student-legacy/filcnaplo/lib/helpers/update_helper.dart

import 'dart:async';
import 'dart:io';
import 'dart:typed_data';

import 'package:filcnaplo/api/client.dart';
import 'package:filcnaplo/helpers/storage_helper.dart';
import 'package:filcnaplo/models/release.dart';
import 'package:open_file/open_file.dart';

enum UpdateState { prepare, downloading, installing }
typedef UpdateCallback = Function(double progress, UpdateState state);

extension UpdateHelper on Release {
  Future<void> install({UpdateCallback? updateCallback}) async {
    String downloads = await StorageHelper.downloadsPath();
    File apk = File("$downloads/filcnaplo-${version}.apk");

    if (!await apk.exists()) {
      updateCallback!(-1, UpdateState.downloading);

      var bytes = await download(updateCallback: updateCallback);
      if (!await StorageHelper.write(apk.path, bytes)) throw "failed to write apk: permission denied";
    }

    updateCallback!(-1, UpdateState.installing);

    var result = await OpenFile.open(apk.path);

    if (result.type != ResultType.done) {
      print("ERROR: installUpdate.openFile: " + result.message);
      throw result.message;
    }

    updateCallback(-1, UpdateState.prepare);
  }

  Future<Uint8List> download({UpdateCallback? updateCallback}) async {
    var response = await FilcAPI.downloadRelease(this);

    List<List<int>> chunks = [];
    int downloaded = 0;

    var completer = Completer<Uint8List>();

    response?.stream.listen((List<int> chunk) {
      updateCallback!(downloaded / (response.contentLength ?? 0), UpdateState.downloading);

      chunks.add(chunk);
      downloaded += chunk.length;
    }, onDone: () {
      // Save the file
      final Uint8List bytes = Uint8List(response.contentLength ?? 0);
      int offset = 0;
      for (List<int> chunk in chunks) {
        bytes.setRange(offset, offset + chunk.length, chunk);
        offset += chunk.length;
      }

      completer.complete(bytes);
    });

    return completer.future;
  }
}