From 1a7eae9471c724a33f27d6cad657028fadbd747a Mon Sep 17 00:00:00 2001
From: Gervasio Marchand <github@gervas.io>
Date: Tue, 20 Dec 2022 09:46:15 -0300
Subject: [PATCH] Avoid sending Announce to instances about their own statuses

---
 src/FakeRelay.Core/Extensions.cs             |  7 +++++++
 src/FakeRelay.Core/Helpers/MastodonHelper.cs | 11 +++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)
 create mode 100644 src/FakeRelay.Core/Extensions.cs

diff --git a/src/FakeRelay.Core/Extensions.cs b/src/FakeRelay.Core/Extensions.cs
new file mode 100644
index 0000000..fccf168
--- /dev/null
+++ b/src/FakeRelay.Core/Extensions.cs
@@ -0,0 +1,7 @@
+namespace FakeRelay.Core;
+
+public static class Extensions
+{
+    public static bool StartsWithCI(this string s, string prefix) =>
+        s.StartsWith(prefix, StringComparison.OrdinalIgnoreCase);
+}
diff --git a/src/FakeRelay.Core/Helpers/MastodonHelper.cs b/src/FakeRelay.Core/Helpers/MastodonHelper.cs
index b44262d..8618cca 100644
--- a/src/FakeRelay.Core/Helpers/MastodonHelper.cs
+++ b/src/FakeRelay.Core/Helpers/MastodonHelper.cs
@@ -4,8 +4,14 @@ namespace FakeRelay.Core.Helpers;
 
 public static class MastodonHelper
 {
-    public static Task<string> EnqueueStatusToFetchAsync(string targetHost, string statusUrl) =>
-        SendMessageToInboxAsync(targetHost, $@"{{
+    public static async Task<string> EnqueueStatusToFetchAsync(string targetHost, string statusUrl)
+    {
+        if (statusUrl.StartsWithCI($"https://{targetHost}") || statusUrl.StartsWithCI($"http://{targetHost}"))
+        {
+            return "Status ignored, it's local";
+        }
+        
+        return await SendMessageToInboxAsync(targetHost, $@"{{
     ""@context"": ""https://www.w3.org/ns/activitystreams"",
     ""actor"": ""https://{Config.Instance.Host}/actor"",
     ""id"": ""https://{Config.Instance.Host}/activities/{Guid.NewGuid()}"",
@@ -15,6 +21,7 @@ public static class MastodonHelper
     ],
     ""type"": ""Announce""
 }}");
+    }
 
     public static async Task<string> SendMessageToInboxAsync(string targetHost, string content)
     {