import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import 'package:environment_monitoring_app/auth_provider.dart';
import 'package:environment_monitoring_app/services/settings_service.dart';

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

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

class _SettingsScreenState extends State<SettingsScreen> {
  // SettingsService is now a utility, it doesn't hold state.
  final SettingsService _settingsService = SettingsService();
  bool _isSyncingData = false;

  // REMOVED: Redundant state variable for settings sync
  // bool _isSyncingSettings = false;

  // REMOVED: Chat ID state variables are no longer needed,
  // we will read directly from the provider in the build method.

  final TextEditingController _tarballSearchController = TextEditingController();
  String _tarballSearchQuery = '';
  final TextEditingController _manualSearchController = TextEditingController();
  String _manualSearchQuery = '';
  final TextEditingController _riverManualSearchController = TextEditingController();
  String _riverManualSearchQuery = '';
  final TextEditingController _riverTriennialSearchController = TextEditingController();
  String _riverTriennialSearchQuery = '';

  @override
  void initState() {
    super.initState();
    // REMOVED: _loadCurrentSettings() is no longer needed as we read from the provider.
    _tarballSearchController.addListener(_onTarballSearchChanged);
    _manualSearchController.addListener(_onManualSearchChanged);
    _riverManualSearchController.addListener(_onRiverManualSearchChanged);
    _riverTriennialSearchController.addListener(_onRiverTriennialSearchChanged);
  }

  @override
  void dispose() {
    _tarballSearchController.dispose();
    _manualSearchController.dispose();
    _riverManualSearchController.dispose();
    _riverTriennialSearchController.dispose();
    super.dispose();
  }

  // REMOVED: _loadCurrentSettings is obsolete. The build method will now
  // get the latest settings directly from AuthProvider.

  void _onTarballSearchChanged() {
    setState(() { _tarballSearchQuery = _tarballSearchController.text; });
  }

  void _onManualSearchChanged() {
    setState(() { _manualSearchQuery = _manualSearchController.text; });
  }

  void _onRiverManualSearchChanged() {
    setState(() { _riverManualSearchQuery = _riverManualSearchController.text; });
  }

  void _onRiverTriennialSearchChanged() {
    setState(() { _riverTriennialSearchQuery = _riverTriennialSearchController.text; });
  }

  Future<void> _manualDataSync() async {
    if (_isSyncingData) return;
    setState(() => _isSyncingData = true);

    final auth = Provider.of<AuthProvider>(context, listen: false);

    try {
      // This now syncs ALL data, including settings.
      await auth.syncAllData(forceRefresh: true);

      if (mounted) {
        _showSnackBar('Data synced successfully.', isError: false);
      }
    } catch (e) {
      if (mounted) {
        _showSnackBar('Data sync failed. Please check your connection.', isError: true);
      }
    } finally {
      if (mounted) {
        setState(() => _isSyncingData = false);
      }
    }
  }

  // REMOVED: _manualSettingsSync is obsolete because the main data sync
  // now handles settings as well.

  void _showSnackBar(String message, {bool isError = false}) {
    if (mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(message),
          backgroundColor: isError ? Theme.of(context).colorScheme.error : Colors.green,
        ),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    final auth = Provider.of<AuthProvider>(context);
    final lastSync = auth.lastSyncTimestamp;

    // Get the synced app settings from the provider.
    final appSettings = auth.appSettings;

    final filteredTarballStations = auth.tarballStations?.where((station) {
      final stationName = station['tbl_station_name']?.toLowerCase() ?? '';
      final stationCode = station['tbl_station_code']?.toLowerCase() ?? '';
      final query = _tarballSearchQuery.toLowerCase();
      return stationName.contains(query) || stationCode.contains(query);
    }).toList();
    final filteredManualStations = auth.manualStations?.where((station) {
      final stationName = station['man_station_name']?.toLowerCase() ?? '';
      final stationCode = station['man_station_code']?.toLowerCase() ?? '';
      final query = _manualSearchQuery.toLowerCase();
      return stationName.contains(query) || stationCode.contains(query);
    }).toList();
    final filteredRiverManualStations = auth.riverManualStations?.where((station) {
      final riverName = station['sampling_river']?.toLowerCase() ?? '';
      final stationCode = station['sampling_station_code']?.toLowerCase() ?? '';
      final basinName = station['sampling_basin']?.toLowerCase() ?? '';
      final query = _riverManualSearchQuery.toLowerCase();
      return riverName.contains(query) || stationCode.contains(query) || basinName.contains(query);
    }).toList();
    final filteredRiverTriennialStations = auth.riverTriennialStations?.where((station) {
      final riverName = station['triennial_river']?.toLowerCase() ?? '';
      final stationCode = station['triennial_station_code']?.toLowerCase() ?? '';
      final basinName = station['triennial_basin']?.toLowerCase() ?? '';
      final query = _riverTriennialSearchQuery.toLowerCase();
      return riverName.contains(query) || stationCode.contains(query) || basinName.contains(query);
    }).toList();

