From bb07000280f1a7e4f868445320a342c85d4d045b Mon Sep 17 00:00:00 2001
From: Imran Remtulla <imranr98@pm.me>
Date: Thu, 18 Jan 2024 20:45:06 -0500
Subject: [PATCH] Better partial APK hash as pseudo-version (related to #1101)

---
 lib/app_sources/html.dart        |  2 +-
 lib/providers/apps_provider.dart | 21 +++++++++++++++++++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/lib/app_sources/html.dart b/lib/app_sources/html.dart
index 106be54..7492051 100644
--- a/lib/app_sources/html.dart
+++ b/lib/app_sources/html.dart
@@ -310,7 +310,7 @@ class HTML extends AppSource {
             : rel);
     version ??= additionalSettings['supportFixedAPKURL'] != true
         ? rel.hashCode.toString()
-        : (await checkDownloadHash(rel)).toString();
+        : (await checkPartialDownloadHashDynamc(rel)).toString();
     return APKDetails(version, [rel].map((e) => MapEntry(e, e)).toList(),
         AppNames(uri.host, tr('app')));
   }
diff --git a/lib/providers/apps_provider.dart b/lib/providers/apps_provider.dart
index 38f6417..035d5c1 100644
--- a/lib/providers/apps_provider.dart
+++ b/lib/providers/apps_provider.dart
@@ -167,8 +167,25 @@ String hashListOfLists(List<List<int>> data) {
   return hash.hashCode.toString();
 }
 
-Future<String> checkDownloadHash(String url,
-    {int bytesToGrab = 1024, Map<String, String>? headers}) async {
+Future<String> checkPartialDownloadHashDynamc(String url,
+    {int startingSize = 1024,
+    int lowerLimit = 128,
+    Map<String, String>? headers}) async {
+  for (int i = startingSize; i >= lowerLimit; i -= 256) {
+    List<String> ab = await Future.wait([
+      checkPartialDownloadHash(url, i, headers: headers),
+      checkPartialDownloadHash(url, i, headers: headers)
+    ]);
+    if (ab[0] == ab[1]) {
+      print(i);
+      return ab[0];
+    }
+  }
+  throw NoVersionError();
+}
+
+Future<String> checkPartialDownloadHash(String url, int bytesToGrab,
+    {Map<String, String>? headers}) async {
   var req = Request('GET', Uri.parse(url));
   if (headers != null) {
     req.headers.addAll(headers);