import 'dart:developer';

import 'package:flutter/material.dart';
import 'package:kmobile/app.dart';
import 'package:kmobile/di/injection.dart';
import 'package:kmobile/security/secure_storage.dart';
import 'package:local_auth/local_auth.dart';

enum MPinMode { enter, set, confirm }

class MPinScreen extends StatefulWidget {
  final MPinMode mode;
  final String? initialPin;
  final void Function(String pin)? onCompleted;

  const MPinScreen({
    super.key,
    required this.mode,
    this.initialPin,
    this.onCompleted,
  });

  @override
  State<MPinScreen> createState() => _MPinScreenState();
}

class _MPinScreenState extends State<MPinScreen> {
  List<String> mPin = [];
  String? errorText;

  @override
  void initState() {
    super.initState();
    if (widget.mode == MPinMode.enter) {
      _tryBiometricBeforePin();
    }
  }

  Future<void> _tryBiometricBeforePin() async {
    final storage = getIt<SecureStorage>();
    final enabled = await storage.read('biometric_enabled');
    log('biometric_enabled: $enabled');
    if (enabled != null && enabled) {
      final auth = LocalAuthentication();
      if (await auth.canCheckBiometrics) {
        final didAuth = await auth.authenticate(
          localizedReason: 'Authenticate to access kMobile',
          options: const AuthenticationOptions(biometricOnly: true),
        );
        if (didAuth && mounted) {
          // success → directly “complete” your flow
          widget.onCompleted?.call('');
          // or navigate yourself:
          // Navigator.of(context).pushReplacement(
          //   MaterialPageRoute(builder: (_) => const NavigationScaffold()));
        }
      }
    }
  }

  void addDigit(String digit) {
    if (mPin.length < 4) {
      setState(() {
        mPin.add(digit);
        errorText = null;
      });
      if (mPin.length == 4) {
        _handleComplete();
      }
    }
  }

  void deleteDigit() {
    if (mPin.isNotEmpty) {
      setState(() {
        mPin.removeLast();
        errorText = null;
      });
    }
  }

  Future<void> _handleComplete() async {
    final pin = mPin.join();
    final storage = SecureStorage();

    switch (widget.mode) {
      case MPinMode.enter:
        final storedPin = await storage.read('mpin');
        log('storedPin: $storedPin');
        if (storedPin == int.tryParse(pin)) {
          widget.onCompleted?.call(pin);
        } else {
          setState(() {
            errorText = "Incorrect mPIN. Try again.";
            mPin.clear();
          });
        }
        break;
      case MPinMode.set:
        // propagate parent onCompleted into confirm step
        Navigator.push(
          context,
          MaterialPageRoute(
            builder: (_) => MPinScreen(
              mode: MPinMode.confirm,
              initialPin: pin,
              onCompleted: widget.onCompleted, // <-- use parent callback
            ),
          ),
        );
        break;
      case MPinMode.confirm:
        if (widget.initialPin == pin) {
          // 1) persist the pin
          await storage.write('mpin', pin);

          // 3) now clear the entire navigation stack and go to your main scaffold
          if (mounted) {
            Navigator.of(context, rootNavigator: true).pushAndRemoveUntil(
              MaterialPageRoute(builder: (_) => const NavigationScaffold()),
              (route) => false,
            );
          }
        } else {
          setState(() {
            errorText = "Pins do not match. Try again.";
            mPin.clear();
          });
        }
        break;
    }
  }

  Widget buildMPinDots() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: List.generate(4, (index) {
        return Container(
          margin: const EdgeInsets.all(8),
          width: 15,
          height: 15,
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            color: index < mPin.length ? Colors.black : Colors.grey[400],
          ),
        );
      }),
    );
  }

  Widget buildNumberPad() {
    List<List<String>> keys = [
      ['1', '2', '3'],
      ['4', '5', '6'],
      ['7', '8', '9'],
      ['Enter', '0', '<']
    ];

    return Column(
      children: keys.map((row) {
        return Row(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: row.map((key) {
            return Padding(
              padding: const EdgeInsets.all(8.0),
              child: GestureDetector(
                onTap: () {
                  if (key == '<') {
                    deleteDigit();
                  } else if (key == 'Enter') {
                    if (mPin.length == 4) {
                      _handleComplete();
                    } else {
                      setState(() {
                        errorText = "Please enter 4 digits";
                      });
                    }
                  } else if (key.isNotEmpty) {
                    addDigit(key);
                  }
                },
                child: Container(
                  width: 70,
                  height: 70,
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: Colors.grey[200],
                  ),
                  alignment: Alignment.center,
                  child: key == 'Enter'
                      ? const Icon(Icons.check)
                      : Text(
                          key == '<' ? '⌫' : key,
                          style: TextStyle(
                            fontSize: 20,
                            color: key == 'Enter' ? Colors.blue : Colors.black,
                          ),
                        ),
                ),
              ),
            );
          }).toList(),
        );
      }).toList(),
    );
  }

  String getTitle() {
    switch (widget.mode) {
      case MPinMode.enter:
        return "Enter your mPIN";
      case MPinMode.set:
        return "Set your new mPIN";
      case MPinMode.confirm:
        return "Confirm your mPIN";
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: [
            const Spacer(),
            // Logo
            Image.asset('assets/images/logo.png', height: 100),
            const SizedBox(height: 20),
            Text(
              getTitle(),
              style: const TextStyle(fontSize: 20, fontWeight: FontWeight.w500),
            ),
            const SizedBox(height: 20),
            buildMPinDots(),
            if (errorText != null)
              Padding(
                padding: const EdgeInsets.only(top: 8.0),
                child:
                    Text(errorText!, style: const TextStyle(color: Colors.red)),
              ),
            const Spacer(),
            buildNumberPad(),
            const Spacer(),
          ],
        ),
      ),
    );
  }
}