import 'dart:developer' as developer;

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:tatlock_ui/core/auth/auth_provider.dart';
import 'package:tatlock_ui/core/theme/theme_provider.dart';
import 'package:tatlock_ui/routing/room_registry.dart';

/// Settings page with user preferences.
class SettingsPage extends ConsumerWidget {
  const SettingsPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final authState = ref.watch(authProvider);
    final currentTheme = ref.watch(themeProvider);
    final colorScheme = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;

    return Scaffold(
      body: authState.when(
        data: (auth) => SingleChildScrollView(
          padding: const EdgeInsets.all(24),
          child: Center(
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 600),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  // Page header
                  Text(
                    'Settings',
                    style: textTheme.headlineMedium,
                  ),
                  const SizedBox(height: 32),

                  // Appearance section
                  _SectionHeader(title: 'Appearance'),
                  const SizedBox(height: 8),
                  Card(
                    child: Padding(
                      padding: const EdgeInsets.all(16),
                      child: Row(
                        children: [
                          Icon(
                            _themeIcon(currentTheme),
                            color: colorScheme.onSurfaceVariant,
                          ),
                          const SizedBox(width: 16),
                          Expanded(
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text('Theme', style: textTheme.titleMedium),
                                Text(
                                  'Choose your preferred color scheme',
                                  style: textTheme.bodySmall?.copyWith(
                                    color: colorScheme.onSurfaceVariant,
                                  ),
                                ),
                              ],
                            ),
                          ),
                          DropdownButton<ThemeSetting>(
                            value: currentTheme,
                            underline: const SizedBox(),
                            onChanged: (value) {
                              if (value != null) {
                                _updateTheme(ref, value);
                              }
                            },
                            items: const [
                              DropdownMenuItem(
                                value: ThemeSetting.system,
                                child: Text('System'),
                              ),
                              DropdownMenuItem(
                                value: ThemeSetting.light,
                                child: Text('Light'),
                              ),
                              DropdownMenuItem(
                                value: ThemeSetting.dark,
                                child: Text('Dark'),
                              ),
                            ],
                          ),
                        ],
                      ),
                    ),
                  ),

                  const SizedBox(height: 24),

                  // Navigation section
                  _SectionHeader(title: 'Navigation'),
                  const SizedBox(height: 8),
                  Card(
                    child: Padding(
                      padding: const EdgeInsets.all(16),
                      child: Row(
                        children: [
                          Icon(
                            Icons.home_outlined,
                            color: colorScheme.onSurfaceVariant,
                          ),
                          const SizedBox(width: 16),
                          Expanded(
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text(
                                  'Default Room',
                                  style: textTheme.titleMedium,
                                ),
                                Text(
                                  'Room to show when app opens',
                                  style: textTheme.bodySmall?.copyWith(
                                    color: colorScheme.onSurfaceVariant,
                                  ),
                                ),
                              ],
                            ),
                          ),
                          DropdownButton<String>(
                            value:
                                auth.preferences?.defaultRoom ?? 'front-hall',
                            underline: const SizedBox(),
                            onChanged: (value) {
                              if (value != null) {
                                _updateDefaultRoom(ref, value);
                              }
                            },
                            items: roomRegistry.all
                                .map(
                                  (room) => DropdownMenuItem(
                                    value: room.id,
                                    child: Text(room.label),
                                  ),
                                )
                                .toList(),
                          ),
                        ],
                      ),
                    ),
                  ),

                  const SizedBox(height: 24),

                  // Account section
                  _SectionHeader(title: 'Account'),
                  const SizedBox(height: 8),
                  Card(
                    child: Column(
                      children: [
                        _AccountInfoTile(
                          icon: Icons.person_outline,
                          label: 'Name',
                          value: auth.userName ?? 'Not available',
                        ),
                        const Divider(height: 1),
                        _AccountInfoTile(
                          icon: Icons.email_outlined,
                          label: 'Email',
                          value: auth.userEmail ?? 'Not available',
                        ),
                        if (auth.roles.isNotEmpty) ...[
                          const Divider(height: 1),
                          _AccountInfoTile(
                            icon: Icons.shield_outlined,
                            label: 'Roles',
                            value: auth.roles.map((r) => r.name).join(', '),
                          ),
                        ],
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (error, _) => Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(Icons.error_outline, size: 48, color: colorScheme.error),
              const SizedBox(height: 16),
              Text(
                'Failed to load settings',
                style: textTheme.titleMedium,
              ),
              const SizedBox(height: 8),
              Text(
                error.toString(),
                style: textTheme.bodySmall?.copyWith(
                  color: colorScheme.onSurfaceVariant,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  IconData _themeIcon(ThemeSetting theme) {
    return switch (theme) {
      ThemeSetting.system => Icons.brightness_auto,
      ThemeSetting.light => Icons.light_mode,
      ThemeSetting.dark => Icons.dark_mode,
    };
  }

  Future<void> _updateTheme(WidgetRef ref, ThemeSetting setting) async {
    // Update local theme immediately for instant UI response
    await ref.read(themeProvider.notifier).setSetting(setting);

    // Sync to backend
    try {
      await ref.read(authProvider.notifier).updatePreferences(
            theme: setting.name,
          );
    } catch (e) {
      developer.log('Failed to sync theme preference: $e', name: 'settings');
    }
  }

  Future<void> _updateDefaultRoom(WidgetRef ref, String room) async {
    try {
      await ref.read(authProvider.notifier).updatePreferences(
            defaultRoom: room,
          );
    } catch (e) {
      developer.log('Failed to sync default room: $e', name: 'settings');
    }
  }
}

/// Section header widget.
class _SectionHeader extends StatelessWidget {
  const _SectionHeader({required this.title});

  final String title;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;

    return Text(
      title.toUpperCase(),
      style: textTheme.labelMedium?.copyWith(
        color: colorScheme.primary,
        letterSpacing: 1.0,
        fontWeight: FontWeight.w600,
      ),
    );
  }
}

/// Account info tile widget.
class _AccountInfoTile extends StatelessWidget {
  const _AccountInfoTile({
    required this.icon,
    required this.label,
    required this.value,
  });

  final IconData icon;
  final String label;
  final String value;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;

    return Padding(
      padding: const EdgeInsets.all(16),
      child: Row(
        children: [
          Icon(icon, color: colorScheme.onSurfaceVariant),
          const SizedBox(width: 16),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(label, style: textTheme.bodySmall?.copyWith(
                  color: colorScheme.onSurfaceVariant,
                )),
                const SizedBox(height: 2),
                Text(value, style: textTheme.titleMedium),
              ],
            ),
          ),
        ],
      ),
    );
  }
}