android: avoid staging raw media bytes

android/app/src/androidTest/java/com/pika/app/ui/screens/ChatScreenMediaStagingTest.kt

@@ -0,0 +1,31 @@
+package com.pika.app.ui.screens
+
+import android.net.Uri
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ChatScreenMediaStagingTest {
+    @Test
+    /** Verifies that only the remaining attachment slots are accepted for staging. */
+    fun selectUrisForStaging_respectsRemainingCapacity() {
+        val uris = (1..5).map { Uri.parse("content://staging/$it") }
+
+        val accepted = selectUrisForStaging(existingCount = 30, uris = uris)
+
+        assertEquals(listOf(uris[0], uris[1]), accepted)
+    }
+
+    @Test
+    /** Verifies that no URIs are accepted once the staging cap has already been reached. */
+    fun selectUrisForStaging_returnsEmptyWhenAlreadyFull() {
+        val uris = listOf(Uri.parse("content://staging/1"))
+
+        val accepted = selectUrisForStaging(existingCount = MAX_STAGED_MEDIA_ITEMS, uris = uris)
+
+        assertTrue(accepted.isEmpty())
+    }
+}