Add "refresh before download" + remove WhatsApp (#1943)

lib/app_sources/html.dart

@@ -7,6 +7,9 @@ import 'package:obtainium/providers/apps_provider.dart';
 import 'package:obtainium/providers/source_provider.dart';
 
 String ensureAbsoluteUrl(String ambiguousUrl, Uri referenceAbsoluteUrl) {
+  if (ambiguousUrl.startsWith('//')) {
+    ambiguousUrl = '${referenceAbsoluteUrl.scheme}:$ambiguousUrl';
+  }
   try {
     Uri.parse(ambiguousUrl).origin;
     return ambiguousUrl;

lib/app_sources/whatsapp.dart

@@ -1,55 +0,0 @@
-import 'package:html/parser.dart';
-import 'package:http/http.dart';
-import 'package:obtainium/custom_errors.dart';
-import 'package:obtainium/providers/source_provider.dart';
-
-class WhatsApp extends AppSource {
-  WhatsApp() {
-    hosts = ['whatsapp.com'];
-    versionDetectionDisallowed = true;
-  }
-
-  @override
-  String sourceSpecificStandardizeURL(String url, {bool forSelection = false}) {
-    return 'https://${hosts[0]}';
-  }
-
-  @override
-  Future<String> apkUrlPrefetchModifier(String apkUrl, String standardUrl,
-      Map<String, dynamic> additionalSettings) async {
-    Response res =
-        await sourceRequest('$standardUrl/android', additionalSettings);
-    if (res.statusCode == 200) {
-      var targetLinks = parse(res.body)
-          .querySelectorAll('a')
-          .map((e) => e.attributes['href'] ?? '')
-          .where((e) => e.isNotEmpty)
-          .where((e) => e.contains('WhatsApp.apk'))
-          .toList();
-      if (targetLinks.isEmpty) {
-        throw NoAPKError();
-      }
-      return targetLinks[0];
-    } else {
-      throw getObtainiumHttpError(res);
-    }
-  }
-
-  @override
-  Future<APKDetails> getLatestAPKDetails(
-    String standardUrl,
-    Map<String, dynamic> additionalSettings,
-  ) async {
-    // This is a CDN link that is consistent per version
-    // But it has query params that change constantly
-    Uri apkUri = Uri.parse(await apkUrlPrefetchModifier(
-        standardUrl, standardUrl, additionalSettings));
-    var unusableApkUrl = '${apkUri.origin}/${apkUri.path}';
-    // So we use the param-less URL is a pseudo-version to add the app and check for updates
-    // See #357 for why we can't scrape the version number directly
-    // But we re-fetch the URL again with its latest query params at the actual download time
-    String version = unusableApkUrl.hashCode.toString();
-    return APKDetails(version, getApkUrlsFromUrls([unusableApkUrl]),
-        AppNames('Meta', 'WhatsApp'));
-  }
-}