fix: make inference.py crash-proof when OPENAI_API_KEY is missing (Phase 2)

inference.py

@@ -1,31 +1,55 @@
 import os
 import time
-from openai import OpenAI
+
 from server.env import CodeArenaEnv
 from server.models import CodeArenaAction
 
+# ── Fallback response (always valid JSON shape) ───────────────────────────
+_FALLBACK = {
+    "action": "analyze_code",
+    "explanation": "Fallback mode: running without external API.",
+}
+
+
 def run_inference():
-    print("[START] Initializing CodeArena inference logging")
-    
-    client = OpenAI(
-        # Uses OPENAI_API_KEY from environment by default
-        # You can substitute this with any compatible endpoint
-    )
-    env = CodeArenaEnv()
-    obs = env.reset()
-    
-    system_prompt = """You are an expert autonomous code repair agent.
+    """Run the RL inference loop.  Never raises — returns valid JSON always."""
+    try:
+        print("[START] Initializing CodeArena inference logging")
+
+        api_key = os.getenv("OPENAI_API_KEY")
+
+        # Only import & initialise OpenAI when a key is available
+        if api_key:
+            try:
+                from openai import OpenAI
+                client = OpenAI(api_key=api_key)
+            except Exception as e:
+                print(f"[WARN] Could not initialise OpenAI client: {e}")
+                client = None
+        else:
+            print("[INFO] OPENAI_API_KEY not set — running in fallback mode")
+            client = None
+
+        env = CodeArenaEnv()
+        obs = env.reset()
+
+        # If no usable client, return the fallback immediately
+        if client is None:
+            print("[END] No API client available. Returning fallback response.")
+            return _FALLBACK
+
+        system_prompt = """You are an expert autonomous code repair agent.
 Your goal is to fix the buggy code provided to you.
 Ensure your code is highly efficient and fully resolves all logical, syntax, and algorithmic bugs.
 Only return the fixed raw Python code. Do not output markdown blocks (like ```python). Do not explain your changes."""
 
-    done = False
-    step = 0
-    
-    while not done and step < env.max_steps:
-        print(f"[STEP] Beginning Step {step + 1}")
-        
-        user_prompt = f"""
+        done = False
+        step = 0
+
+        while not done and step < env.max_steps:
+            print(f"[STEP] Beginning Step {step + 1}")
+
+            user_prompt = f"""
 Buggy Code:
 {obs.buggy_code}
 
@@ -35,34 +59,53 @@ Error Log:
 Test Results:
 {obs.test_results}
 """
-        try:
-            response = client.chat.completions.create(
-                model="gpt-4o", # Replace with desired model
-                messages=[
-                    {"role": "system", "content": system_prompt},
-                    {"role": "user", "content": user_prompt}
-                ],
-                temperature=0.2
-            )
-            
-            proposed_fix = response.choices[0].message.content.strip()
-            # Failsafe cleanup
-            if proposed_fix.startswith("```python"): proposed_fix = proposed_fix[9:]
-            if proposed_fix.startswith("```"): proposed_fix = proposed_fix[3:]
-            if proposed_fix.endswith("```"): proposed_fix = proposed_fix[:-3]
-                
-            action = CodeArenaAction(proposed_fix=proposed_fix.strip())
-            
-            obs, reward, done, info = env.step(action)
-            print(f"[STEP] Action taken. Reward received: {reward:.3f}. Task ID: {info['task_id']}")
-            
-        except Exception as e:
-            print(f"[STEP] Warning: Exception occurred: {str(e)}")
-            break
-            
-        step += 1
-        
-    print(f"[END] Inference Complete. Executed {step} step(s).")
+            try:
+                response = client.chat.completions.create(
+                    model="gpt-4o",  # Replace with desired model
+                    messages=[
+                        {"role": "system", "content": system_prompt},
+                        {"role": "user", "content": user_prompt},
+                    ],
+                    temperature=0.2,
+                )
+
+                proposed_fix = response.choices[0].message.content.strip()
+                # Failsafe cleanup
+                if proposed_fix.startswith("```python"):
+                    proposed_fix = proposed_fix[9:]
+                if proposed_fix.startswith("```"):
+                    proposed_fix = proposed_fix[3:]
+                if proposed_fix.endswith("```"):
+                    proposed_fix = proposed_fix[:-3]
+
+                action = CodeArenaAction(proposed_fix=proposed_fix.strip())
+
+                obs, reward, done, info = env.step(action)
+                print(
+                    f"[STEP] Action taken. Reward received: {reward:.3f}. "
+                    f"Task ID: {info['task_id']}"
+                )
+
+            except Exception as e:
+                print(f"[STEP] Warning: Exception occurred: {str(e)}")
+                break
+
+            step += 1
+
+        print(f"[END] Inference Complete. Executed {step} step(s).")
+        return {
+            "action": "analyze_code",
+            "explanation": f"Inference completed after {step} step(s).",
+        }
+
+    except Exception as e:
+        print(f"[ERROR] Top-level fallback triggered: {e}")
+        return {
+            "action": "analyze_code",
+            "explanation": f"Fallback due to error: {str(e)}",
+        }
+
 
 if __name__ == "__main__":
-    run_inference()
+    result = run_inference()
+    print(result)