import 'package:flutter/foundation.dart';

import 'package:pshared/models/payment/methods/data.dart';
import 'package:pshared/models/payment/type.dart';
import 'package:pshared/models/recipient/recipient.dart';
import 'package:pshared/provider/recipient/pmethods.dart';


class PaymentFlowProvider extends ChangeNotifier {
  PaymentType _selectedType;
  PaymentMethodData? _manualPaymentData;
  MethodMap _availableTypes = {};
  Recipient? _recipient;

  PaymentFlowProvider({
    required PaymentType initialType,
  }) : _selectedType = initialType;

  PaymentType get selectedType => _selectedType;
  PaymentMethodData? get manualPaymentData => _manualPaymentData;
  Recipient? get recipient => _recipient;

  bool get hasRecipient => _recipient != null;

  MethodMap get availableTypes => hasRecipient
      ? _availableTypes
      : {for (final type in PaymentType.values) type: null};

  PaymentMethodData? get selectedPaymentData =>
      hasRecipient ? _availableTypes[_selectedType] : _manualPaymentData;

  void syncWith({
    required Recipient? recipient,
    required PaymentMethodsProvider methodsProvider,
    PaymentType? preferredType,
  }) =>
      _applyState(
        recipient: recipient,
        availableTypes: methodsProvider.availableTypesForRecipient(recipient),
        preferredType: preferredType,
        forceResetManualData: false,
      );

  void reset({
    required Recipient? recipient,
    required PaymentMethodsProvider methodsProvider,
    PaymentType? preferredType,
  }) =>
      _applyState(
        recipient: recipient,
        availableTypes: methodsProvider.availableTypesForRecipient(recipient),
        preferredType: preferredType,
        forceResetManualData: true,
      );

  void selectType(PaymentType type, {bool resetManualData = false}) {
    if (_selectedType == type && (!resetManualData || _manualPaymentData == null)) {
      return;
    }

    _selectedType = type;
    if (resetManualData) {
      _manualPaymentData = null;
    }
    notifyListeners();
  }

  void setManualPaymentData(PaymentMethodData? data) {
    _manualPaymentData = data;
    notifyListeners();
  }

  PaymentType _resolveSelectedType({
    required Recipient? recipient,
    required MethodMap availableTypes,
    PaymentType? preferredType,
  }) {
    if (recipient == null) {
      return preferredType ?? _selectedType;
    }

    if (availableTypes.isEmpty) {
      return preferredType ?? PaymentType.bankAccount;
    }

    if (availableTypes.keys.contains(_selectedType)) {
      return _selectedType;
    }

    if (preferredType != null && availableTypes.keys.contains(preferredType)) {
      return preferredType;
    }

    return availableTypes.keys.first;
  }

  void _applyState({
    required Recipient? recipient,
    required MethodMap availableTypes,
    required PaymentType? preferredType,
    required bool forceResetManualData,
  }) {
    final resolvedType = _resolveSelectedType(
      recipient: recipient,
      availableTypes: availableTypes,
      preferredType: preferredType,
    );

    var hasChanges = false;

    if (_recipient != recipient) {
      _recipient = recipient;
      hasChanges = true;
    }

    if (!mapEquals(_availableTypes, availableTypes)) {
      _availableTypes = availableTypes;
      hasChanges = true;
    }

    if (resolvedType != _selectedType) {
      _selectedType = resolvedType;
      hasChanges = true;
    }

    if ((recipient != null || forceResetManualData) && _manualPaymentData != null) {
      _manualPaymentData = null;
      hasChanges = true;
    }

    if (hasChanges) notifyListeners();
  }
}