import 'dart:async';
import 'package:flutter/material.dart';
import '../theme.dart';
import '../route_transitions.dart';
import '../feedback_helper.dart';
import 'business_setup_screen.dart';

class OtpVerificationScreen extends StatefulWidget {
  final String mobileNumber;

  const OtpVerificationScreen({super.key, required this.mobileNumber});

  @override
  State<OtpVerificationScreen> createState() => _OtpVerificationScreenState();
}

class _OtpVerificationScreenState extends State<OtpVerificationScreen> {
  late Timer _timer;
  int _timeLeft = 45;
  final List<TextEditingController> _controllers = List.generate(6, (_) => TextEditingController());
  final List<FocusNode> _focusNodes = List.generate(6, (_) => FocusNode());

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

  void _startCountdown() {
    _timeLeft = 45;
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (_timeLeft <= 0) {
        _timer.cancel();
      } else {
        setState(() {
          _timeLeft--;
        });
      }
    });
  }

  @override
  void dispose() {
    _timer.cancel();
    for (var controller in _controllers) {
      controller.dispose();
    }
    for (var node in _focusNodes) {
      node.dispose();
    }
    super.dispose();
  }

  void _verifyOtp() {
    final code = _controllers.map((c) => c.text.trim()).join();
    if (code.length < 6) {
      AppFeedback.error();
      showTopAlert(context, 'Please enter a valid 6-digit OTP code.', isError: true);
      return;
    }
    AppFeedback.success();
    showTopAlert(context, 'OTP Verified Successfully!');
    Navigator.pushReplacement(
      context,
      FadeSlidePageRoute(child: const BusinessSetupScreen()),
    );
  }

  String _getFormattedTime() {
    return '00:${_timeLeft.toString().padLeft(2, '0')}';
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final padding = context.responsivePadding;

    final displayMobile = widget.mobileNumber.length == 10
        ? '+91 ${widget.mobileNumber.substring(0, 5)} ${widget.mobileNumber.substring(5)}'
        : '+91 ${widget.mobileNumber}';

    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: const Icon(Icons.arrow_back, color: Color(0xFFBA1A20)),
          onPressed: () {
            AppFeedback.click();
            Navigator.pop(context);
          },
        ),
        title: Text(
          'PozoApp',
          style: theme.textTheme.headlineMedium?.copyWith(
            color: theme.colorScheme.primary,
            fontWeight: FontWeight.bold,
          ),
        ),
        actions: [
          Padding(
            padding: EdgeInsets.symmetric(horizontal: padding),
            child: Center(
              child: Text(
                'Step 2.5 of 5',
                style: theme.textTheme.labelMedium?.copyWith(
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),
          )
        ],
        bottom: PreferredSize(
          preferredSize: const Size.fromHeight(6),
          child: Row(
            children: List.generate(5, (index) {
              return Expanded(
                child: Container(
                  height: 6,
                  margin: const EdgeInsets.symmetric(horizontal: 2.0),
                  decoration: BoxDecoration(
                    color: index <= 1
                        ? theme.colorScheme.primary
                        : (index == 2 ? theme.colorScheme.primary.withOpacity(0.5) : theme.colorScheme.surfaceContainerHighest),
                    borderRadius: BorderRadius.circular(3),
                  ),
                ),
              );
            }),
          ),
        ),
      ),
      body: SafeArea(
        child: Column(
          children: [
            Expanded(
              child: Center(
                child: ConstrainedBox(
                  constraints: const BoxConstraints(maxWidth: 600),
                  child: SingleChildScrollView(
                    physics: const BouncingScrollPhysics(),
                    child: Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 16.0),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.center,
                        children: [
                          // Alert envelope pulse symbol with SlideFadeEntrance
                          SlideFadeEntrance(
                            delay: Duration.zero,
                            child: Center(
                              child: Container(
                                width: 96,
                                height: 96,
                                decoration: BoxDecoration(
                                  color: theme.colorScheme.surfaceContainerHigh,
                                  shape: BoxShape.circle,
                                ),
                                child: Center(
                                  child: Container(
                                    width: 72,
                                    height: 72,
                                    decoration: BoxDecoration(
                                      color: Colors.white,
                                      borderRadius: BorderRadius.circular(16),
                                      boxShadow: [
                                        BoxShadow(
                                          color: Colors.black.withOpacity(0.06),
                                          blurRadius: 10,
                                        )
                                      ],
                                    ),
                                    child: Icon(
                                      Icons.sms,
                                      color: theme.colorScheme.primary,
                                      size: 38,
                                    ),
                                  ),
                                ),
                              ),
                            ),
                          ),
                          const SizedBox(height: 16),
                          SlideFadeEntrance(
                            delay: const Duration(milliseconds: 100),
                            child: Text(
                              'Verifying your number',
                              textAlign: TextAlign.center,
                              style: theme.textTheme.headlineMedium?.copyWith(
                                fontWeight: FontWeight.bold,
                              ),
                            ),
                          ),
                          const SizedBox(height: 16),
                          SlideFadeEntrance(
                            delay: const Duration(milliseconds: 150),
                            child: Row(
                              mainAxisAlignment: MainAxisAlignment.center,
                              crossAxisAlignment: CrossAxisAlignment.center,
                              children: [
                                Text(
                                  "Sent code to $displayMobile",
                                  style: theme.textTheme.bodyMedium,
                                ),
                                const SizedBox(width: 8),
                                InteractiveScale(
                                  onTap: () {
                                    AppFeedback.click();
                                    Navigator.pop(context);
                                  },
                                  child: Text(
                                    'Edit',
                                    style: TextStyle(
                                      color: theme.colorScheme.primary,
                                      fontWeight: FontWeight.bold,
                                      fontSize: 14,
                                    ),
                                  ),
                                ),
                              ],
                            ),
                          ),

