From 71755763b9a50fade54de91c911e3ea086a0eb38 Mon Sep 17 00:00:00 2001
From: Imran Remtulla <imranr98@pm.me>
Date: Sat, 7 Oct 2023 13:15:22 -0400
Subject: [PATCH] Enabled WhatsApp Source (#357)

---
 lib/app_sources/whatsapp.dart      | 48 ++++++++----------------------
 lib/providers/source_provider.dart |  3 +-
 2 files changed, 15 insertions(+), 36 deletions(-)

diff --git a/lib/app_sources/whatsapp.dart b/lib/app_sources/whatsapp.dart
index f17d8a0..ff295b4 100644
--- a/lib/app_sources/whatsapp.dart
+++ b/lib/app_sources/whatsapp.dart
@@ -16,14 +16,13 @@ class WhatsApp extends AppSource {
   @override
   Future<String> apkUrlPrefetchModifier(
       String apkUrl, String standardUrl) async {
-    Response res = await sourceRequest('https://www.whatsapp.com/android');
+    Response res = await sourceRequest('$standardUrl/android');
     if (res.statusCode == 200) {
       var targetLinks = parse(res.body)
           .querySelectorAll('a')
           .map((e) => e.attributes['href'] ?? '')
           .where((e) => e.isNotEmpty)
-          .where((e) =>
-              e.contains('content.whatsapp.net') && e.contains('WhatsApp.apk'))
+          .where((e) => e.contains('WhatsApp.apk'))
           .toList();
       if (targetLinks.isEmpty) {
         throw NoAPKError();
@@ -39,37 +38,16 @@ class WhatsApp extends AppSource {
     String standardUrl,
     Map<String, dynamic> additionalSettings,
   ) async {
-    Response res = await sourceRequest('https://www.whatsapp.com/android');
-    if (res.statusCode == 200) {
-      var targetElements = parse(res.body)
-          .querySelectorAll('p')
-          .where((element) => element.innerHtml.contains('Version '))
-          .toList();
-      if (targetElements.isEmpty) {
-        throw NoVersionError();
-      }
-      var vLines = targetElements[0]
-          .innerHtml
-          .split('\n')
-          .where((element) => element.contains('Version '))
-          .toList();
-      if (vLines.isEmpty) {
-        throw NoVersionError();
-      }
-      var versionMatch = RegExp('[0-9]+(\\.[0-9]+)+').firstMatch(vLines[0]);
-      if (versionMatch == null) {
-        throw NoVersionError();
-      }
-      String version =
-          vLines[0].substring(versionMatch.start, versionMatch.end);
-      return APKDetails(
-          version,
-          getApkUrlsFromUrls([
-            'https://www.whatsapp.com/android?v=$version&=thisIsaPlaceholder&a=realURLPrefetchedAtDownloadTime'
-          ]),
-          AppNames('Meta', 'WhatsApp'));
-    } else {
-      throw getObtainiumHttpError(res);
-    }
+    // 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));
+    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'));
   }
 }
diff --git a/lib/providers/source_provider.dart b/lib/providers/source_provider.dart
index b4b732f..958f8e9 100644
--- a/lib/providers/source_provider.dart
+++ b/lib/providers/source_provider.dart
@@ -28,6 +28,7 @@ import 'package:obtainium/app_sources/steammobile.dart';
 import 'package:obtainium/app_sources/telegramapp.dart';
 import 'package:obtainium/app_sources/uptodown.dart';
 import 'package:obtainium/app_sources/vlc.dart';
+import 'package:obtainium/app_sources/whatsapp.dart';
 import 'package:obtainium/components/generated_form.dart';
 import 'package:obtainium/custom_errors.dart';
 import 'package:obtainium/mass_app_sources/githubstars.dart';
@@ -557,7 +558,7 @@ class SourceProvider {
         Mullvad(),
         Signal(),
         VLC(),
-        // WhatsApp(), // As of 2023-03-20 this is unusable as the version on the webpage is months out of date
+        WhatsApp(), // As of 2023-03-20 this is unusable as the version on the webpage is months out of date
         TelegramApp(),
         SteamMobile(),
         NeutronCode(),