feat: enhance logging and error handling in backend and editor components

backend/main.py

@@ -3,9 +3,12 @@ from fastapi.responses import StreamingResponse
 from pydantic import BaseModel
 import os
 import json
+import time
 
 app = FastAPI()
 
+print("[Main] Backend service starting...")
+
 class CompletionRequest(BaseModel):
     prefix: str
     suffix: str
@@ -15,33 +18,58 @@ def generate_stream(request: CompletionRequest):
     from prompt import build_prompt
     from llm import stream_openai
     
-    print(f"[Backend] Received request - prefix length: {len(request.prefix)}, suffix length: {len(request.suffix)}")
+    start_time = time.time()
+    print(f"[Main] ========== New Request ==========")
+    print(f"[Main] prefix length: {len(request.prefix)}, suffix length: {len(request.suffix)}")
+    print(f"[Main] languageId: {request.languageId}")
+    print(f"[Main] Prefix (last 200 chars): '{request.prefix[-200:]}'")
+    print(f"[Main] Suffix (first 200 chars): '{request.suffix[:200]}'")
     
     try:
         prompt = build_prompt(request.prefix, request.suffix)
-        print(f"[Backend] Built prompt (first 100 chars): {prompt[:100]}...")
+        print(f"[Main] Built prompt length: {len(prompt)}")
+        print(f"[Main] Prompt (first 300 chars): '{prompt[:300]}'")
+        print(f"[Main] Prompt (last 200 chars): '{prompt[-200:]}'")
         
         async def gen():
             chunk_count = 0
-            async for chunk in stream_openai(prompt):
-                chunk_count += 1
-                yield f"data: {chunk}\n\n"
-                if chunk_count % 5 == 0:
-                    print(f"[Backend] Sent chunk {chunk_count}")
-            yield "data: {\"done\": true}\n\n"
-            print(f"[Backend] Stream complete, total chunks: {chunk_count}")
+            first_chunk_time = None
+            try:
+                async for chunk in stream_openai(prompt):
+                    current_time = time.time()
+                    if first_chunk_time is None:
+                        first_chunk_time = current_time - start_time
+                    chunk_count += 1
+                    chunk_data = json.loads(chunk) if isinstance(chunk, str) else chunk
+                    content_preview = chunk_data.get('content', '')[:50] if chunk_data.get('content') else ''
+                    print(f"[Main] Chunk {chunk_count}: '{content_preview}'...")
+                    yield f"data: {json.dumps(chunk_data)}\n\n"
+                
+                done_signal = {"done": True}
+                total_time = time.time() - start_time
+                print(f"[Main] Stream complete - total chunks: {chunk_count}, first chunk at: {first_chunk_time:.2f}s, total time: {total_time:.2f}s")
+                yield f"data: {json.dumps(done_signal)}\n\n"
+            except Exception as e:
+                error_msg = {"error": str(e), "type": type(e).__name__}
+                print(f"[Main] Generator error: {e}")
+                yield f"data: {json.dumps(error_msg)}\n\n"
         return gen()
     except Exception as e:
-        error_msg = f"{{\"error\": \"{str(e)}\"}}"
-        print(f"[Backend] Error: {e}")
-        yield f"data: {error_msg}\n\n"
+        error_msg = {"error": str(e), "type": type(e).__name__}
+        print(f"[Main] Error building prompt or calling LLM: {e}")
+        yield f"data: {json.dumps(error_msg)}\n\n"
 
 @app.post("/v1/completions")
 async def create_completion(request: CompletionRequest):
-    print(f"[Backend] POST /v1/completions called")
+    print(f"[Main] POST /v1/completions called at {time.time()}")
     return StreamingResponse(generate_stream(request), media_type="text/event-stream")
 
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy", "timestamp": time.time()}
+
 if __name__ == "__main__":
     import uvicorn
-    print("[Backend] Starting server on http://0.0.0.0:8000")
-    uvicorn.run(app, host="0.0.0.0", port=8000)
+    port = int(os.getenv('PORT', 8000))
+    print(f"[Main] Starting server on http://0.0.0.0:{port}")
+    uvicorn.run(app, host="0.0.0.0", port=port)