feat: Enhance AI command processing with fallback handling and null c…

java-ecosystem/libs/analysis-engine/src/main/java/org/rostilos/codecrow/analysisengine/aiclient/AiCommandClient.java

@@ -41,9 +41,9 @@ public SummarizeResult summarize(SummarizeRequest request, Consumer<Map<String,
         Map<String, Object> finalResult = executeAsyncJob(jobId, "summarize", request, eventHandler);
 
         return new SummarizeResult(
-                (String) finalResult.getOrDefault("summary", ""),
-                (String) finalResult.getOrDefault("diagram", ""),
-                (String) finalResult.getOrDefault("diagramType", "MERMAID"));
+                stringValue(finalResult, "summary", ""),
+                stringValue(finalResult, "diagram", ""),
+                stringValue(finalResult, "diagramType", "MERMAID"));
     }
 
     /**
@@ -56,7 +56,7 @@ public AskResult ask(AskRequest request, Consumer<Map<String, Object>> eventHand
 
         Map<String, Object> finalResult = executeAsyncJob(jobId, "ask", request, eventHandler);
 
-        return new AskResult((String) finalResult.getOrDefault("answer", ""));
+        return new AskResult(stringValue(finalResult, "answer", ""));
     }
 
     /**
@@ -69,7 +69,12 @@ public ReviewResult review(ReviewRequest request, Consumer<Map<String, Object>>
 
         Map<String, Object> finalResult = executeAsyncJob(jobId, "review", request, eventHandler);
 
-        return new ReviewResult((String) finalResult.getOrDefault("review", ""));
+        return new ReviewResult(stringValue(finalResult, "review", ""));
+    }
+
+    private static String stringValue(Map<String, Object> result, String key, String defaultValue) {
+        Object value = result.get(key);
+        return value == null ? defaultValue : String.valueOf(value);
     }
 
     @SuppressWarnings("unchecked")

java-ecosystem/libs/analysis-engine/src/test/java/org/rostilos/codecrow/analysisengine/aiclient/AiCommandClientTest.java

@@ -12,6 +12,7 @@
 import org.rostilos.codecrow.queue.RedisQueueService;
 
 import java.io.IOException;
+import java.util.HashMap;
 import java.util.Map;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -101,6 +102,28 @@ void shouldThrowIOExceptionWhenErrorEvent() throws Exception {
                                         .isInstanceOf(IOException.class)
                                         .hasMessageContaining("AI service returned error: Rate limit exceeded");
                 }
+
+                @Test
+                @DisplayName("should default null summarize result fields")
+                void shouldDefaultNullSummarizeResultFields() throws Exception {
+                        Map<String, Object> resultPayload = new HashMap<>();
+                        resultPayload.put("summary", null);
+                        resultPayload.put("diagram", null);
+                        resultPayload.put("diagramType", null);
+
+                        Map<String, Object> finalEvent = new HashMap<>();
+                        finalEvent.put("type", "final");
+                        finalEvent.put("result", resultPayload);
+
+                        when(queueService.rightPop(anyString(), anyLong()))
+                                        .thenReturn(objectMapper.writeValueAsString(finalEvent));
+
+                        AiCommandClient.SummarizeResult result = client.summarize(createSummarizeRequest(), null);
+
+                        assertThat(result.summary()).isEmpty();
+                        assertThat(result.diagram()).isEmpty();
+                        assertThat(result.diagramType()).isEqualTo("MERMAID");
+                }
         }
 
         @Nested
@@ -121,6 +144,24 @@ void shouldSuccessfullyAnswerQuestion() throws Exception {
 
                         assertThat(result.answer()).isEqualTo("This code implements a REST API endpoint");
                 }
+
+                @Test
+                @DisplayName("should default null answer field")
+                void shouldDefaultNullAnswerField() throws Exception {
+                        Map<String, Object> resultPayload = new HashMap<>();
+                        resultPayload.put("answer", null);
+
+                        Map<String, Object> finalEvent = new HashMap<>();
+                        finalEvent.put("type", "final");
+                        finalEvent.put("result", resultPayload);
+
+                        when(queueService.rightPop(anyString(), anyLong()))
+                                        .thenReturn(objectMapper.writeValueAsString(finalEvent));
+
+                        AiCommandClient.AskResult result = client.ask(createAskRequest(), null);
+
+                        assertThat(result.answer()).isEmpty();
+                }
         }
 
