import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:shared_preferences/shared_preferences.dart';

import '../models/server_config.dart';
import '../providers/providers.dart';
import '../services/mqtt_service.dart' show ConnectionStatus;
import '../services/purchase_service.dart';
import '../services/wol_service.dart';
import '../theme/app_theme.dart';
import '../widgets/status_dot.dart';
import 'trace_screen.dart';

class SettingsScreen extends ConsumerStatefulWidget {
  const SettingsScreen({super.key});

  @override
  ConsumerState<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends ConsumerState<SettingsScreen> {
  final _formKey = GlobalKey<FormState>();
  late final TextEditingController _localHostController;
  late final TextEditingController _vpnHostController;
  late final TextEditingController _remoteHostController;
  late final TextEditingController _portController;
  late final TextEditingController _macController;
  late final TextEditingController _mqttTokenController;
  bool _isWaking = false;
  bool _iapLoading = false;

  @override
  void initState() {
    super.initState();
    PurchaseService.instance.addListener(_onPurchaseChanged);
    final config = ref.read(serverConfigProvider);
    _localHostController =
        TextEditingController(text: config?.localHost ?? '');
    _vpnHostController =
        TextEditingController(text: config?.vpnHost ?? '');
    _remoteHostController =
        TextEditingController(text: config?.host ?? '');
    _portController =
        TextEditingController(text: '${config?.port ?? 8765}');
    _macController =
        TextEditingController(text: config?.macAddress ?? '');
    _mqttTokenController =
        TextEditingController(text: config?.mqttToken ?? '');
  }

  @override
  void dispose() {
    PurchaseService.instance.removeListener(_onPurchaseChanged);
    _localHostController.dispose();
    _vpnHostController.dispose();
    _remoteHostController.dispose();
    _portController.dispose();
    _macController.dispose();
    _mqttTokenController.dispose();
    super.dispose();
  }

  void _onPurchaseChanged() {
    if (!mounted) return;
    final isPro = PurchaseService.instance.isPro;
    ref.read(isProProvider.notifier).state = isPro;
    setState(() => _iapLoading = PurchaseService.instance.isLoading);
    final error = PurchaseService.instance.errorMessage;
    if (error != null && mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(error)),
      );
    }
    if (isPro && mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('PAILot Pro activated. Enjoy unlimited sessions!'),
          duration: Duration(seconds: 3),
        ),
      );
    }
  }

  Future<void> _handleUpgrade() async {
    setState(() => _iapLoading = true);
    await PurchaseService.instance.purchaseFullAccess();
  }

  Future<void> _handleRestore() async {
    setState(() => _iapLoading = true);
    await PurchaseService.instance.restorePurchases();
    if (mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('Checking for previous purchases...'),
          duration: Duration(seconds: 2),
        ),
      );
    }
  }

  Future<void> _save() async {
    if (!_formKey.currentState!.validate()) return;

    final config = ServerConfig(
      host: _remoteHostController.text.trim(),
      port: int.tryParse(_portController.text.trim()) ?? 8765,
      localHost: _localHostController.text.trim().isEmpty
          ? null
          : _localHostController.text.trim(),
      vpnHost: _vpnHostController.text.trim().isEmpty
          ? null
          : _vpnHostController.text.trim(),
      macAddress: _macController.text.trim().isEmpty
          ? null
          : _macController.text.trim(),
      mqttToken: _mqttTokenController.text.trim().isEmpty
          ? null
          : _mqttTokenController.text.trim(),
    );

    await ref.read(serverConfigProvider.notifier).save(config);

    if (mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('Server configuration saved'),
          duration: Duration(seconds: 2),
        ),
      );
    }
  }

  Future<void> _wakeMac() async {
    final mac = _macController.text.trim();
    if (mac.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('No MAC address configured')),
      );
      return;
    }

    setState(() => _isWaking = true);

    try {
      await WolService.wake(mac, localHost: _localHostController.text.trim());
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Wake-on-LAN packet sent')),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('WoL failed: $e')),
        );
      }
    } finally {
      if (mounted) setState(() => _isWaking = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final wsStatus = ref.watch(wsStatusProvider);
    return Scaffold(
      appBar: AppBar(
        title: const Text('Settings'),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Form(
          key: _formKey,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              // Connection status card
              Card(
                child: Padding(
                  padding: const EdgeInsets.all(16),
                  child: Row(
                    children: [
                      StatusDot(status: wsStatus),
                      const SizedBox(width: 12),
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              _statusText(wsStatus),
                              style: Theme.of(context).textTheme.bodyLarge,
                            ),
                            if (ref.watch(connectedViaProvider).isNotEmpty)
                              Text(
                                'via ${ref.watch(connectedViaProvider)}',
                                style: TextStyle(
                                  fontSize: 12,
                                  color: Colors.grey.shade500,
                                ),
                              ),
                          ],
                        ),
                      ),
                    ],
                  ),
                ),
              ),
              const SizedBox(height: 24),

