import 'package:flutter/services.dart';

/// 安装进度事件（原生 PackageInstaller 会话回调经 EventChannel 回传）
class InstallEvent {
  /// progress / finished / failed
  final String event;

  /// event=progress 时的安装进度 0-100
  final int progress;

  /// event=finished 时是否安装成功
  final bool? success;

  /// event=failed 时的错误描述
  final String? error;

  const InstallEvent({
    required this.event,
    this.progress = 0,
    this.success,
    this.error,
  });
}

/// App 内安装 APK：原生侧 PackageInstaller 会话安装（InstallerChannel.kt）
class ApkInstaller {
  static const _method = MethodChannel('observer/installer');
  static const _progress = EventChannel('observer/installer/progress');

  /// 提交安装。返回 installing（已进入安装流程）/ permission_required
  /// （未允许「安装未知应用」，原生侧已拉起系统设置页）。
  static Future<String> install(String path) =>
      _method.invokeMethod<String>('install', {'path': path}).then(
            (v) => v ?? 'installing',
          );

  /// 安装进度流：progress(0-100) → finished(success) / failed(error)
  static Stream<InstallEvent> progress() {
    return _progress.receiveBroadcastStream().map((e) {
      final m = e as Map;
      return InstallEvent(
        event: m['event'] as String? ?? '',
        progress: (m['progress'] as num?)?.toInt() ?? 0,
        success: m['success'] as bool?,
        error: m['error'] as String?,
      );
    });
  }
}