import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:flutter_colorpicker/flutter_colorpicker.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../l10n/app_localizations.dart';
import '../models/pen_tool.dart';
import '../models/pressure_curve.dart';
import '../providers/settings_provider.dart';
import '../services/vault_service.dart';
import '../utils/stroke_stabilizer.dart';

/// Material 3 settings screen for BadNote.
class SettingsScreen extends ConsumerWidget {
  const SettingsScreen({super.key});

  void _showColorPicker(
    BuildContext context,
    Color current,
    ValueChanged<Color> onPicked,
  ) {
    Color pickerColor = current;
    showDialog(
      context: context,
      builder: (context) {
        final l = AppLocalizations.of(context);
        return AlertDialog(
          title: Text(l.pickColor),
          content: SingleChildScrollView(
            child: ColorPicker(
              pickerColor: pickerColor,
              onColorChanged: (color) => pickerColor = color,
            ),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(context).pop(),
              child: Text(l.cancel),
            ),
            TextButton(
              onPressed: () {
                onPicked(pickerColor);
                Navigator.of(context).pop();
              },
              child: Text(l.ok),
            ),
          ],
        );
      },
    );
  }

  void _confirmClearData(BuildContext context, WidgetRef ref) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: Text(AppLocalizations.of(ctx).clearSettingsTitle),
        content: const Text(
          'This will reset pen defaults and appearance settings. '
          'Notes and documents are not affected.',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: Text(AppLocalizations.of(ctx).cancel),
          ),
          TextButton(
            onPressed: () {
              ref.read(settingsProvider).clearAllData();
              Navigator.pop(ctx);
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(
                    content: Text(AppLocalizations.of(context).settingsReset)),
              );
            },
            child: Text(AppLocalizations.of(ctx).clear),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final settings = ref.watch(settingsProvider);
    final colorScheme = Theme.of(context).colorScheme;

    return Scaffold(
      appBar: AppBar(title: Text(AppLocalizations.of(context).settings)),
      body: ListView(
        children: [
          _SectionHeader(title: 'Defaults', icon: Icons.tune),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text(
                  'Default Tool',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                DropdownButtonFormField<PenTool>(
                  initialValue: settings.defaultTool,
                  decoration: const InputDecoration(
                    border: OutlineInputBorder(),
                    isDense: true,
                  ),
                  items: PenTool.values.map((tool) {
                    return DropdownMenuItem(
                      value: tool,
                      child: Text(tool.name),
                    );
                  }).toList(),
                  onChanged: (tool) {
                    if (tool != null) settings.setDefaultTool(tool);
                  },
                ),
                const SizedBox(height: 16),
                const Text(
                  'Default Color',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                Row(
                  children: [
                    MouseRegion(
                      cursor: SystemMouseCursors.click,
                      child: InkWell(
                        borderRadius: BorderRadius.circular(8),
                        onTap: () => _showColorPicker(
                          context,
                          settings.defaultColor,
                          settings.setDefaultColor,
                        ),
                        child: Container(
                          width: 40,
                          height: 40,
                          decoration: BoxDecoration(
                            color: settings.defaultColor,
                            borderRadius: BorderRadius.circular(8),
                            border: Border.all(color: colorScheme.outline),
                          ),
                        ),
                      ),
                    ),
                    const SizedBox(width: 12),
                    Text(
                      '#${settings.defaultColor.toARGB32().toRadixString(16).padLeft(8, '0').toUpperCase()}',
                      style: const TextStyle(fontFamily: 'monospace'),
                    ),
                  ],
                ),
                const SizedBox(height: 16),
                const Text(
                  'Default Stroke Width',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                Slider(
                  value: settings.defaultStrokeWidth,
                  min: 1.0,
                  max: 20.0,
                  divisions: 19,
                  label: settings.defaultStrokeWidth.toStringAsFixed(1),
                  onChanged: settings.setDefaultStrokeWidth,
                ),
                const SizedBox(height: 16),
                const Text(
                  'Pressure Curve',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                DropdownButtonFormField<PressureCurveType>(
                  initialValue: settings.defaultPressureCurve,
                  decoration: const InputDecoration(
                    border: OutlineInputBorder(),
                    isDense: true,
                  ),
                  items: PressureCurveType.values.map((curve) {
                    return DropdownMenuItem(
                      value: curve,
                      child: Text(curve.name),
                    );
                  }).toList(),
                  onChanged: (curve) {
                    if (curve != null) {
                      settings.setDefaultPressureCurve(curve);
                    }
                  },
                ),
                const SizedBox(height: 16),
                const Text(
                  'Stabilization',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                DropdownButtonFormField<StabilizationLevel>(
                  initialValue: settings.defaultStabilization,
                  decoration: const InputDecoration(
                    border: OutlineInputBorder(),
                    isDense: true,
                  ),
                  items: StabilizationLevel.values.map((level) {
                    return DropdownMenuItem(
                      value: level,
                      child: Text(level.name),
                    );
                  }).toList(),
                  onChanged: (level) {
                    if (level != null) settings.setDefaultStabilization(level);
                  },
                ),
              ],
            ),
          ),
          const Divider(),
          _SectionHeader(title: 'Appearance', icon: Icons.palette),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text(
                  'Theme Mode',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                SegmentedButton<ThemeMode>(
                  segments: [
                    ButtonSegment(
                      value: ThemeMode.system,
                      label: Text(AppLocalizations.of(context).themeSystem),
                      icon: const Icon(Icons.brightness_auto),
                    ),
                    ButtonSegment(
                      value: ThemeMode.light,
                      label: Text(AppLocalizations.of(context).themeLight),
                      icon: const Icon(Icons.light_mode),
                    ),
                    ButtonSegment(
                      value: ThemeMode.dark,
                      label: Text(AppLocalizations.of(context).themeDark),
                      icon: const Icon(Icons.dark_mode),
                    ),
                  ],
                  selected: {settings.themeMode},
                  onSelectionChanged: (modes) {
                    settings.setThemeMode(modes.first);
                  },
                ),
                const SizedBox(height: 16),
                const Text(
                  'Color Scheme Seed',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                Row(
                  children: [
                    MouseRegion(
                      cursor: SystemMouseCursors.click,
                      child: InkWell(
                        borderRadius: BorderRadius.circular(8),
                        onTap: () => _showColorPicker(
                          context,
                          settings.colorSchemeSeed,
                          settings.setColorSchemeSeed,
                        ),
                        child: Container(
                          width: 40,
                          height: 40,
                          decoration: BoxDecoration(
                            color: settings.colorSchemeSeed,
                            borderRadius: BorderRadius.circular(8),
                            border: Border.all(color: colorScheme.outline),
                          ),
                        ),
                      ),
                    ),
                    const SizedBox(width: 12),
                    Text(AppLocalizations.of(context).seedColorDesc),
                  ],
                ),
              ],
            ),
          ),
          const Divider(),
          _SectionHeader(title: 'Vault', icon: Icons.folder_special),
          const Padding(
            padding: EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: _VaultSettings(),
          ),
          const Divider(),
          _SectionHeader(title: 'About', icon: Icons.info),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text(
                  'BadNote v0.1.0',
                  style: TextStyle(fontWeight: FontWeight.w500),
                ),
                const SizedBox(height: 4),
                Text(
                  'Local-first Surface Pen note-taking with PDF/PPT annotation. '
                  'OCR and search run entirely on your device.',
                  style: TextStyle(
                    fontSize: 13,
                    color: colorScheme.onSurfaceVariant,
                  ),
                ),
                const SizedBox(height: 16),
                OutlinedButton.icon(
                  onPressed: () => _confirmClearData(context, ref),
                  icon: const Icon(Icons.delete_forever, color: Colors.red),
                  label: const Text(
                    'Clear All Local Settings',
                    style: TextStyle(color: Colors.red),
                  ),
                ),
              ],
            ),
          ),
          const SizedBox(height: 32),
        ],
      ),
    );
  }
}

