Add a method to build an `OutgoingMessageEntity` from an `Envelope`

service/src/main/java/org/whispersystems/textsecuregcm/entities/OutgoingMessageEntity.java

@@ -7,13 +7,14 @@ package org.whispersystems.textsecuregcm.entities;
 
 import com.google.protobuf.ByteString;
 import org.apache.commons.lang3.StringUtils;
+import javax.annotation.Nullable;
 import java.util.Arrays;
 import java.util.Objects;
 import java.util.UUID;
 
-public record OutgoingMessageEntity(UUID guid, int type, long timestamp, String source, UUID sourceUuid,
+public record OutgoingMessageEntity(UUID guid, int type, long timestamp, @Nullable String source,
-                                    int sourceDevice, UUID destinationUuid, UUID updatedPni, byte[] content,
+                                    @Nullable UUID sourceUuid, int sourceDevice, UUID destinationUuid,
-                                    long serverTimestamp) {
+                                    @Nullable UUID updatedPni, byte[] content, long serverTimestamp) {
 
   public MessageProtos.Envelope toEnvelope() {
     final MessageProtos.Envelope.Builder builder = MessageProtos.Envelope.newBuilder()
@@ -43,6 +44,20 @@ public record OutgoingMessageEntity(UUID guid, int type, long timestamp, String
     return builder.build();
   }
 
+  public static OutgoingMessageEntity fromEnvelope(final MessageProtos.Envelope envelope) {
+    return new OutgoingMessageEntity(
+        UUID.fromString(envelope.getServerGuid()),
+        envelope.getType().getNumber(),
+        envelope.getTimestamp(),
+        envelope.getSource(),
+        envelope.hasSourceUuid() ? UUID.fromString(envelope.getSourceUuid()) : null,
+        envelope.getSourceDevice(),
+        envelope.hasDestinationUuid() ? UUID.fromString(envelope.getDestinationUuid()) : null,
+        envelope.hasUpdatedPni() ? UUID.fromString(envelope.getUpdatedPni()) : null,
+        envelope.getContent().toByteArray(),
+        envelope.getServerTimestamp());
+  }
+
   @Override
   public boolean equals(final Object o) {
     if (this == o) {

service/src/test/java/org/whispersystems/textsecuregcm/entities/OutgoingMessageEntityTest.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2013-2022 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.entities;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Random;
+import java.util.UUID;
+import java.util.stream.Stream;
+import javax.annotation.Nullable;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.whispersystems.textsecuregcm.storage.Device;
+
+class OutgoingMessageEntityTest {
+
+  @ParameterizedTest
+  @MethodSource
+  void toFromEnvelope(@Nullable final String source, @Nullable final UUID sourceUuid, @Nullable final UUID updatedPni) {
+    final byte[] messageContent = new byte[16];
+    new Random().nextBytes(messageContent);
+
+    final long messageTimestamp = System.currentTimeMillis();
+    final long serverTimestamp = messageTimestamp + 17;
+
+    final OutgoingMessageEntity outgoingMessageEntity = new OutgoingMessageEntity(UUID.randomUUID(),
+        MessageProtos.Envelope.Type.CIPHERTEXT_VALUE,
+        messageTimestamp,
+        "+18005551234",
+        UUID.randomUUID(),
+        source != null ? (int) Device.MASTER_ID : 0,
+        UUID.randomUUID(),
+        UUID.randomUUID(),
+        messageContent,
+        serverTimestamp);
+
+    assertEquals(outgoingMessageEntity, OutgoingMessageEntity.fromEnvelope(outgoingMessageEntity.toEnvelope()));
+  }
+
+  private static Stream<Arguments> toFromEnvelope() {
+    return Stream.of(
+        Arguments.of("+18005551234", UUID.randomUUID(), UUID.randomUUID()),
+        Arguments.of("+18005551234", UUID.randomUUID(), null),
+        Arguments.of(null, null, UUID.randomUUID()));
+  }
+}