import 'package:flutter/material.dart';
import 'package:intl/intl.dart';

import 'package:askiineverdie/src/core/storage/save_service.dart'
    show SaveFileInfo;

/// 저장 파일 선택 다이얼로그
/// 선택된 파일명을 반환하거나, 취소 시 null 반환
class SavePickerDialog extends StatelessWidget {
  const SavePickerDialog({super.key, required this.saves});

  final List<SaveFileInfo> saves;

  /// 다이얼로그 표시 및 결과 반환
  static Future<String?> show(
    BuildContext context,
    List<SaveFileInfo> saves,
  ) async {
    if (saves.isEmpty) {
      // 저장 파일이 없으면 안내 메시지
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(const SnackBar(content: Text('저장된 게임이 없습니다.')));
      return null;
    }

    return showDialog<String>(
      context: context,
      builder: (context) => SavePickerDialog(saves: saves),
    );
  }

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

    return AlertDialog(
      title: Row(
        children: [
          Icon(Icons.folder_open, color: colorScheme.primary),
          const SizedBox(width: 12),
          const Text('Load Game'),
        ],
      ),
      content: SizedBox(
        width: 400,
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxHeight: 400),
          child: ListView.separated(
            shrinkWrap: true,
            itemCount: saves.length,
            separatorBuilder: (_, __) => const Divider(height: 1),
            itemBuilder: (context, index) {
              final save = saves[index];
              return _SaveListTile(
                save: save,
                onTap: () => Navigator.of(context).pop(save.fileName),
              );
            },
          ),
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(context).pop(null),
          child: const Text('Cancel'),
        ),
      ],
    );
  }
}

class _SaveListTile extends StatelessWidget {
  const _SaveListTile({required this.save, required this.onTap});

  final SaveFileInfo save;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final dateFormat = DateFormat('yyyy-MM-dd HH:mm');

    return ListTile(
      leading: const Icon(Icons.save),
      title: Text(
        save.displayName,
        style: theme.textTheme.titleMedium?.copyWith(
          fontWeight: FontWeight.w600,
        ),
      ),
      subtitle: Text(
        '${dateFormat.format(save.modifiedAt)} · ${_formatSize(save.sizeBytes)}',
        style: theme.textTheme.bodySmall,
      ),
      trailing: const Icon(Icons.chevron_right),
      onTap: onTap,
    );
  }

  String _formatSize(int bytes) {
    if (bytes < 1024) return '$bytes B';
    if (bytes < 1024 * 1024) return '${(bytes / 1024).toStringAsFixed(1)} KB';
    return '${(bytes / (1024 * 1024)).toStringAsFixed(1)} MB';
  }
}