/// Shows the current vault folder path and lets the user re-pick it. Re-uses
/// the same `getDirectoryPath` flow as the first-run [VaultSetupScreen],
/// persisting the choice through [VaultService.setVaultRoot].
class _VaultSettings extends StatefulWidget {
  const _VaultSettings();

  @override
  State<_VaultSettings> createState() => _VaultSettingsState();
}

class _VaultSettingsState extends State<_VaultSettings> {
  VaultService? _vault;
  String? _path;
  bool _busy = false;

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

  Future<void> _load() async {
    final vault = await VaultService.getInstance();
    if (!mounted) return;
    setState(() {
      _vault = vault;
      _path = vault.vaultRoot;
    });
  }

  Future<void> _changeFolder() async {
    final vault = _vault;
    if (vault == null) return;
    final l = AppLocalizations.of(context);
    final messenger = ScaffoldMessenger.of(context);
    setState(() => _busy = true);
    try {
      final path = await FilePicker.platform.getDirectoryPath(
        dialogTitle: l.vaultSetupTitle,
        lockParentWindow: true,
      );
      if (path != null) {
        await vault.setVaultRoot(path);
        if (!mounted) return;
        setState(() => _path = path);
        messenger.showSnackBar(SnackBar(content: Text(l.vaultUpdated)));
      }
    } catch (e) {
      if (!mounted) return;
      messenger.showSnackBar(
        SnackBar(content: Text(l.vaultPickFailed(e.toString()))),
      );
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context);
    final colorScheme = Theme.of(context).colorScheme;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          l.vaultFolderLabel,
          style: const TextStyle(fontWeight: FontWeight.w500),
        ),
        const SizedBox(height: 4),
        Text(
          (_path == null || _path!.isEmpty) ? l.vaultNoneSelected : _path!,
          style: TextStyle(
            fontSize: 13,
            color: colorScheme.onSurfaceVariant,
          ),
        ),
        const SizedBox(height: 12),
        OutlinedButton.icon(
          onPressed: _busy ? null : _changeFolder,
          icon: const Icon(Icons.drive_folder_upload),
          label: Text(l.vaultChangeFolder),
        ),
      ],
    );
  }
}

class _SectionHeader extends StatelessWidget {
  final String title;
  final IconData icon;

  const _SectionHeader({required this.title, required this.icon});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 16, 16, 4),
      child: Row(
        children: [
          Icon(icon, size: 20, color: Theme.of(context).colorScheme.primary),
          const SizedBox(width: 8),
          Text(
            title,
            style: Theme.of(
              context,
            ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.bold),
          ),
        ],
      ),
    );
  }
}