              // Local address
              Text('Local Address',
                  style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 4),
              TextFormField(
                controller: _localHostController,
                decoration: const InputDecoration(
                  hintText: '192.168.1.100',
                ),
                keyboardType: TextInputType.url,
                validator: (v) {
                  if (v == null || v.trim().isEmpty) return null;
                  final ip = RegExp(r'^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$');
                  return ip.hasMatch(v.trim()) ? null : 'Enter a valid IP address';
                },
              ),
              const SizedBox(height: 16),

              // VPN address
              Text('VPN Address',
                  style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 4),
              TextFormField(
                controller: _vpnHostController,
                decoration: const InputDecoration(
                  hintText: '10.8.0.1 (OpenVPN static IP)',
                ),
                keyboardType: TextInputType.url,
                validator: (v) {
                  if (v == null || v.trim().isEmpty) return null;
                  final ip = RegExp(r'^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$');
                  return ip.hasMatch(v.trim()) ? null : 'Enter a valid IP address';
                },
              ),
              const SizedBox(height: 16),

              // Remote address
              Text('Remote Address',
                  style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 4),
              TextFormField(
                controller: _remoteHostController,
                decoration: const InputDecoration(
                  hintText: 'your-server.example.com',
                ),
                keyboardType: TextInputType.url,
                validator: (v) =>
                    (v == null || v.trim().isEmpty) ? 'Required' : null,
              ),
              const SizedBox(height: 16),

              // Port
              Text('Port', style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 4),
              TextFormField(
                controller: _portController,
                decoration: const InputDecoration(
                  hintText: '8765',
                ),
                keyboardType: TextInputType.number,
                validator: (v) {
                  if (v == null || v.trim().isEmpty) return 'Required';
                  final port = int.tryParse(v.trim());
                  if (port == null || port < 1 || port > 65535) {
                    return 'Port must be 1–65535';
                  }
                  return null;
                },
              ),
              const SizedBox(height: 16),

              // MAC address
              Text('MAC Address (for Wake-on-LAN)',
                  style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 4),
              TextFormField(
                controller: _macController,
                decoration: const InputDecoration(
                  hintText: 'AA:BB:CC:DD:EE:FF',
                ),
                validator: (v) {
                  if (v == null || v.trim().isEmpty) return null;
                  final mac = RegExp(
                      r'^[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}$');
                  return mac.hasMatch(v.trim())
                      ? null
                      : 'Enter a valid MAC address (AA:BB:CC:DD:EE:FF)';
                },
              ),
              const SizedBox(height: 16),

              // MQTT Token
              Text('MQTT Token',
                  style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 4),
              TextFormField(
                controller: _mqttTokenController,
                decoration: const InputDecoration(
                  hintText: 'Shared secret for MQTT auth',
                ),
                obscureText: true,
              ),
              const SizedBox(height: 24),

              // Save button
              ElevatedButton(
                onPressed: _save,
                style: ElevatedButton.styleFrom(
                  backgroundColor: AppColors.accent,
                  foregroundColor: Colors.white,
                ),
                child: const Text('Save Configuration'),
              ),
              const SizedBox(height: 12),

              // Wake Mac button
              OutlinedButton.icon(
                onPressed: _isWaking ? null : _wakeMac,
                icon: _isWaking
                    ? const SizedBox(
                        width: 16,
                        height: 16,
                        child: CircularProgressIndicator(strokeWidth: 2),
                      )
                    : const Icon(Icons.power_settings_new),
                label: const Text('Wake Mac'),
              ),
              const SizedBox(height: 12),

