import 'package:flutter/material.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:url_launcher/url_launcher.dart';

import '../services/api_client.dart';
import '../services/update_service.dart';
import '../utils/i10n.dart';

/// 全局「已弹过更新提示」标记，避免会话内重复弹窗。
bool _promptedThisSession = false;

/// 全局当前 [PackageInfo] 缓存（首次读取后复用）。
PackageInfo? _cachedPackageInfo;

/// 取得当前 App 包信息（带缓存）。
Future<PackageInfo> get currentPackageInfo async =>
    _cachedPackageInfo ??= await PackageInfo.fromPlatform();

/// 检测更新并在有新版时弹窗提示。
///
/// - [silentIfNoUpdate]=true（如启动时）：无更新或检测失败均静默；
/// - [silentIfNoUpdate]=false（如手动「检查更新」）：无更新/失败给出明确反馈。
/// - [orgId] 当前登录用户所属组织 ID；传空时与旧行为一致。
Future<void> checkAndPromptUpdate(
  BuildContext context, {
  bool silentIfNoUpdate = true,
  String? orgId,
}) async {
  final t = AppLocalizations.of(context);
  try {
    final pkg = await currentPackageInfo;
    final service = UpdateService(packageName: pkg.packageName);
    final currentCode = int.tryParse(pkg.buildNumber) ?? 0;
    final result = await service.checkForUpdate(currentCode, orgId: orgId);

    if (!context.mounted) return;

    if (result.hasUpdate && result.latest != null) {
      if (!_promptedThisSession) {
        _promptedThisSession = true;
        showUpdateDialog(context, result, pkg);
      }
      return;
    }

    if (!silentIfNoUpdate && context.mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(t.updateNoNew)),
      );
    }
  } catch (e) {
    // 任何异常均被捕获，不抛给调用方；仅非静默模式下给用户一句友好提示。
    if (!silentIfNoUpdate && context.mounted) {
      final detail = formatApiError(e, fallback: '网络异常，请稍后重试');
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('检测更新失败：$detail')),
      );
    }
  }
}

/// 版本更新提示对话框：展示当前 / 最新版本，并提供「立即更新」跳转下载。
void showUpdateDialog(
  BuildContext context,
  UpdateCheckResult result,
  PackageInfo pkg,
) {
  final t = AppLocalizations.of(context);
  final latest = result.latest!;
  showDialog<void>(
    context: context,
    builder: (ctx) => AlertDialog(
      title: Row(
        children: [
          const Icon(Icons.system_update_alt, color: Colors.green),
          const SizedBox(width: 8),
          Text(t.updateAvailable),
        ],
      ),
      content: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          _InfoRow(label: t.currentVersion, value: '${pkg.version} (${pkg.buildNumber})'),
          const SizedBox(height: 6),
          _InfoRow(
            label: t.latestVersion,
            value: '${latest.versionName} (${latest.versionCode})',
          ),
          if (latest.apkUrl.isNotEmpty) ...[
            const SizedBox(height: 6),
            _InfoRow(label: t.downloadUrl, value: latest.apkUrl),
          ],
        ],
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(ctx),
          child: Text(t.updateLater),
        ),
        FilledButton(
          onPressed: () async {
            Navigator.pop(ctx);
            final url = latest.apkUrl;
            if (url.isEmpty) return;
            final uri = Uri.parse(url);
            try {
              if (await canLaunchUrl(uri)) {
                await launchUrl(uri, mode: LaunchMode.externalApplication);
              } else if (context.mounted) {
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(content: Text(t.updateOpenFailed)),
                );
              }
            } catch (_) {
              if (context.mounted) {
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(content: Text(t.updateOpenFailed)),
                );
              }
            }
          },
          child: Text(t.updateNow),
        ),
      ],
    ),
  );
}

/// 对话框内的「标签：值」单行。
class _InfoRow extends StatelessWidget {
  const _InfoRow({required this.label, required this.value});

  final String label;
  final String value;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        SizedBox(
          width: 84,
          child: Text(
            label,
            style: theme.textTheme.bodySmall?.copyWith(
              color: theme.colorScheme.onSurfaceVariant,
            ),
          ),
        ),
        Expanded(
          child: SelectableText(
            value,
            style: theme.textTheme.bodyMedium,
          ),
        ),
      ],
    );
  }
}