import 'package:dio/dio.dart';
import 'package:flutter/services.dart';
import 'package:path_provider/path_provider.dart';

/// Bridges to MainActivity.kt's MethodChannel for the Android
/// PackageInstaller intent (#397). Web / iOS don't support self-
/// install; this class is Android-only at v1.
class UpdateInstaller {
  UpdateInstaller(this._dio);
  final Dio _dio;

  static const _channel = MethodChannel('com.fabledsword.minstrel/installer');
  static const _filename = 'minstrel-update.apk';

  /// Streams the APK from `apkUrl` into the cache directory. `onProgress`
  /// receives 0..1 fractions; emits 1.0 once when the download completes.
  /// Returns the local path the install intent will read from.
  Future<String> download(
    String apkUrl, {
    void Function(double progress)? onProgress,
  }) async {
    final cacheDir = await getApplicationCacheDirectory();
    final path = '${cacheDir.path}/$_filename';
    await _dio.download(
      apkUrl,
      path,
      onReceiveProgress: (received, total) {
        if (total > 0 && onProgress != null) {
          onProgress(received / total);
        }
      },
    );
    return path;
  }

  /// Hands the downloaded APK to Android's PackageInstaller via a
  /// FileProvider content:// URI. The system shows the install confirm
  /// dialog; user must tap Install. App restarts on the new version.
  ///
  /// First-ever install attempt prompts the user to flip "Install
  /// unknown apps" for Minstrel in Settings → Apps → Special access.
  /// One-time grant; persists across updates.
  Future<void> install(String apkPath) async {
    await _channel.invokeMethod('install', {'path': apkPath});
  }
}