import 'package:flutter/material.dart';
import 'relay_management_controller.dart';
import '../../data/nostr/models/nostr_relay.dart';
import '../../core/service_locator.dart';
import '../../data/local/models/item.dart';

/// Screen for managing Nostr relays.
/// 
/// Allows users to view, add, remove, test, and toggle relays.
class RelayManagementScreen extends StatefulWidget {
  /// Controller for managing relay state.
  final RelayManagementController controller;

  /// Creates a [RelayManagementScreen] instance.
  const RelayManagementScreen({
    super.key,
    required this.controller,
  });

  @override
  State<RelayManagementScreen> createState() => _RelayManagementScreenState();
}

class _RelayManagementScreenState extends State<RelayManagementScreen> {
  final TextEditingController _urlController = TextEditingController();
  bool _useNip05RelaysAutomatically = false;
  bool _isDarkMode = false;
  bool _isLoadingSetting = true;

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

  @override
  void dispose() {
    _urlController.dispose();
    super.dispose();
  }

  Future<void> _loadSetting() async {
    try {
      final localStorage = ServiceLocator.instance.localStorageService;
      if (localStorage == null) {
        setState(() {
          _isLoadingSetting = false;
        });
        return;
      }

      final settingsItem = await localStorage.getItem('app_settings');
      if (settingsItem != null) {
        final useNip05 = settingsItem.data['use_nip05_relays_automatically'] == true;
        final isDark = settingsItem.data['dark_mode'] == true;
        setState(() {
          _useNip05RelaysAutomatically = useNip05;
          _isDarkMode = isDark;
          _isLoadingSetting = false;
        });
        // Update theme notifier if available
        final themeNotifier = ServiceLocator.instance.themeNotifier;
        if (themeNotifier != null) {
          themeNotifier.setThemeMode(isDark ? ThemeMode.dark : ThemeMode.light);
        }
      } else {
        setState(() {
          _isLoadingSetting = false;
        });
      }
    } catch (e) {
      setState(() {
        _isLoadingSetting = false;
      });
    }
  }

  Future<void> _saveSetting(String key, bool value) async {
    try {
      final localStorage = ServiceLocator.instance.localStorageService;
      if (localStorage == null) return;

      final settingsItem = await localStorage.getItem('app_settings');
      final data = settingsItem?.data ?? <String, dynamic>{};
      data[key] = value;

      await localStorage.insertItem(Item(
        id: 'app_settings',
        data: data,
      ));

      setState(() {
        if (key == 'use_nip05_relays_automatically') {
          _useNip05RelaysAutomatically = value;
        } else if (key == 'dark_mode') {
          _isDarkMode = value;
          // Notify the app to update theme
          _updateAppTheme(value);
        }
      });
    } catch (e) {
      // Log error but don't show to user - setting will just not persist
    }
  }

