Merge pull request #3209 from davotoula/fix/media-server-default-reset

Stop media-server default from resetting on every launch

amethyst/src/main/java/com/vitorpamplona/amethyst/model/nipB7Blossom/BlossomServerListState.kt

@@ -89,8 +89,8 @@ class BlossomServerListState(
             }.onStart {
                 emit(mergeServerList(flow.value))
             }.onEach { servers ->
-                if (servers.none { it == settings.defaultFileServer }) {
-                    settings.changeDefaultFileServer(servers.firstOrNull() ?: DEFAULT_MEDIA_SERVERS[0])
+                resetTargetOrNull(flow.value, servers, settings.defaultFileServer)?.let {
+                    settings.changeDefaultFileServer(it)
                 }
             }.flowOn(Dispatchers.IO)
             .stateIn(
@@ -127,3 +127,25 @@ class BlossomServerListState(
         alt: String,
     ): BlossomAuthorizationEvent = BlossomAuthorizationEvent.createDeleteAuth(hash, alt, signer)
 }
+
+/**
+ * Decides whether the persisted default file server must be reset, and to what.
+ *
+ * Returns the new default server, or `null` when no change should happen.
+ *
+ * The guard on [rawList] being non-empty is what prevents the startup race: before the user's
+ * [BlossomServersEvent] (kind 10063) loads from cache/relay, [rawList] is empty and [merged] is the
+ * transient [DEFAULT_MEDIA_SERVERS] fallback. Resetting against that fallback would clobber the
+ * locally-saved pick on every launch. Only reset once a real, loaded list is in hand and it no
+ * longer contains the current pick (e.g. the user removed it from their list).
+ */
+fun resetTargetOrNull(
+    rawList: List<String>,
+    merged: List<ServerName>,
+    current: ServerName,
+): ServerName? =
+    if (rawList.isNotEmpty() && merged.none { it == current }) {
+        merged.firstOrNull() ?: DEFAULT_MEDIA_SERVERS[0]
+    } else {
+        null
+    }

amethyst/src/test/java/com/vitorpamplona/amethyst/model/nipB7Blossom/BlossomServerListResetTest.kt

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.model.nipB7Blossom
+
+import com.vitorpamplona.amethyst.ui.actions.mediaServers.ServerName
+import com.vitorpamplona.amethyst.ui.actions.mediaServers.ServerType
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class BlossomServerListResetTest {
+    private fun server(host: String) = ServerName(host, "https://$host/", ServerType.Blossom)
+
+    private val a = server("a.example")
+    private val b = server("b.example")
+    private val c = server("c.example")
+    private val custom = server("my-custom.example")
+
+    @Test
+    fun transientDefaultEmissionDoesNotClobberSavedPick() {
+        // Regression guard: before the user's BlossomServersEvent loads, the raw
+        // published list is empty and `merged` is the DEFAULT_MEDIA_SERVERS fallback.
+        // The saved custom pick must NOT be reset.
+        val result =
+            resetTargetOrNull(
+                rawList = emptyList(),
+                merged = listOf(a, b, c),
+                current = custom,
+            )
+
+        assertNull(result)
+    }
+
+    @Test
+    fun loadedListWithoutCurrentResetsToFirst() {
+        // The user removed their current default from the published list -> reset.
+        val result =
+            resetTargetOrNull(
+                rawList = listOf("a.example", "b.example", "c.example"),
+                merged = listOf(a, b, c),
+                current = custom,
+            )
+
+        assertEquals(a, result)
+    }
+
+    @Test
+    fun loadedListContainingCurrentDoesNotReset() {
+        val result =
+            resetTargetOrNull(
+                rawList = listOf("a.example", "b.example", "c.example"),
+                merged = listOf(a, b, c),
+                current = b,
+            )
+
+        assertNull(result)
+    }
+}