Fix Gemini blocked content handling and improve MongoDB status endpoint

- Add explicit finish_reason checking for blocked content (17) and safety blocks (2)
- Add generation_config to request image/png response explicitly
- Better error messages for blocked content
- Improve /mongo-status endpoint to show recent 5 logs with full details
- This will help diagnose both Gemini API issues and verify MongoDB storage

api/main.py

@@ -491,9 +491,27 @@ def mongo_status(_: None = Depends(bearer_auth)) -> Dict[str, object]:
         try:
             count = mongo_logs.count_documents({})
             status["api_logs_count"] = count
-            # Get latest document
-            latest = mongo_logs.find_one(sort=[("timestamp", -1)])
-            if latest:
+            # Get latest 5 documents
+            latest_docs = list(mongo_logs.find().sort("timestamp", -1).limit(5))
+            status["recent_logs"] = []
+            for doc in latest_docs:
+                doc_dict = {
+                    "_id": str(doc.get("_id")),
+                    "output_id": doc.get("output_id"),
+                    "status": doc.get("status"),
+                    "timestamp": doc.get("timestamp").isoformat() if isinstance(doc.get("timestamp"), datetime) else str(doc.get("timestamp")),
+                }
+                if "input_image_id" in doc:
+                    doc_dict["input_image_id"] = doc.get("input_image_id")
+                if "input_mask_id" in doc:
+                    doc_dict["input_mask_id"] = doc.get("input_mask_id")
+                if "error" in doc:
+                    doc_dict["error"] = doc.get("error")
+                status["recent_logs"].append(doc_dict)
+            
+            # Get latest document for backward compatibility
+            if latest_docs:
+                latest = latest_docs[0]
                 status["latest_log"] = {
                     "_id": str(latest.get("_id")),
                     "output_id": latest.get("output_id"),
@@ -502,6 +520,7 @@ def mongo_status(_: None = Depends(bearer_auth)) -> Dict[str, object]:
                 }
         except Exception as err:
             status["api_logs_error"] = str(err)
+            log.error("Error querying MongoDB: %s", err, exc_info=True)
     
     return status
 

src/core.py

@@ -163,21 +163,46 @@ def _call_gemini_edit(
         {"mime_type": "image/png", "data": mask_bytes},
     ]
 
-    response = model.generate_content(content, stream=False)
+    # Request image response explicitly
+    generation_config = {
+        "response_mime_type": "image/png",
+    }
+    
+    try:
+        response = model.generate_content(
+            content,
+            generation_config=generation_config,
+            stream=False
+        )
+    except Exception as gen_err:
+        log.error("Gemini generate_content raised exception: %s", gen_err, exc_info=True)
+        raise RuntimeError(f"Gemini API error: {gen_err}")
 
     output_img: Image.Image | None = None
 
-    # Debug: log response structure
-    log.debug("Gemini response type: %s", type(response))
-    log.debug("Gemini response has candidates: %s", hasattr(response, "candidates"))
+    # Check for blocked content or errors
+    candidates = getattr(response, "candidates", [])
+    if not candidates:
+        log.error("Gemini returned no candidates")
+        raise RuntimeError("Gemini API returned no candidates. The request may have been blocked.")
+    
+    # Check finish_reason for blocked content
+    for idx, candidate in enumerate(candidates):
+        finish_reason = getattr(candidate, "finish_reason", None)
+        if finish_reason:
+            # finish_reason values: 0=STOP, 1=MAX_TOKENS, 2=SAFETY, 3=RECITATION, 4=OTHER, 17=BLOCKED
+            if finish_reason == 17 or finish_reason == 2:
+                safety_ratings = getattr(candidate, "safety_ratings", [])
+                log.error("Gemini blocked the request. Finish reason: %s, Safety ratings: %s", finish_reason, safety_ratings)
+                raise RuntimeError(f"Gemini API blocked the content (finish_reason={finish_reason}). The image may violate safety policies.")
+            elif finish_reason != 0:  # 0 = STOP (normal completion)
+                log.warning("Gemini finished with non-zero reason: %s", finish_reason)
     
     # Extract first image from response parts
     try:
-        candidates = getattr(response, "candidates", [])
         log.debug("Number of candidates: %d", len(candidates))
         
         for idx, candidate in enumerate(candidates):
-            log.debug("Candidate %d type: %s", idx, type(candidate))
             parts = getattr(candidate, "content", None)
             if not parts:
                 log.debug("Candidate %d has no content", idx)
@@ -189,7 +214,6 @@ def _call_gemini_edit(
             log.debug("Candidate %d has %d parts", idx, len(response_parts))
             
             for part_idx, part in enumerate(response_parts):
-                log.debug("Part %d type: %s", part_idx, type(part))
                 inline = getattr(part, "inline_data", None)
                 if inline:
                     log.debug("Part %d has inline_data, mime_type: %s", part_idx, getattr(inline, "mime_type", None))
@@ -214,11 +238,15 @@ def _call_gemini_edit(
         # Log full response for debugging
         try:
             response_text = str(response)
-            log.error("Gemini generate_content returned no image. Full response (first 500 chars): %s", response_text[:500])
+            log.error("Gemini generate_content returned no image. Full response (first 1000 chars): %s", response_text[:1000])
             # Try to extract any error messages
             if hasattr(response, "prompt_feedback"):
                 feedback = response.prompt_feedback
                 log.error("Prompt feedback: %s", feedback)
+            # Check candidates for finish reasons
+            for idx, candidate in enumerate(candidates):
+                finish_reason = getattr(candidate, "finish_reason", None)
+                log.error("Candidate %d finish_reason: %s", idx, finish_reason)
         except Exception:
             pass
         raise RuntimeError("Gemini generate_content returned no image. Check logs for details.")