         @Nested
@@ -141,5 +182,23 @@ void shouldSuccessfullyReviewCode() throws Exception {
 
                         assertThat(result.review()).isEqualTo("## Code Review\n\nLooks good!");
                 }
+
+                @Test
+                @DisplayName("should default null review field")
+                void shouldDefaultNullReviewField() throws Exception {
+                        Map<String, Object> resultPayload = new HashMap<>();
+                        resultPayload.put("review", null);
+
+                        Map<String, Object> finalEvent = new HashMap<>();
+                        finalEvent.put("type", "final");
+                        finalEvent.put("result", resultPayload);
+
+                        when(queueService.rightPop(anyString(), anyLong()))
+                                        .thenReturn(objectMapper.writeValueAsString(finalEvent));
+
+                        AiCommandClient.ReviewResult result = client.review(createReviewRequest(), null);
+
+                        assertThat(result.review()).isEmpty();
+                }
         }
 }

java-ecosystem/services/pipeline-agent/src/main/java/org/rostilos/codecrow/pipelineagent/generic/processor/command/AskCommandProcessor.java

@@ -297,7 +297,17 @@ private String generateAnswer(
             );
 
             log.info("AI answer generated successfully");
-            return result.answer();
+            String answer = result != null ? result.answer() : null;
+            if (!hasUsableAnswer(answer)) {
+                log.warn(
+                    "AI ask result did not include usable answer content for project={}, PR={}; using fallback answer",
+                    project.getId(),
+                    payload.pullRequestId()
+                );
+                return generatePlaceholderAnswer(question, context, contextData);
+            }
+
+            return answer;
         } catch (IOException e) {
             log.error("Failed to generate answer via AI: {}", e.getMessage(), e);
             throw new AiGenerationException("AI service failed: " + e.getMessage(), e);
@@ -462,7 +472,9 @@ private String generatePlaceholderAnswer(
                 if (!contextData.analysisInfo().isBlank()) {
                     answer.append(contextData.analysisInfo());
                 } else {
-                    answer.append("No analysis data found for this PR yet.\n");
+                    answer.append("I couldn't generate a detailed AI answer for this PR.\n\n");
+                    answer.append("No analysis data was found for this PR yet. ");
+                    answer.append("Run `/codecrow analyze` first, then retry your question.\n");
                 }
             }
             case ANALYSIS_RELATED -> {
@@ -485,7 +497,7 @@ private String generatePlaceholderAnswer(
             }
             default -> {
                 answer.append("**Answer**\n\n");
-                answer.append("_Full AI-powered answers are pending implementation._\n\n");
+                answer.append("I couldn't generate a detailed AI answer for this question.\n\n");
                 answer.append("Your question: \"").append(truncate(question, 200)).append("\"\n\n");
                 answer.append("For now, you can:\n");
                 answer.append("- Use `/codecrow analyze` to run PR analysis\n");
@@ -501,7 +513,11 @@ private String formatResponse(String answer, QuestionContext context) {
         StringBuilder sb = new StringBuilder();
         sb.append("<!-- codecrow-ask-response -->\n");
         sb.append("## 💬 CodeCrow Answer\n\n");
-        sb.append(answer);
+        if (hasUsableAnswer(answer)) {
+            sb.append(answer);
+        } else {
+            sb.append("I couldn't generate an answer. Please try rephrasing your question.");
+        }
 
         String content = sb.toString();
         if (content.length() > MAX_RESPONSE_LENGTH) {
@@ -517,6 +533,17 @@ private String truncate(String text, int maxLength) {
         return text.substring(0, maxLength) + "...";
     }
 
