Resend mismatched completed client text (#8697)

src/main/scala/net/eagle0/eagle/service/controller/HumanPlayerClientConnectionState.scala

@@ -128,7 +128,14 @@ object HumanPlayerClientConnectionState {
           // attempt is already at least as long: equal lengths do not imply equal prefixes.
           StreamingTextDiff(newText = text, startingByteCount = 0)
 
-        case status => StreamingTextDiff(newText = "", startingByteCount = status.knownByteCount)
+        case status =>
+          val serverByteCount = text.getBytes(StandardCharsets.UTF_8).length
+          if status.knownByteCount == serverByteCount then
+            StreamingTextDiff(newText = "", startingByteCount = status.knownByteCount)
+          else
+            // A legacy client can persist an empty or stale value as complete. Replace it from byte zero when the
+            // authoritative completed payload has a different length.
+            StreamingTextDiff(newText = text, startingByteCount = 0)
       }
       .getOrElse(StreamingTextDiff(newText = text, startingByteCount = 0))
 }

src/test/scala/net/eagle0/eagle/service/HumanPlayerClientConnectionStateTest.scala

@@ -1,6 +1,7 @@
 package net.eagle0.eagle.service
 
 import java.io.PrintWriter
+import java.nio.charset.StandardCharsets
 
 import net.eagle0.eagle.api.command.AvailableCommands
 import net.eagle0.eagle.api.eagle.{GameUpdate, ShardokServerStatus, UpdateStreamResponse}
@@ -488,6 +489,47 @@ class HumanPlayerClientConnectionStateTest
     }
   }
 
+  it should "replace completed client text when its known byte count differs from the server text" in {
+    val requestId    = "chronicle"
+    val text         = "Tomlin’s completed backstory"
+    val client       = new HumanPlayerClientConnectionState(
+      eagleGameId = eagleGameId,
+      factionId = fid,
+      clientId = "test-client",
+      grpcObserver = mockObserver,
+      unfilteredKnownHistoryCount = largerCount,
+      knownShardokResultCounts = Vector.empty,
+      streamingTextStatusMap = Map(
+        requestId -> StreamingTextStatus(
+          llmIdentifier = requestId,
+          knownByteCount = 0,
+          knownComplete = true
+        )
+      ),
+      logWriter = mockLogWriter
+    )
+    var sentResponse = Option.empty[UpdateStreamResponse]
+    mockObserver.onNext
+      .expects(*)
+      .onCall { (response: UpdateStreamResponse) =>
+        sentResponse = Some(response)
+      }: Unit
+
+    val updatedClient = client.update(CompleteClientText(requestId, text, 1))
+
+    updatedClient.streamingTextStatusMap(requestId).knownByteCount shouldBe text.getBytes(StandardCharsets.UTF_8).length
+    val gameUpdate = sentResponse
+      .flatMap(_.responseDetails.gameUpdate)
+      .getOrElse(fail("expected a game update"))
+    gameUpdate.gameUpdateDetails match {
+      case GameUpdate.GameUpdateDetails.StreamingTextResponse(streamingText) =>
+        streamingText.newText.shouldBe(text)
+        streamingText.startingByteCount.shouldBe(0)
+        streamingText.completed.shouldBe(true)
+      case _ => fail("expected replacement streaming text")
+    }
+  }
+
   it should "replace an old attempt even when the retry is already longer" in {
     val requestId    = "chronicle"
     val oldAttempt   = "gemini-old"