import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

import '../../../data/models/app_cubit.dart';
import '../../../data/models/payment_cubit.dart';
import '../../../data/models/payment_state.dart';
import '../../../data/models/transaction_cubit.dart';
import '../../../g1/currency.dart';
import '../../logger.dart';
import '../../pay_helper.dart';
import '../../tutorial_keys.dart';
import '../../ui_helpers.dart';
import 'g1_textfield.dart';

class PayForm extends StatefulWidget {
  const PayForm({super.key});

  @override
  State<PayForm> createState() => _PayFormState();
}

class _PayFormState extends State<PayForm> {
  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
  final GlobalKey<FormFieldState<String>> _formCommentKey =
      GlobalKey<FormFieldState<String>>();
  final TextEditingController _commentController = TextEditingController();
  final ValueNotifier<String> _feedbackNotifier = ValueNotifier<String>('');

  @override
  void dispose() {
    _commentController.dispose();
    _feedbackNotifier.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<PaymentCubit, PaymentState>(
        builder: (BuildContext context, PaymentState state) {
      final AppCubit appCubit = context.watch<AppCubit>();
      final double currentUd = appCubit.currentUd;
      final Currency currency = appCubit.currency;
      if (state.comment != null && _commentController.text != state.comment) {
        _commentController.text = state.comment;
      }
      if (state.amount == null || state.amount == 0) {
        _feedbackNotifier.value = '';
      }

      final bool sentDisabled =
          _onPressed(state, context, currency, currentUd) == null;
      final Color sentColor =
          sentDisabled ? Colors.grey : Theme.of(context).primaryColor;
      return Form(
        key: _formKey,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            const SizedBox(height: 10.0),
            G1PayAmountField(key: payAmountKey),
            const SizedBox(height: 10.0),
            Row(children: <Widget>[
              Expanded(
                  child: TextFormField(
                key: _formCommentKey,
                inputFormatters: <TextInputFormatter>[
                  NoNewLineTextInputFormatter()
                ],
                controller: _commentController,
                onChanged: (String? value) {
                  context.read<PaymentCubit>().setComment(value ?? '');
                },
                decoration: InputDecoration(
                  labelText: tr('g1_form_pay_desc'),
                  hintText: tr('g1_form_pay_hint'),
                  border: const OutlineInputBorder(),
                ),
                validator: (String? value) {
                  if (value != null &&
                      !basicEnglishCharsRegExp.hasMatch(value)) {
                    return tr('valid_comment');
                  }
                  return null;
                },
                // Disallow autocomplete
                autofillHints: const <String>[],
              )),
              const SizedBox(width: 5.0),
              Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  Material(
                    color: Colors.transparent,
                    child: IgnorePointer(
                      ignoring: sentDisabled,
                      child: IconTheme(
                        data: const IconThemeData(size: 40.0),
                        child: IconButton(
                          key: paySentKey,
                          tooltip: tr('g1_form_pay_send'),
                          icon: Icon(
                            Icons.send,
                            color: sentColor,
                          ),
                          onPressed:
                              _onPressed(state, context, currency, currentUd),
                          splashRadius: 20,
                          splashColor: Colors.white.withOpacity(0.5),
                          highlightColor: Colors.transparent,
                        ),
                      ),
                    ),
                  ),
                  Text(
                    tr('g1_form_pay_send'),
                    style: TextStyle(fontSize: 12, color: sentColor),
                  ),
                ],
              ),
            ]),
            const SizedBox(height: 10.0),
            ValueListenableBuilder<String>(
              valueListenable: _feedbackNotifier,
              builder: (BuildContext context, String value, Widget? child) {
                if (value.isNotEmpty) {
                  return Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      const Icon(Icons.error_outline, color: Colors.red),
                      const SizedBox(width: 4),
                      Text(
                        capitalize(value),
                        style: const TextStyle(color: Colors.red),
                      ),
                    ],
                  );
                } else {
                  return const SizedBox.shrink();
                }
              },
            ),
          ],
        ),
      );
    });
  }

  Future<void> Function()? _onPressed(PaymentState state, BuildContext context,
      Currency currency, double currentUd) {
    final bool isG1 = currency == Currency.G1;
    return (!state.canBeSent() ||
            state.amount == null ||
            !_commentValidate() ||
            !_weHaveBalance(context, state.amount!, currency, currentUd))
        ? null
        : () async {
            try {
              await payWithRetry(
                  context: context,
                  to: state.contact!,
                  amount: state.amount!,
                  isG1: isG1,
                  currentUd: currentUd,
                  comment: state.comment);
            } on RetryException {
              // Here the transactions can be lost, so we must implement some manual retry use

              await payWithRetry(
                  context: context,
                  to: state.contact!,
                  amount: state.amount!,
                  isG1: isG1,
                  currentUd: currentUd,
                  comment: state.comment,
                  useMempool: true);
            }
          };
  }

  bool _commentValidate() {
    final String currentComment = _commentController.value.text;
    final bool val = (currentComment != null &&
            basicEnglishCharsRegExp.hasMatch(currentComment)) ||
        currentComment.isEmpty;
    logger('Validating comment: $val');
    if (_formKey.currentState != null) {
      _formKey.currentState!.validate();
    }
    return val;
  }

  bool _weHaveBalance(BuildContext context, double amount, Currency currency,
      double currentUd) {
    final double balance =
        convertAmount(currency == Currency.G1, getBalance(context), currentUd);
    logger('We have $balance G1, need $amount');
    final bool weHave = balance >= amount;

    if (!weHave) {
      _feedbackNotifier.value = tr('insufficient balance');
    } else {
      _feedbackNotifier.value = '';
    }
    return weHave;
  }

  double getBalance(BuildContext context) =>
      context.watch<TransactionCubit>().balance;
}

class RetryException implements Exception {
  RetryException();
}

class NoNewLineTextInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(
      TextEditingValue oldValue, TextEditingValue newValue) {
    final int cursorPosition = newValue.selection.baseOffset;
    final String newText = newValue.text.replaceAll('\n', '');
    final TextSelection newSelection =
        TextSelection.collapsed(offset: cursorPosition);
    return TextEditingValue(
      text: newText,
      selection: newSelection,
    );
  }
}