import 'dart:io';

import 'package:device_info_plus/device_info_plus.dart';
import 'package:flutter/foundation.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:path/path.dart' as p;
import 'package:path_provider/path_provider.dart';
import 'package:sunny_mochi/core/crash/pending_crash_report.dart';
import 'package:riverpod_annotation/riverpod_annotation.dart';

part 'crash_reporter.g.dart';

/// Riverpod provider：崩溃报告在 main.dart 通过 overrideWithValue 注入。
/// 默认值为 null（正常启动时无崩溃）。
@Riverpod(keepAlive: true)
PendingCrashReport? pendingCrash(Ref ref) => null;

/// 全局崩溃日志服务（纯静态，不依赖 Riverpod / Flutter framework）。
///
/// **生命周期**：
/// 1. `preInit()`  — main() 最早期调用，异步缓存路径 + 设备信息
/// 2. `consumePending()` — 读取并删除上次崩溃文件（一次性消费）
/// 3. `installHooks()` — 在 SentrySetup.init appRunner 内调用，链式挂载钩子
///
/// **崩溃写入**：仅用 `File.writeAsStringSync(flush: true)`，绝对不能 await。
abstract class CrashReporter {
  static String? _crashFilePath;
  static String _deviceModel = 'unknown';
  static String _osVersion = 'unknown';
  static String _appVersion = 'unknown';
  static String _appBuild = '0';

  /// 步骤 1：异步预初始化（收集路径 + 设备信息）。
  static Future<void> preInit() async {
    try {
      final dir = await getApplicationDocumentsDirectory();
      _crashFilePath = p.join(dir.path, 'crash_report.json');

      final pkg = await PackageInfo.fromPlatform();
      _appVersion = pkg.version;
      _appBuild = pkg.buildNumber;

      if (kIsWeb) return;

      if (Platform.isAndroid) {
        final info = await DeviceInfoPlugin().androidInfo;
        _deviceModel = '${info.manufacturer} ${info.model}'.trim();
        _osVersion = 'Android ${info.version.release}';
      } else if (Platform.isIOS) {
        final info = await DeviceInfoPlugin().iosInfo;
        _deviceModel = info.utsname.machine;
        _osVersion = '${info.systemName} ${info.systemVersion}';
      } else {
        _deviceModel = Platform.operatingSystem;
        _osVersion = Platform.operatingSystemVersion;
      }
    } catch (_) {
      // preInit 失败不能阻断启动流程
    }
  }

  /// 步骤 2：一次性消费崩溃文件（读取 + 立即删除）。
  /// 返回 null 表示本次是正常启动。
  static PendingCrashReport? consumePending() {
    final path = _crashFilePath;
    if (path == null) return null;

    final file = File(path);
    if (!file.existsSync()) return null;

    try {
      final raw = file.readAsStringSync();
      file.deleteSync();
      return PendingCrashReport.fromRawJson(raw);
    } catch (_) {
      try {
        file.deleteSync();
      } catch (_) {}
      return null;
    }
  }

  /// 步骤 3：安装全局崩溃钩子（必须在 SentrySetup appRunner 内调用）。
  ///
  /// 采用链式挂载：先读出 Sentry 已设置的 handler，我们包一层写回，
  /// 确保 Sentry 依然能接到所有错误。
  static void installHooks() {
    final previousOnError = PlatformDispatcher.instance.onError;
    PlatformDispatcher.instance.onError = (error, stack) {
      _writeCrashSync(kind: 'dart', error: error, stackTrace: stack);
      return previousOnError?.call(error, stack) ?? false;
    };
  }

  /// 同步写入崩溃文件（crash hook 专用，不能有任何 await）。
  static void _writeCrashSync({
    required String kind,
    required Object error,
    required StackTrace stackTrace,
  }) {
    final path = _crashFilePath;
    if (path == null) return;

    try {
      final stackStr = stackTrace.toString();
      final truncated = stackStr.length > 4096
          ? '${stackStr.substring(0, 4096)}\n...(truncated)'
          : stackStr;

      final report = PendingCrashReport(
        kind: kind,
        error: error.toString(),
        stackTrace: truncated,
        occurredAt: DateTime.now().toUtc().toIso8601String(),
        deviceModel: _deviceModel,
        osVersion: _osVersion,
        appVersion: _appVersion,
        appBuild: _appBuild,
      );

      File(path).writeAsStringSync(
        report.toRawJson(),
        flush: true,
      );
    } catch (_) {
      // crash hook 内绝对不能抛出异常
    }
  }
}