import 'dart:io';

import 'package:flutter/material.dart';

import '../../data/models/app_update_model.dart';
import '../../services/update_service.dart';
import 'toast_helper.dart';

class UpdatePrompt extends StatefulWidget {
  final Widget child;

  const UpdatePrompt({super.key, required this.child});

  @override
  State<UpdatePrompt> createState() => _UpdatePromptState();
}

class _UpdatePromptState extends State<UpdatePrompt> {
  static bool _checkedThisRun = false;
  bool _dialogVisible = false;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _checkUpdate());
  }

  Future<void> _checkUpdate() async {
    if (_checkedThisRun || _dialogVisible || !mounted) return;
    _checkedThisRun = true;

    final update = await UpdateService.instance.checkForUpdate();
    if (update == null || !mounted) return;

    _dialogVisible = true;
    try {
      await _showUpdateDialog(update);
    } finally {
      _dialogVisible = false;
    }
  }

  Future<void> _showUpdateDialog(AppUpdateInfo update) async {
    var downloading = false;
    var progress = 0.0;
    String? status;

    await showDialog<void>(
      context: context,
      barrierDismissible: false,
      builder: (dialogContext) {
        return StatefulBuilder(
          builder: (context, setDialogState) {
            final canDownload =
                update.downloadUrl != null &&
                (Platform.isAndroid || Platform.isWindows);

            Future<void> startUpdate() async {
              if (downloading || !canDownload) return;

              setDialogState(() {
                downloading = true;
                progress = 0;
                status = '正在下载更新...';
              });

              try {
                final file = await UpdateService.instance.downloadUpdate(
                  update,
                  onProgress: (received, total) {
                    if (!mounted || total <= 0) return;
                    setDialogState(() {
                      progress = received / total;
                    });
                  },
                );
                if (file == null) return;

                setDialogState(() {
                  progress = 1;
                  status = '下载完成，正在打开安装包...';
                });
                await UpdateService.instance.openInstaller(file);
                if (dialogContext.mounted) Navigator.of(dialogContext).pop();
              } catch (e) {
                setDialogState(() {
                  downloading = false;
                  status = '下载或打开安装包失败';
                });
                ToastHelper.failure('更新失败: $e');
              }
            }

            return AlertDialog(
              title: Text('发现新版本 ${update.version}'),
              content: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 420),
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(update.title),
                    if ((update.description ?? '').isNotEmpty) ...[
                      const SizedBox(height: 12),
                      Text(
                        update.description!,
                        maxLines: 6,
                        overflow: TextOverflow.ellipsis,
                      ),
                    ],
                    if (downloading) ...[
                      const SizedBox(height: 16),
                      LinearProgressIndicator(
                        value: progress == 0 ? null : progress,
                      ),
                      const SizedBox(height: 8),
                      Text(status ?? ''),
                    ],
                  ],
                ),
              ),
              actions: [
                TextButton(
                  onPressed: downloading
                      ? null
                      : () => Navigator.of(dialogContext).pop(),
                  child: const Text('稍后'),
                ),
                FilledButton(
                  onPressed: downloading ? null : startUpdate,
                  child: const Text('立即更新'),
                ),
              ],
            );
          },
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) => widget.child;
}