+    private boolean hasUsableAnswer(String answer) {
+        if (answer == null || answer.isBlank()) {
+            return false;
+        }
+
+        String normalized = answer.trim();
+        return !"No output generated".equalsIgnoreCase(normalized)
+                && !"null".equalsIgnoreCase(normalized)
+                && !"none".equalsIgnoreCase(normalized);
+    }
+
     /**
      * Types of questions that can be asked.
      */

java-ecosystem/services/pipeline-agent/src/main/java/org/rostilos/codecrow/pipelineagent/generic/processor/command/SummarizeCommandProcessor.java

@@ -217,11 +217,19 @@ private SummaryResult generateSummary(
 
             log.info("AI summarization completed successfully");
 
-            // Convert diagram type from string to enum
-            PrSummarizeCache.DiagramType resultDiagramType = 
-                "ASCII".equalsIgnoreCase(result.diagramType()) 
-                    ? PrSummarizeCache.DiagramType.ASCII 
-                    : PrSummarizeCache.DiagramType.MERMAID;
+            PrSummarizeCache.DiagramType resultDiagramType = resolveDiagramType(
+                result != null ? result.diagramType() : null,
+                diagramType
+            );
+
+            if (result == null || !hasText(result.summary())) {
+                log.warn(
+                    "AI summarize result did not include summary content for project={}, PR={}; using fallback summary",
+                    project.getId(),
+                    payload.pullRequestId()
+                );
+                return generateFallbackSummary(payload, resultDiagramType);
+            }
 
             return new SummaryResult(
                 result.summary(),
@@ -390,13 +398,13 @@ private String generatePlaceholderSummary(WebhookPayload payload, PrSummarizeCac
           .append("`.\n\n");
 
         sb.append("### Key Changes\n");
-        sb.append("_Summary generation via AI is pending implementation._\n\n");
+        sb.append("_CodeCrow could not generate a detailed AI summary from the AI response._\n\n");
 
         sb.append("### Impact Analysis\n");
-        sb.append("_Analysis pending._\n\n");
+        sb.append("_Check the job logs for the underlying AI response details._\n\n");
 
         sb.append("### Recommendations\n");
-        sb.append("_Recommendations pending._\n\n");
+        sb.append("_Review the pull request manually before merging._\n\n");
 
         return sb.toString();
     }
@@ -443,18 +451,40 @@ private PrSummarizeCache cacheResult(
             WebhookPayload payload,
             SummaryResult summaryResult
     ) {
+        String summaryContent = summaryResult != null ? summaryResult.summaryContent() : null;
+        if (!hasText(summaryContent)) {
+            throw new IllegalStateException("Cannot cache empty summary content");
+        }
+
         PrSummarizeCache cache = new PrSummarizeCache();
         cache.setProject(project);
         cache.setCommitHash(payload.commitHash());
         cache.setPrNumber(Long.parseLong(payload.pullRequestId()));
-        cache.setSummaryContent(summaryResult.summaryContent());
+        cache.setSummaryContent(summaryContent);
         cache.setDiagramContent(summaryResult.diagramContent());
         cache.setDiagramType(summaryResult.diagramType());
         cache.setExpiresAt(OffsetDateTime.now().plusHours(CACHE_TTL_HOURS));
 
         return summarizeCacheRepository.save(cache);
     }
 
+    private PrSummarizeCache.DiagramType resolveDiagramType(
+            String diagramType,
+            PrSummarizeCache.DiagramType defaultDiagramType
+    ) {
+        if ("ASCII".equalsIgnoreCase(diagramType)) {
+            return PrSummarizeCache.DiagramType.ASCII;
+        }
+        if ("MERMAID".equalsIgnoreCase(diagramType)) {
+            return PrSummarizeCache.DiagramType.MERMAID;
+        }
+        return defaultDiagramType;
+    }
+
+    private boolean hasText(String value) {
+        return value != null && !value.isBlank();
+    }
+
     private String formatSummaryForPosting(SummaryResult result, PrSummarizeCache.DiagramType diagramType) {
         StringBuilder sb = new StringBuilder();
         sb.append("<!-- codecrow-summary -->\n\n");