    return Scaffold(
      appBar: AppBar(
        title: const Text("Settings"),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(24.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text("Synchronization", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    Text("Last Data Sync:", style: Theme.of(context).textTheme.titleMedium),
                    const SizedBox(height: 4),
                    Text(lastSync != null ? DateFormat('yyyy-MM-dd HH:mm:ss').format(lastSync.toLocal()) : 'Never', style: Theme.of(context).textTheme.bodyLarge),
                    const SizedBox(height: 16),
                    ElevatedButton.icon(
                      onPressed: _isSyncingData ? null : _manualDataSync,
                      icon: _isSyncingData ? const SizedBox(width: 20, height: 20, child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white)) : const Icon(Icons.cloud_sync),
                      label: Text(_isSyncingData ? 'Syncing Data...' : 'Sync App Data'),
                      style: ElevatedButton.styleFrom(minimumSize: const Size(double.infinity, 50)),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            Text("Telegram Alert Settings", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  children: [
                    ExpansionTile(
                      title: const Text('Marine Alerts', style: TextStyle(fontWeight: FontWeight.bold)),
                      initiallyExpanded: false,
                      children: [
                        _buildChatIdEntry('In-Situ', _settingsService.getInSituChatId(appSettings)),
                        _buildChatIdEntry('Tarball', _settingsService.getTarballChatId(appSettings)),
                        _buildChatIdEntry('Investigative', _settingsService.getMarineInvestigativeChatId(appSettings)),
                      ],
                    ),
                    ExpansionTile(
                      title: const Text('River Alerts', style: TextStyle(fontWeight: FontWeight.bold)),
                      initiallyExpanded: false,
                      children: [
                        _buildChatIdEntry('In-Situ', _settingsService.getRiverInSituChatId(appSettings)),
                        _buildChatIdEntry('Triennial', _settingsService.getRiverTriennialChatId(appSettings)),
                        _buildChatIdEntry('Investigative', _settingsService.getRiverInvestigativeChatId(appSettings)),
                      ],
                    ),
                    ExpansionTile(
                      title: const Text('Air Alerts', style: TextStyle(fontWeight: FontWeight.bold)),
                      initiallyExpanded: false,
                      children: [
                        _buildChatIdEntry('Manual', _settingsService.getAirManualChatId(appSettings)),
                        _buildChatIdEntry('Investigative', _settingsService.getAirInvestigativeChatId(appSettings)),
                      ],
                    ),
                    // REMOVED: The separate sync button for settings is no longer needed.
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            Text("Marine Tarball Stations (${filteredTarballStations?.length ?? 0})", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  children: [
                    TextField(
                      controller: _tarballSearchController,
                      decoration: InputDecoration(
                        labelText: 'Search Tarball Stations',
                        hintText: 'Search by name or code',
                        prefixIcon: const Icon(Icons.search),
                        border: OutlineInputBorder(borderRadius: BorderRadius.circular(8.0)),
                        suffixIcon: _tarballSearchController.text.isNotEmpty ? IconButton(icon: const Icon(Icons.clear), onPressed: () => _tarballSearchController.clear()) : null,
                      ),
                    ),
                    const SizedBox(height: 16),
                    _buildStationList(
                      filteredTarballStations,
                      'No matching tarball stations found.',
                      'No tarball stations available. Sync to download.',
                          (station) => ListTile(
                        title: Text(station['tbl_station_name'] ?? 'N/A'),
                        subtitle: Text('Code: ${station['tbl_station_code'] ?? 'N/A'}'),
                        dense: true,
                      ),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            Text("Marine Manual Stations (${filteredManualStations?.length ?? 0})", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  children: [
                    TextField(
                      controller: _manualSearchController,
                      decoration: InputDecoration(
                        labelText: 'Search Manual Stations',
                        hintText: 'Search by name or code',
                        prefixIcon: const Icon(Icons.search),
                        border: OutlineInputBorder(borderRadius: BorderRadius.circular(8.0)),
                        suffixIcon: _manualSearchController.text.isNotEmpty ? IconButton(icon: const Icon(Icons.clear), onPressed: () => _manualSearchController.clear()) : null,
                      ),
                    ),
                    const SizedBox(height: 16),
                    _buildStationList(
                      filteredManualStations,
                      'No matching manual stations found.',
                      'No manual stations available. Sync to download.',
