import 'package:flutter/material.dart';
import 'package:kmobile/api/services/auth_service.dart';
import 'package:kmobile/di/injection.dart';
import 'package:kmobile/features/fund_transfer/screens/tpin_prompt_screen.dart';

import '../../../l10n/app_localizations.dart';

class TransactionPinScreen extends StatefulWidget {
  final Future<void> Function(BuildContext, String) onPinCompleted;

  const TransactionPinScreen({super.key, required this.onPinCompleted});

  @override
  State<TransactionPinScreen> createState() => _TransactionPinScreenState();
}

class _TransactionPinScreenState extends State<TransactionPinScreen> {
  final List<String> _pin = [];
  bool _loading = true;
  bool _isSubmitting = false;

  @override
  void initState() {
    super.initState();
    _checkIfTpinIsSet();
  }

  Future<void> _checkIfTpinIsSet() async {
    setState(() => _loading = true);
    try {
      final authService = getIt<AuthService>();
      final isSet = await authService.checkTpin();
      if (!isSet && mounted) {
        Navigator.pushReplacement(
          context,
          MaterialPageRoute(builder: (_) => const TpinSetupPromptScreen()),
        );
      } else if (mounted) {
        setState(() => _loading = false);
      }
    } catch (e) {
      if (mounted) {
        setState(() => _loading = false);
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(AppLocalizations.of(context).tpinStatusFailed),
          ),
        );
      }
    }
  }

  void _onKeyPressed(String value) {
    if (_isSubmitting) return;
    setState(() {
      if (value == 'back') {
        if (_pin.isNotEmpty) _pin.removeLast();
      } else if (_pin.length < 6) {
        _pin.add(value);
      }
    });
  }

  Future<void> _submitPin() async {
    if (_isSubmitting) return;

    if (_pin.length == 6) {
      setState(() => _isSubmitting = true);
      try {
        await widget.onPinCompleted(context, _pin.join());
      } finally {
        if (mounted) {
          setState(() => _isSubmitting = false);
        }
      }
    } else {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(AppLocalizations.of(context).enter6DigitTpin),
        ),
      );
    }
  }

  Widget _buildPinIndicators() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: List.generate(6, (index) {
        return Container(
          margin: const EdgeInsets.symmetric(horizontal: 8),
          width: 20,
          height: 20,
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            border: Border.all(color: Theme.of(context).primaryColor, width: 2),
            color: index < _pin.length
                ? Theme.of(context).colorScheme.primary
                : Colors.transparent,
          ),
        );
      }),
    );
  }

  Widget _buildKey(String label, {IconData? icon}) {
    return Expanded(
      child: InkWell(
        onTap: () => label == 'done' ? _submitPin() : _onKeyPressed(label),
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: 20),
          child: Center(
            child: _isSubmitting && label == 'done'
                ? const CircularProgressIndicator()
                : icon != null
                    ? Icon(icon, size: 28)
                    : Text(label, style: const TextStyle(fontSize: 24)),
          ),
        ),
      ),
    );
  }

  Widget _buildKeypad() {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Row(children: [_buildKey('1'), _buildKey('2'), _buildKey('3')]),
        Row(children: [_buildKey('4'), _buildKey('5'), _buildKey('6')]),
        Row(children: [_buildKey('7'), _buildKey('8'), _buildKey('9')]),
        Row(
          children: [
            _buildKey('done', icon: Icons.check),
            _buildKey('0'),
            _buildKey('back', icon: Icons.backspace_outlined),
          ],
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(AppLocalizations.of(context).tpin),
        centerTitle: false,
      ),
      body: _loading
          ? const Center(child: CircularProgressIndicator())
          : Padding(
              padding: const EdgeInsets.only(bottom: 20.0),
              child: Column(
                children: [
                  const Spacer(),
                  Text(
                    AppLocalizations.of(context).enterTpin,
                    style: const TextStyle(fontSize: 18),
                  ),
                  const SizedBox(height: 20),
                  _buildPinIndicators(),
                  const Spacer(),
                  _buildKeypad(),
                ],
              ),
            ),
    );
  }
}