add alot

lib/utils/app_update_util.dart

@@ -0,0 +1,242 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:crypto/crypto.dart';
+import 'package:http/http.dart' as http;
+// import 'package:open_filex/open_filex.dart';
+
+// import 'package:package_info_plus/package_info_plus.dart';
+import 'package:path_provider/path_provider.dart';
+
+
+class UpdateInfo {
+  final bool update;
+  final String version;
+  final String notes;
+  final bool mandatory;
+  final String sha256;
+  final String download;
+
+
+  UpdateInfo({
+    required this.update,
+    required this.version,
+    required this.notes,
+    required this.mandatory,
+    required this.sha256,
+    required this.download,
+  });
+
+
+  factory UpdateInfo.fromJson(Map<String, dynamic> json) {
+    return UpdateInfo(
+      update: json["update"] ?? false,
+      version: json["version"] ?? "",
+      notes: json["notes"] ?? "",
+      mandatory: json["mandatory"] ?? false,
+      sha256: json["sha256"] ?? "",
+      download: json["download"] ?? "",
+    );
+  }
+}
+
+
+class AppUpdateUtil {
+
+
+  final String serverUrl;
+
+
+  AppUpdateUtil({
+    required this.serverUrl,
+  });
+
+
+  /// Gets the installed app version
+  Future<String> currentVersion() async {
+    // final info =
+    // await PackageInfo.fromPlatform();
+
+    return "test";
+  }
+
+
+  /// Checks the update server
+  Future<UpdateInfo?> checkForUpdate() async {
+    final version =
+    await currentVersion();
+
+
+    final url = Uri.parse(
+      "$serverUrl/api/update?version=$version",
+    );
+
+
+    final response =
+    await http.get(url);
+
+
+    if (response.statusCode != 200) {
+      throw Exception(
+        "Update server unavailable",
+      );
+    }
+
+
+    final data =
+    jsonDecode(response.body);
+
+
+    if (data["update"] != true) {
+      return null;
+    }
+
+
+    return UpdateInfo.fromJson(data);
+  }
+
+
+  /// Downloads the APK
+  Future<File> downloadApk(UpdateInfo update, {
+
+    Function(double progress)? onProgress,
+
+  }) async {
+    final url =
+    update.download.startsWith("http")
+        ? update.download
+        : "$serverUrl${update.download}";
+
+
+    final request =
+    http.Request(
+      "GET",
+      Uri.parse(url),
+    );
+
+
+    final response =
+    await request.send();
+
+
+    if (response.statusCode != 200) {
+      throw Exception(
+        "APK download failed",
+      );
+    }
+
+
+    final total =
+        response.contentLength ?? 0;
+
+
+    int received = 0;
+
+
+    final directory =
+    await getTemporaryDirectory();
+
+
+    final file =
+    File(
+      "${directory.path}/update.apk",
+    );
+
+
+    final sink =
+    file.openWrite();
+
+    await for (final chunk in response.stream) {
+      sink.add(chunk);
+
+      received += chunk.length;
+
+      if (total > 0 && onProgress != null) {
+        onProgress(
+          received / total,
+        );
+      }
+    }
+
+    await sink.close();
+
+    return file;
+  }
+
+
+  /// Verifies APK checksum
+  Future<bool> verifySha256(File file,
+      String expectedHash,) async {
+    final bytes =
+    await file.readAsBytes();
+
+    final digest =
+    sha256.convert(bytes);
+
+    return digest.toString()
+        .toLowerCase()
+        ==
+        expectedHash.toLowerCase();
+  }
+
+
+  /// Opens Android APK installer
+  Future<void> installApk(File file,) async {
+    // final result =
+    // await OpenFilex.open(
+    //   file.path,
+    // );
+    //
+    //
+    // if (result.type != ResultType.done) {
+    //   throw Exception(
+    //     "Could not open APK installer",
+    //   );
+    // }
+  }
+
+
+  /// Full update flow
+  ///
+  /// Returns:
+  /// - null if no update exists
+  /// - UpdateInfo if update is available
+  ///
+  Future<UpdateInfo?> update({
+
+    Function(double progress)? onProgress,
+
+  }) async {
+    final info =
+    await checkForUpdate();
+
+    if (info == null) {
+      return null;
+    }
+
+    final apk =
+    await downloadApk(
+      info,
+      onProgress: onProgress,
+    );
+
+    final valid =
+    await verifySha256(
+      apk,
+      info.sha256,
+    );
+
+    if (!valid) {
+      throw Exception(
+        "APK checksum mismatch",
+      );
+    }
+
+    await installApk(
+      apk,
+    );
+
+    return info;
+  }
+
+}