              // Reset TLS Trust button
              OutlinedButton.icon(
                onPressed: () async {
                  final confirmed = await showDialog<bool>(
                    context: context,
                    builder: (ctx) => AlertDialog(
                      title: const Text('Reset Server Trust?'),
                      content: const Text(
                        'This clears the saved server certificate fingerprint. '
                        'Use this if you reinstalled AIBroker or changed servers. '
                        'The app will trust the next server it connects to.',
                      ),
                      actions: [
                        TextButton(
                          onPressed: () => Navigator.pop(ctx, false),
                          child: const Text('Cancel'),
                        ),
                        TextButton(
                          onPressed: () => Navigator.pop(ctx, true),
                          child: const Text('Reset', style: TextStyle(color: AppColors.error)),
                        ),
                      ],
                    ),
                  );
                  if (confirmed == true && mounted) {
                    // Access MqttService through the provider and reset trust
                    final prefs = await SharedPreferences.getInstance();
                    await prefs.remove('trustedCertFingerprint');
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(content: Text('Server trust reset. Reconnect to trust the new server.')),
                    );
                  }
                },
                icon: const Icon(Icons.shield_outlined),
                label: const Text('Reset Server Trust'),
              ),
              const SizedBox(height: 12),

              // Message Trace Log — for diagnosing message delivery problems
              OutlinedButton.icon(
                onPressed: () {
                  Navigator.of(context).push(
                    MaterialPageRoute<void>(
                      builder: (_) => const TraceScreen(),
                    ),
                  );
                },
                icon: const Icon(Icons.receipt_long_outlined),
                label: const Text('Message Trace Log'),
              ),
              const SizedBox(height: 24),

              // --- PAILot Pro ---
              const Divider(),
              const SizedBox(height: 8),
              Row(
                children: [
                  const Icon(Icons.star, size: 18),
                  const SizedBox(width: 8),
                  Text(
                    'PAILot Pro',
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                  const Spacer(),
                  Consumer(
                    builder: (ctx, ref, _) {
                      final isPro = ref.watch(isProProvider);
                      return Chip(
                        label: Text(
                          isPro ? 'Active' : 'Free Tier',
                          style: TextStyle(
                            fontSize: 11,
                            color: isPro ? Colors.white : null,
                          ),
                        ),
                        backgroundColor: isPro ? AppColors.accent : null,
                        padding: EdgeInsets.zero,
                        visualDensity: VisualDensity.compact,
                      );
                    },
                  ),
                ],
              ),
              const SizedBox(height: 4),
              Text(
                'Free: 2 sessions, messages expire after 15 min\n'
                'Pro: unlimited sessions, messages persist forever',
                style: Theme.of(context)
                    .textTheme
                    .bodySmall
                    ?.copyWith(color: Colors.grey.shade500),
              ),
              const SizedBox(height: 12),
              Consumer(
                builder: (ctx, ref, _) {
                  final isPro = ref.watch(isProProvider);
                  if (isPro) {
                    return const Center(
                      child: Text(
                        'Full access active',
                        style: TextStyle(color: AppColors.accent),
                      ),
                    );
                  }
                  return Column(
                    crossAxisAlignment: CrossAxisAlignment.stretch,
                    children: [
                      ElevatedButton.icon(
                        onPressed: _iapLoading ? null : _handleUpgrade,
                        icon: _iapLoading
                            ? const SizedBox(
                                width: 16,
                                height: 16,
                                child:
                                    CircularProgressIndicator(strokeWidth: 2),
                              )
                            : const Icon(Icons.upgrade),
                        label: const Text('Upgrade to Pro — \$4.99'),
                        style: ElevatedButton.styleFrom(
                          backgroundColor: AppColors.accent,
                          foregroundColor: Colors.white,
                        ),
                      ),
                      const SizedBox(height: 8),
                      OutlinedButton.icon(
                        onPressed: _iapLoading ? null : _handleRestore,
                        icon: const Icon(Icons.restore),
                        label: const Text('Restore Purchase'),
                      ),
                    ],
                  );
                },
              ),
              const SizedBox(height: 12),
            ],
          ),
        ),
      ),
    );
  }

  String _statusText(ConnectionStatus status) {
    switch (status) {
      case ConnectionStatus.connected:
        return 'Connected';
      case ConnectionStatus.connecting:
        return 'Connecting...';
      case ConnectionStatus.reconnecting:
        return 'Reconnecting...';
      case ConnectionStatus.disconnected:
        return 'Disconnected';
    }
  }
}