import 'dart:convert';
import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:path_provider/path_provider.dart';

import '../api/oa_client.dart';
import '../app_runtime.dart';
import '../theme.dart';

class AppRelease {
  AppRelease({
    required this.version,
    required this.build,
    required this.url,
    this.changelog = '',
    this.force = false,
    this.windowsUrl = '',
    this.linuxUrl = '',
    this.linuxDebUrl = '',
  });
  final String version;
  final int build;
  final String url;
  final String changelog;
  final bool force;
  final String windowsUrl;
  final String linuxUrl;
  final String linuxDebUrl;

  bool get newer => build > AppRuntime.build;

  String get desktopUrl {
    if (Platform.isWindows) return windowsUrl;
    if (Platform.isLinux) return linuxDebUrl.isNotEmpty ? linuxDebUrl : linuxUrl;
    return '';
  }

  factory AppRelease.fromJson(Map<String, dynamic> j) {
    return AppRelease(
      version: '${j['version'] ?? ''}',
      build: (j['build'] as num?)?.toInt() ?? 0,
      url: '${j['url'] ?? j['apkUrl'] ?? ''}',
      changelog: '${j['changelog'] ?? ''}',
      force: j['force'] == true,
      windowsUrl: '${j['windowsUrl'] ?? ''}',
      linuxUrl: '${j['linuxUrl'] ?? ''}',
      linuxDebUrl: '${j['linuxDebUrl'] ?? ''}',
    );
  }
}

class OtaUpdater {
  OtaUpdater(this.api);
  final OaClient api;
  static const _ch = MethodChannel('com.fysxkj.oa/ota');

  Future<AppRelease?> fetch() async {
    try {
      final data = await api.get('/system/app-release');
      if (data is Map) return AppRelease.fromJson(Map<String, dynamic>.from(data));
    } catch (_) {}
    return null;
  }

  Future<void> installApk(String path) async {
    await _ch.invokeMethod('installApk', {'path': path});
  }

  Future<File> download(String url, void Function(double p) onProgress, {String filename = 'fengying-oa-update'}) async {
    final dir = await getTemporaryDirectory();
    final ext = url.contains('.exe')
        ? '.exe'
        : url.contains('.deb')
            ? '.deb'
            : url.contains('.tar.gz')
                ? '.tar.gz'
                : url.contains('.apk')
                    ? '.apk'
                    : '';
    final file = File('${dir.path}/$filename$ext');
    final client = HttpClient();
    try {
      final req = await client.getUrl(Uri.parse(url));
      final res = await req.close();
      if (res.statusCode >= 400) {
        throw ApiException('下载失败 ${res.statusCode}');
      }
      final total = res.contentLength;
      var rec = 0;
      final sink = file.openWrite();
      await for (final chunk in res) {
        rec += chunk.length;
        sink.add(chunk);
        if (total > 0) onProgress(rec / total);
      }
      await sink.close();
      return file;
    } finally {
      client.close(force: true);
    }
  }

  Future<void> prompt(BuildContext context, AppRelease rel, {bool manual = false}) async {
    if (!rel.newer && !manual) return;
    if (!rel.newer && manual) {
      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('已是最新版本')));
      }
      return;
    }
    if (!context.mounted) return;
    final go = await showDialog<bool>(
      context: context,
      barrierDismissible: !rel.force,
      builder: (ctx) => AlertDialog(
        title: Text('发现新版本 ${rel.version}'),
        content: Text(rel.changelog.isEmpty ? '请升级后继续使用。' : rel.changelog),
        actions: [
          if (!rel.force) TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('稍后')),
          FilledButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('立即升级')),
        ],
      ),
    );
    if (go == true && context.mounted) await start(context, rel);
  }

  Future<void> start(BuildContext context, AppRelease rel) async {
    final desktop = rel.desktopUrl;
    if (Platform.isWindows || Platform.isLinux) {
      if (desktop.isEmpty) {
        if (context.mounted) {
          ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('暂无桌面端升级包地址')));
        }
        return;
      }
      final progress = ValueNotifier<double>(0);
      if (!context.mounted) return;
      showDialog<void>(
        context: context,
        barrierDismissible: false,
        builder: (ctx) => AlertDialog(
          title: const Text('正在下载更新'),
          content: OtaProgress(progress: progress),
        ),
      );
      try {
        final file = await download(desktop, (p) => progress.value = p, filename: 'fengying-oa-setup');
        if (context.mounted) Navigator.of(context, rootNavigator: true).pop();
        if (Platform.isWindows) {
          await Process.start(file.path, ['/VERYSILENT', '/SUPPRESSMSGBOXES', '/NORESTART'], mode: ProcessStartMode.detached);
          if (context.mounted) {
            ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('安装程序已启动，请按提示完成升级后重启应用')));
          }
        } else if (file.path.endsWith('.deb')) {
          final r = await Process.run('pkexec', ['env', 'DEBIAN_FRONTEND=noninteractive', 'dpkg', '-i', file.path]);
          if (context.mounted) {
            if (r.exitCode == 0) {
              ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('升级完成，请重启应用')));
            } else {
              ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('安装失败：${r.stderr}')));
            }
          }
        } else {
          await Process.run('xdg-open', [file.parent.path]);
          if (context.mounted) {
            ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('已下载到 ${file.path}，请解压覆盖后重启应用')));
          }
        }
      } catch (e) {
        if (context.mounted) {
          Navigator.of(context, rootNavigator: true).pop();
          ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('升级失败：$e')));
        }
      } finally {
        progress.dispose();
      }
      return;
    }
    if (!Platform.isAndroid) return;
    if (rel.url.isEmpty) return;
    final progress = ValueNotifier<double>(0);
    if (!context.mounted) return;
    showDialog<void>(
      context: context,
      barrierDismissible: false,
      builder: (ctx) => AlertDialog(
        title: const Text('正在下载更新'),
        content: OtaProgress(progress: progress),
      ),
    );
    try {
      final file = await download(rel.url, (p) => progress.value = p);
      if (context.mounted) Navigator.of(context, rootNavigator: true).pop();
      await installApk(file.path);
    } catch (e) {
      if (context.mounted) {
        Navigator.of(context, rootNavigator: true).pop();
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('升级失败：$e')));
      }
    } finally {
      progress.dispose();
    }
  }
}

class OtaProgress extends StatefulWidget {
  const OtaProgress({super.key, required this.progress});
  final ValueListenable<double> progress;
  @override
  State<OtaProgress> createState() => _OtaProgressState();
}

class _OtaProgressState extends State<OtaProgress> {
  @override
  void initState() {
    super.initState();
    widget.progress.addListener(_on);
  }

  void _on() => setState(() {});

  @override
  void dispose() {
    widget.progress.removeListener(_on);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final p = widget.progress.value;
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        LinearProgressIndicator(value: p <= 0 ? null : p, color: kBind),
        const SizedBox(height: 12),
        Text('${(p * 100).clamp(0, 100).toStringAsFixed(0)}%'),
      ],
    );
  }
}

String prettyJson(Object v) {
  try {
    return const JsonEncoder.withIndent('  ').convert(v);
  } catch (_) {
    return '$v';
  }
}