import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../services/app_state.dart';

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

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

class _SettingsScreenState extends State<SettingsScreen> {
  bool _changing = false;
  String? _error;

  Future<void> _chooseFolder() async {
    setState(() => _error = null);

    final selectedPath = await FilePicker.platform.getDirectoryPath(
      dialogTitle: 'Choose a folder for receipts and data',
    );
    if (selectedPath == null || !mounted) return;

    setState(() => _changing = true);
    try {
      await context.read<AppState>().changeSaveDirectory(selectedPath);
    } catch (e) {
      setState(() => _error = 'Could not switch to that folder: $e');
    } finally {
      if (mounted) setState(() => _changing = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final appState = context.watch<AppState>();
    final saveDir = appState.storage.saveDirectory.path;

    return Scaffold(
      appBar: AppBar(title: const Text('Settings')),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Card(
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('Save Location', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  Text(
                    'Receipt photos and the data file are stored here:',
                    style: Theme.of(context).textTheme.bodyMedium,
                  ),
                  const SizedBox(height: 4),
                  SelectableText(
                    saveDir,
                    style: Theme.of(context).textTheme.bodySmall?.copyWith(
                          fontFamily: 'monospace',
                        ),
                  ),
                  const SizedBox(height: 16),
                  if (_error != null) ...[
                    Text(_error!, style: TextStyle(color: Theme.of(context).colorScheme.error)),
                    const SizedBox(height: 8),
                  ],
                  FilledButton.icon(
                    onPressed: _changing ? null : _chooseFolder,
                    icon: _changing
                        ? const SizedBox(
                            height: 16,
                            width: 16,
                            child: CircularProgressIndicator(strokeWidth: 2),
                          )
                        : const Icon(Icons.folder_open),
                    label: const Text('Choose Folder'),
                  ),
                ],
              ),
            ),
          ),
          const SizedBox(height: 16),
          Card(
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('Summary', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  Text('${appState.vehicles.length} vehicle(s)'),
                  Text('${appState.fuelEntries.length} fuel entries'),
                  Text('${appState.totalGallonsAllVehicles.toStringAsFixed(3)} total gallons logged'),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}