                          (station) => ListTile(
                        title: Text(station['man_station_name'] ?? 'N/A'),
                        subtitle: Text('Code: ${station['man_station_code'] ?? 'N/A'}'),
                        dense: true,
                      ),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            Text("River Manual Stations (${filteredRiverManualStations?.length ?? 0})", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  children: [
                    TextField(
                      controller: _riverManualSearchController,
                      decoration: InputDecoration(
                        labelText: 'Search River Manual Stations',
                        hintText: 'Search by river, basin, or code',
                        prefixIcon: const Icon(Icons.search),
                        border: OutlineInputBorder(borderRadius: BorderRadius.circular(8.0)),
                        suffixIcon: _riverManualSearchController.text.isNotEmpty ? IconButton(icon: const Icon(Icons.clear), onPressed: () => _riverManualSearchController.clear()) : null,
                      ),
                    ),
                    const SizedBox(height: 16),
                    _buildStationList(
                      filteredRiverManualStations,
                      'No matching river manual stations found.',
                      'No river manual stations available. Sync to download.',
                          (station) => ListTile(
                        title: Text(station['sampling_river'] ?? 'N/A'),
                        subtitle: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text('Code: ${station['sampling_station_code'] ?? 'N/A'}'),
                            Text('Basin: ${station['sampling_basin'] ?? 'N/A'}'),
                            Text('State: ${station['state_name'] ?? 'N/A'}'),
                          ],
                        ),
                        dense: true,
                      ),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            Text("River Triennial Stations (${filteredRiverTriennialStations?.length ?? 0})", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  children: [
                    TextField(
                      controller: _riverTriennialSearchController,
                      decoration: InputDecoration(
                        labelText: 'Search River Triennial Stations',
                        hintText: 'Search by river, basin, or code',
                        prefixIcon: const Icon(Icons.search),
                        border: OutlineInputBorder(borderRadius: BorderRadius.circular(8.0)),
                        suffixIcon: _riverTriennialSearchController.text.isNotEmpty ? IconButton(icon: const Icon(Icons.clear), onPressed: () => _riverTriennialSearchController.clear()) : null,
                      ),
                    ),
                    const SizedBox(height: 16),
                    _buildStationList(
                      filteredRiverTriennialStations,
                      'No matching river triennial stations found.',
                      'No river triennial stations available. Sync to download.',
                          (station) => ListTile(
                        title: Text(station['triennial_river'] ?? 'N/A'),
                        subtitle: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text('Code: ${station['triennial_station_code'] ?? 'N/A'}'),
                            Text('Basin: ${station['triennial_basin'] ?? 'N/A'}'),
                            Text('State: ${station['state_name'] ?? 'N/A'}'),
                          ],
                        ),
                        dense: true,
                      ),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            Text("General Settings", style: Theme.of(context).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            Card(
              margin: EdgeInsets.zero,
              child: Column(
                children: [
                  ListTile(
                    leading: const Icon(Icons.info_outline),
                    title: const Text('App Version'),
                    subtitle: const Text('1.2.03'),
                    dense: true,
                  ),
                  ListTile(
                    leading: const Icon(Icons.privacy_tip_outlined),
                    title: const Text('Privacy Policy'),
                    onTap: () {},
                    dense: true,
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildStationList(
      List<Map<String, dynamic>>? stations,
      String noMatchText,
      String noDataText,
      Widget Function(Map<String, dynamic>) itemBuilder,
      ) {
    if (stations == null || stations.isEmpty) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Text(
            _isSyncingData ? 'Loading...' : (stations == null ? noDataText : noMatchText),
          ),
        ),
      );
    }

    return SizedBox(
      height: 250,
      child: ListView.builder(
        itemCount: stations.length,
        itemBuilder: (context, index) {
          final station = stations[index];
          return itemBuilder(station);
        },
      ),
    );
  }

  Widget _buildChatIdEntry(String label, String value) {
    return ListTile(
      contentPadding: EdgeInsets.zero,
      leading: const Icon(Icons.telegram, size: 20),
      title: Text('$label Chat ID'),
      subtitle: Text(value.isNotEmpty ? value : 'Not Set'),
      dense: true,
    );
  }
}