                          const SizedBox(height: 20),
                          
                          // 6 Custom Inputs Fields with SlideFadeEntrance
                          SlideFadeEntrance(
                            delay: const Duration(milliseconds: 200),
                            child: Row(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: List.generate(11, (index) {
                                if (index.isOdd) {
                                  return const SizedBox(width: 8);
                                }
                                final fieldIndex = index ~/ 2;
                                return SizedBox(
                                  width: 44,
                                  child: TextField(
                                    controller: _controllers[fieldIndex],
                                    focusNode: _focusNodes[fieldIndex],
                                    keyboardType: TextInputType.number,
                                    textAlign: TextAlign.center,
                                    maxLength: 1,
                                    style: const TextStyle(
                                      fontSize: 20,
                                      fontWeight: FontWeight.bold,
                                    ),
                                    decoration: InputDecoration(
                                      counterText: '',
                                      contentPadding: const EdgeInsets.symmetric(vertical: 12),
                                      enabledBorder: OutlineInputBorder(
                                        borderRadius: BorderRadius.circular(12),
                                        borderSide: BorderSide(color: theme.colorScheme.outlineVariant),
                                      ),
                                      focusedBorder: OutlineInputBorder(
                                        borderRadius: BorderRadius.circular(12),
                                        borderSide: BorderSide(color: theme.colorScheme.primary, width: 2),
                                      ),
                                    ),
                                    onChanged: (value) {
                                      AppFeedback.subtleHaptic();
                                      if (value.isNotEmpty) {
                                        if (fieldIndex < 5) {
                                          _focusNodes[fieldIndex + 1].requestFocus();
                                        } else {
                                          _verifyOtp();
                                        }
                                      } else if (value.isEmpty && fieldIndex > 0) {
                                        _focusNodes[fieldIndex - 1].requestFocus();
                                      }
                                    },
                                  ),
                                );
                              }),
                            ),
                          ),

                          const SizedBox(height: 24),
                          
                          // Auto detect loader card with SlideFadeEntrance
                          SlideFadeEntrance(
                            delay: const Duration(milliseconds: 250),
                            child: Container(
                              padding: const EdgeInsets.symmetric(vertical: 12, horizontal: 16),
                              decoration: BoxDecoration(
                                color: theme.colorScheme.surfaceContainerLow,
                                borderRadius: BorderRadius.circular(16),
                              ),
                              child: Row(
                                mainAxisAlignment: MainAxisAlignment.center,
                                children: [
                                  SizedBox(
                                    width: 14,
                                    height: 14,
                                    child: CircularProgressIndicator(
                                      strokeWidth: 2,
                                      valueColor: AlwaysStoppedAnimation(theme.colorScheme.primary),
                                    ),
                                  ),
                                  const SizedBox(width: 12),
                                  Text(
                                    'Auto-detecting OTP...',
                                    style: theme.textTheme.bodySmall?.copyWith(
                                      fontWeight: FontWeight.bold,
                                    ),
                                  ),
                                ],
                              ),
                            ),
                          ),