  void _updateAppTheme(bool isDark) {
    // Update the theme notifier, which MyApp is listening to
    final themeNotifier = ServiceLocator.instance.themeNotifier;
    if (themeNotifier != null) {
      themeNotifier.setThemeMode(isDark ? ThemeMode.dark : ThemeMode.light);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Nostr Relay Management'),
      ),
      body: ListenableBuilder(
        listenable: widget.controller,
        builder: (context, child) {
          return Column(
            children: [
              // Settings section
              Container(
                width: double.infinity,
                padding: const EdgeInsets.all(16),
                decoration: BoxDecoration(
                  color: Theme.of(context).cardColor,
                  border: Border(
                    bottom: BorderSide(
                      color: Theme.of(context).dividerColor,
                      width: 1,
                    ),
                  ),
                ),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Settings',
                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 12),
                    if (_isLoadingSetting)
                      const Row(
                        children: [
                          SizedBox(
                            width: 16,
                            height: 16,
                            child: CircularProgressIndicator(strokeWidth: 2),
                          ),
                          SizedBox(width: 12),
                          Text('Loading settings...'),
                        ],
                      )
                    else
                      SwitchListTile(
                        title: const Text('Use NIP-05 relays automatically'),
                        subtitle: const Text(
                          'Automatically replace relays with NIP-05 preferred relays upon login',
                          style: TextStyle(fontSize: 12),
                        ),
                        value: _useNip05RelaysAutomatically,
                        onChanged: (value) {
                          _saveSetting('use_nip05_relays_automatically', value);
                        },
                        contentPadding: EdgeInsets.zero,
                      ),
                      const SizedBox(height: 8),
                      SwitchListTile(
                        title: const Text('Dark Mode'),
                        subtitle: const Text(
                          'Enable dark theme for the app',
                          style: TextStyle(fontSize: 12),
                        ),
                        value: _isDarkMode,
                        onChanged: (value) {
                          _saveSetting('dark_mode', value);
                        },
                        contentPadding: EdgeInsets.zero,
                      ),
                  ],
                ),
              ),
              // Error message
              if (widget.controller.error != null)
                Container(
                  width: double.infinity,
                  padding: const EdgeInsets.all(16),
                  color: Colors.red.shade100,
                  child: Row(
                    children: [
                      Icon(Icons.error, color: Colors.red.shade700),
                      const SizedBox(width: 8),
                      Expanded(
                        child: Text(
                          widget.controller.error!,
                          style: TextStyle(color: Colors.red.shade700),
                        ),
                      ),
                      IconButton(
                        icon: const Icon(Icons.close),
                        onPressed: widget.controller.clearError,
                        color: Colors.red.shade700,
                      ),
                    ],
                  ),
                ),

              // Top action buttons
              Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    // Test All and Toggle All buttons
                    Row(
                      children: [
                        Expanded(
                          child: ElevatedButton.icon(
                            onPressed: widget.controller.isCheckingHealth
                                ? null
                                : widget.controller.checkRelayHealth,
                            icon: widget.controller.isCheckingHealth
                                ? const SizedBox(
                                    width: 16,
                                    height: 16,
                                    child: CircularProgressIndicator(strokeWidth: 2),
                                  )
                                : const Icon(Icons.network_check),
                            label: const Text('Test All'),
                          ),
                        ),
                        const SizedBox(width: 8),
                        Expanded(
                          child: ElevatedButton.icon(
                            onPressed: widget.controller.relays.isEmpty
                                ? null
                                : () async {
                                    await widget.controller.toggleAllRelays();
                                  },
                            icon: const Icon(Icons.power_settings_new),
                            label: Text(
                              widget.controller.relays.isNotEmpty &&
                                      widget.controller.relays.every((r) => r.isEnabled)
                                  ? 'Turn All Off'
                                  : 'Turn All On',
                            ),
                          ),
                        ),
                      ],
                    ),
                    const SizedBox(height: 16),
                    // Add relay input
                    Row(
                      children: [
                        Expanded(
                          child: TextField(
                            controller: _urlController,
                            decoration: InputDecoration(
                              labelText: 'Relay URL',
                              hintText: 'wss://relay.example.com',
                              border: const OutlineInputBorder(),
                            ),
                            keyboardType: TextInputType.url,
                          ),
                        ),
                        const SizedBox(width: 8),
                        ElevatedButton.icon(
                          onPressed: () async {
                            final url = _urlController.text.trim();
                            if (url.isNotEmpty) {
                              final success = await widget.controller.addRelay(url);
                              if (mounted) {
                                if (success) {
                                  _urlController.clear();
                                  ScaffoldMessenger.of(context).showSnackBar(
                                    const SnackBar(
                                      content: Text('Relay added and connected successfully'),
                                      backgroundColor: Colors.green,
                                      duration: Duration(seconds: 1),
                                    ),
                                  );
                                } else {
                                  ScaffoldMessenger.of(context).showSnackBar(
                                    SnackBar(
                                      content: Text(
                                        widget.controller.error ?? 'Failed to connect to relay',
                                      ),
                                      backgroundColor: Colors.orange,
                                      duration: const Duration(seconds: 3),
                                    ),
                                  );
                                }
                              }
                            }
                          },
                          icon: const Icon(Icons.add),
                          label: const Text('Add'),
                        ),
                      ],
                    ),
                  ],
                ),
              ),

