final amount = Money(
        amount: payment.amount.toString(),
        // TODO: adapt to possible other sources
        currency: currencyCodeToString(wallets.selectedWallet!.currency),
      );
      final fxIntent = FxIntent(
        pair: CurrencyPair(
          base: currencyCodeToString(wallets.selectedWallet!.currency),
          quote: 'RUB', // TODO: exentd target currencies
        ),
        side: FxSide.sellBaseBuyQuote,
      );
      getQuotation(PaymentIntent(
        kind: PaymentKind.payout,
        amount: amount,
        destination: method.data,
        source: ManagedWalletPaymentMethod(
          managedWalletRef: wallets.selectedWallet!.id,
        ),
        fx: fxIntent,
        settlementMode: payment.payerCoversFee ? SettlementMode.fixReceived : SettlementMode.fixSource,
        settlementCurrency: _resolveSettlementCurrency(amount: amount, fx: fxIntent),
        customer: customer,
      ));
    }
  }

  PaymentQuote? get quotation => _quotation.data;

  bool get isReady => _isLoaded && !_quotation.isLoading && _quotation.error == null;

  Asset? get fee => quotation == null ? null : createAsset(quotation!.expectedFeeTotal!.currency, quotation!.expectedFeeTotal!.amount);
  Asset? get total => quotation == null ? null : createAsset(quotation!.debitAmount!.currency, quotation!.debitAmount!.amount);
  Asset? get recipientGets => quotation == null ? null : createAsset(quotation!.expectedSettlementAmount!.currency, quotation!.expectedSettlementAmount!.amount);

  String _resolveSettlementCurrency({
    required Money amount,
    required FxIntent? fx,
  }) {
    final pair = fx?.pair;
    if (pair != null) {
      switch (fx?.side ?? FxSide.unspecified) {
        case FxSide.buyBaseSellQuote:
          if (pair.base.isNotEmpty) return pair.base;
          break;
        case FxSide.sellBaseBuyQuote:
          if (pair.quote.isNotEmpty) return pair.quote;
          break;
        case FxSide.unspecified:
          break;
      }
      if (amount.currency == pair.base && pair.quote.isNotEmpty) return pair.quote;
      if (amount.currency == pair.quote && pair.base.isNotEmpty) return pair.base;
      if (pair.quote.isNotEmpty) return pair.quote;
      if (pair.base.isNotEmpty) return pair.base;
    }
    return amount.currency;
  }

  Customer _buildCustomer({
    required Recipient? recipient,
    required PaymentMethod method,
  }) {
    final name = _resolveCustomerName(method, recipient);
    String? firstName;
    String? middleName;
    String? lastName;

    if (name != null && name.isNotEmpty) {
      final parts = name.split(RegExp(r'\s+'));
      if (parts.length == 1) {
        firstName = parts.first;
      } else if (parts.length == 2) {
        firstName = parts.first;
        lastName = parts.last;
      } else {
        firstName = parts.first;
        lastName = parts.last;
        middleName = parts.sublist(1, parts.length - 1).join(' ');
      }
    }

    return Customer(
      id: recipient?.id ?? method.recipientRef,
      firstName: firstName,
      middleName: middleName,
      lastName: lastName,
      country: method.cardData?.country,
    );
  }

  String? _resolveCustomerName(PaymentMethod method, Recipient? recipient) {
    final card = method.cardData;
    if (card != null) {
      return '${card.firstName} ${card.lastName}'.trim();
    }

    final iban = method.ibanData;
    if (iban != null && iban.accountHolder.trim().isNotEmpty) {
      return iban.accountHolder.trim();
    }

    final bank = method.bankAccountData;
    if (bank != null && bank.recipientName.trim().isNotEmpty) {
      return bank.recipientName.trim();
    }

    final recipientName = recipient?.name.trim();
    return recipientName?.isNotEmpty == true ? recipientName : null;
  }

  void _setResource(Resource<PaymentQuote> quotation) {
    _quotation = quotation;
    notifyListeners();
  }

  Future<PaymentQuote?> getQuotation(PaymentIntent intent) async {
    if (!_organizations.isOrganizationSet) throw StateError('Organization is not set');
    try {
      _quotation = _quotation.copyWith(isLoading: true, error: null);
      final response = await QuotationService.getQuotation(
        _organizations.current.id, 
        QuotePaymentRequest(
          idempotencyKey: Uuid().v4(),
          intent: intent.toDTO(),
        ),
      );
      _isLoaded = true;
      _setResource(_quotation.copyWith(data: response, isLoading: false, error: null));
    } catch (e) {
      _setResource(_quotation.copyWith(
        data: null,
        error: e is Exception ? e : Exception(e.toString()),
        isLoading: false,
      ));
    }
    notifyListeners();
    return _quotation.data;
  }

  void reset() {
    _setResource(Resource(data: null, isLoading: false, error: null));
    _isLoaded = false;
    notifyListeners();
  }
}