                          const SizedBox(height: 24),
                          
                          // Resending timer action row
                          SlideFadeEntrance(
                            delay: const Duration(milliseconds: 300),
                            child: Row(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: [
                                const Icon(Icons.schedule, size: 16, color: Colors.grey),
                                const SizedBox(width: 6),
                                Text(
                                  _timeLeft > 0
                                      ? 'Resend code in ${_getFormattedTime()}'
                                      : 'Resend Code via SMS',
                                  style: theme.textTheme.bodyMedium,
                                ),
                              ],
                            ),
                          ),
                          const SizedBox(height: 16),
                          
                          // WhatsApp custom CTA button with InteractiveScale
                          SlideFadeEntrance(
                            delay: const Duration(milliseconds: 350),
                            child: InteractiveScale(
                              child: OutlinedButton.icon(
                                onPressed: () {
                                  AppFeedback.click();
                                  showTopAlert(
                                    context,
                                    'WhatsApp verification request sent!',
                                    icon: Icons.chat_bubble_outline,
                                  );
                                },
                                icon: const Icon(Icons.forum, color: Colors.green, size: 18),
                                label: const Text(
                                  'Resend via WhatsApp',
                                  style: TextStyle(
                                    fontSize: 13,
                                    fontWeight: FontWeight.bold,
                                    color: Colors.black87,
                                  ),
                                ),
                                style: OutlinedButton.styleFrom(
                                  backgroundColor: Colors.white,
                                  side: const BorderSide(color: Color(0xFFE2E2E2)),
                                  elevation: 1,
                                  minimumSize: const Size(220, 48),
                                  shape: RoundedRectangleBorder(
                                    borderRadius: BorderRadius.circular(12),
                                  ),
                                ),
                              ),
                            ),
                          )
                        ],
                      ),
                    ),
                  ),
                ),
              ),
            ),

            // Pinned Bottom Dock
            Container(
              height: 80,
              decoration: BoxDecoration(
                color: Colors.white,
                border: Border(top: BorderSide(color: Colors.grey[200]!)),
              ),
              child: Center(
                child: ConstrainedBox(
                  constraints: const BoxConstraints(maxWidth: 600),
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 16.0),
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                      children: [
                        _buildFooterAction(Icons.help_outline, 'Help', () {
                          showTopAlert(
                            context,
                            'Support agent contacted. We will call you shortly.',
                            icon: Icons.support_agent_outlined,
                          );
                        }),
                        _buildFooterAction(Icons.save, 'Save Draft', () {
                          showTopAlert(
                            context,
                            'Onboarding draft saved successfully!',
                            icon: Icons.save_outlined,
                          );
                        }),
                        InteractiveScale(
                          child: TextButton.icon(
                            onPressed: _verifyOtp,
                            icon: const Text(
                              'Verify Manually',
                              style: TextStyle(fontWeight: FontWeight.bold),
                            ),
                            label: const Icon(Icons.arrow_forward, size: 16),
                            style: TextButton.styleFrom(
                              foregroundColor: Colors.white,
                              backgroundColor: theme.colorScheme.primary,
                              padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 12),
                              shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(16),
                              ),
                            ),
                          ),
                        )
                      ],
                    ),
                  ),
                ),
              ),
            )
          ],
        ),
      ),
    );
  }

  Widget _buildFooterAction(IconData icon, String label, VoidCallback onTap) {
    return InteractiveScale(
      onTap: () {
        AppFeedback.click();
        onTap();
      },
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(icon, color: Colors.grey[600], size: 22),
          const SizedBox(height: 4),
          Text(
            label,
            style: TextStyle(
              fontSize: 10,
              fontWeight: FontWeight.bold,
              color: Colors.grey[600],
            ),
          )
        ],
      ),
    );
  }
}