fix: report agent-configs usage count excluding null entries (AIC-2663)

The $ld:ai:usage:agent-configs metric was reported with the full request
list size before the loop, while null entries are skipped during
evaluation. This could make the reported usage value/count exceed the
number of configs actually retrieved. Count only the non-null requests
that are evaluated and report the metric after the loop.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ctawiah

lib/sdk/server-ai/src/main/java/com/launchdarkly/sdk/server/ai/LDAIClientImpl.java

@@ -111,20 +111,21 @@ public AIAgentConfig agentConfig(
   @Override
   public Map<String, AIAgentConfig> agentConfigs(
       List<AIAgentConfigRequest> agentConfigs, LDContext context) {
-    int count = agentConfigs == null ? 0 : agentConfigs.size();
-    client.trackMetric(TRACK_USAGE_AGENT_CONFIGS, context, LDValue.of(count), count);
-
     Map<String, AIAgentConfig> result = new LinkedHashMap<>();
+    int count = 0;
     if (agentConfigs != null) {
       for (AIAgentConfigRequest request : agentConfigs) {
         if (request == null) {
           continue;
         }
+        count++;
         result.put(
             request.getKey(),
             evaluateAgent(request.getKey(), context, request.getDefaultValue(), request.getVariables()));
       }
     }
+    client.trackMetric(TRACK_USAGE_AGENT_CONFIGS, context, LDValue.of(count), count);
+
     return result;
   }
 

lib/sdk/server-ai/src/test/java/com/launchdarkly/sdk/server/ai/LDAIClientImplTest.java

@@ -2,6 +2,7 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.hasSize;
@@ -275,6 +276,19 @@ public void agentConfigsHandlesEmptyList() {
     verify(client).trackMetric(eq("$ld:ai:usage:agent-configs"), eq(context), eq(LDValue.of(0)), eq(0.0));
   }
 
+  @Test
+  public void agentConfigsUsageCountExcludesNullEntries() {
+    when(client.jsonValueVariation(anyString(), any(), any())).thenReturn(LDValue.ofNull());
+    List<AIAgentConfigRequest> requests = Arrays.asList(
+        AIAgentConfigRequest.builder("a").build(),
+        null,
+        AIAgentConfigRequest.builder("b").build());
+    Map<String, AIAgentConfig> agents = ai.agentConfigs(requests, context);
+
+    assertThat(agents.keySet(), containsInAnyOrder("a", "b"));
+    verify(client).trackMetric(eq("$ld:ai:usage:agent-configs"), eq(context), eq(LDValue.of(2)), eq(2.0));
+  }
+
   private static Map<String, Object> variables() {
     return new HashMap<>();
   }