              const Divider(),

              // Relay list
              Expanded(
                child: widget.controller.relays.isEmpty
                    ? Center(
                        child: Column(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            Icon(
                              Icons.cloud_off,
                              size: 64,
                              color: Colors.grey.shade400,
                            ),
                            const SizedBox(height: 16),
                            Text(
                              'No relays configured',
                              style: Theme.of(context).textTheme.titleLarge?.copyWith(
                                    color: Colors.grey,
                                  ),
                            ),
                            const SizedBox(height: 8),
                            Text(
                              'Add a relay to get started',
                              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                                    color: Colors.grey,
                                  ),
                            ),
                          ],
                        ),
                      )
                    : ListView.builder(
                        itemCount: widget.controller.relays.length,
                        itemBuilder: (context, index) {
                          final relay = widget.controller.relays[index];
                          return _RelayListItem(
                            relay: relay,
                            onToggle: () async {
                              await widget.controller.toggleRelay(relay.url);
                            },
                            onRemove: () {
                              widget.controller.removeRelay(relay.url);
                              ScaffoldMessenger.of(context).showSnackBar(
                                SnackBar(
                                  content: Text('Relay ${relay.url} removed'),
                                  duration: const Duration(seconds: 2),
                                ),
                              );
                            },
                          );
                        },
                      ),
              ),
            ],
          );
        },
      ),
    );
  }
}

/// Widget for displaying a single relay in the list.
class _RelayListItem extends StatelessWidget {
  /// The relay to display.
  final NostrRelay relay;

  /// Callback when toggle is pressed.
  final VoidCallback onToggle;

  /// Callback when remove is pressed.
  final VoidCallback onRemove;

  const _RelayListItem({
    required this.relay,
    required this.onToggle,
    required this.onRemove,
  });

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        child: Row(
          children: [
            // Status indicator
            Container(
              width: 10,
              height: 10,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                color: relay.isConnected && relay.isEnabled
                    ? Colors.green
                    : Colors.grey,
              ),
            ),
            const SizedBox(width: 8),
            // URL and status text
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text(
                    relay.url,
                    style: const TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w500,
                    ),
                    overflow: TextOverflow.ellipsis,
                    maxLines: 1,
                  ),
                  const SizedBox(height: 2),
                  Text(
                    relay.isConnected && relay.isEnabled
                        ? 'Connected'
                        : 'Disabled',
                    style: TextStyle(
                      fontSize: 11,
                      color: relay.isConnected && relay.isEnabled
                          ? Colors.green
                          : Colors.grey,
                    ),
                  ),
                ],
              ),
            ),
            const SizedBox(width: 8),
            // Toggle switch
            Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(
                  relay.isEnabled ? 'ON' : 'OFF',
                  style: TextStyle(
                    fontSize: 11,
                    fontWeight: FontWeight.w500,
                    color: relay.isEnabled
                        ? Colors.green
                        : Colors.grey[600],
                  ),
                ),
                const SizedBox(width: 4),
                Transform.scale(
                  scale: 0.8,
                  child: Switch(
                    value: relay.isEnabled,
                    onChanged: (_) => onToggle(),
                  ),
                ),
              ],
            ),
            const SizedBox(width: 4),
            // Remove button
            IconButton(
              icon: const Icon(Icons.delete, size: 18),
              color: Colors.red,
              tooltip: 'Remove',
              onPressed: onRemove,
              padding: EdgeInsets.zero,
              constraints: const BoxConstraints(
                minWidth: 32,
                minHeight: 32,
              ),
            ),
          ],
        ),
      ),
    );
  }
}