/// 分享二维码对话框（P3 计划 Task 4）。
///
/// viewer 链接构造：`{VIEWER_BASE}/a/{publicToken}`（[ApiConfig.
/// viewerAlbumUrl]，VIEWER_BASE 经 --dart-define 覆盖，dev=模拟器宿主
/// 回环 5175）。QrImageView 渲染链接 + 链接文本可长按选中 + 一键复制。
///
/// 用 [Dialog] 而非 [AlertDialog]：AlertDialog 内容经 IntrinsicWidth
/// 测量，而 QrImageView 内部使用 LayoutBuilder（不支持 intrinsic 计算）
/// 会抛布局断言，普通 Dialog 无此路径。
library;

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:qr_flutter/qr_flutter.dart';

import '../core/config.dart';
import '../l10n/app_localizations.dart';

/// 观众分享二维码对话框（[publicToken] 来自相册详情）。
class ShareQrDialog extends StatelessWidget {
  const ShareQrDialog({required this.publicToken, super.key});

  final String publicToken;

  Future<void> _copy(BuildContext context, String url) async {
    await Clipboard.setData(ClipboardData(text: url));
    if (!context.mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(AppLocalizations.of(context).copiedToClipboard),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    final theme = Theme.of(context);
    final url = ApiConfig.viewerAlbumUrl(publicToken);
    return Dialog(
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              l10n.shareQrTitle,
              style: theme.textTheme.titleMedium
                  ?.copyWith(fontWeight: FontWeight.w600),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 16),
            Center(
              // 白底保证暗色主题下的扫码对比度。
              child: Container(
                color: Colors.white,
                padding: const EdgeInsets.all(8),
                child: QrImageView(
                  data: url,
                  version: QrVersions.auto,
                  size: 216,
                  backgroundColor: Colors.white,
                ),
              ),
            ),
            const SizedBox(height: 12),
            SelectableText(
              url,
              textAlign: TextAlign.center,
              style: theme.textTheme.bodySmall,
            ),
            const SizedBox(height: 8),
            Text(
              l10n.qrHint,
              textAlign: TextAlign.center,
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
            const SizedBox(height: 12),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                TextButton.icon(
                  onPressed: () => _copy(context, url),
                  icon: const Icon(Icons.copy_outlined),
                  label: Text(l10n.copyLink),
                ),
                TextButton(
                  onPressed: () => Navigator.of(context).pop(),
                  child: Text(l10n.ok),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}