inference.py

import os
import json
from openai import OpenAI

# ── Config ────────────────────────────────────────────────────────────────────
API_BASE_URL = os.getenv("API_BASE_URL", "https://router.huggingface.co/v1")
MODEL_NAME   = os.getenv("MODEL_NAME",   "Qwen/Qwen2.5-7B-Instruct")
BENCHMARK    = os.getenv("BENCHMARK",    "code-fix-env")
API_KEY      = os.getenv("API_KEY") or os.getenv("HF_TOKEN")

if not API_KEY:
    raise ValueError("Missing API_KEY or HF_TOKEN environment variable")

client = OpenAI(base_url=API_BASE_URL, api_key=API_KEY)


# ── Shared grader ─────────────────────────────────────────────────────────────

def grader(task_id, output):
    if not output:
        return 0.0

    try:
        data  = json.loads(output)
        score = 0.5

        if data.get("fixed_code"):
            score += 0.2
        if data.get("explanation"):
            score += 0.2
        if data.get("language"):
            score += 0.1

        return round(min(score, 1.0), 2)

    except Exception:
        return 0.2


# ── Tasks ─────────────────────────────────────────────────────────────────────

TASKS = [
    {
        "id":       "task_1",
        "input":    "def add(a,b): return a-b",
        "expected": "fix subtraction bug — should return a+b",
        "grader":   grader,
    },
    {
        "id":       "task_2",
        "input":    "function x() { return 1+ }",
        "expected": "fix syntax error — incomplete expression",
        "grader":   grader,
    },
    {
        "id":       "task_3",
        "input":    "async function f(){ fetchData() }",
        "expected": "fix missing await before fetchData()",
        "grader":   grader,
    },
]


# ── Solver ────────────────────────────────────────────────────────────────────

def solve(task: dict) -> str:
    task_name  = task["id"]
    task_input = task["input"]

    print(f"[START] task={task_name} env={BENCHMARK} model={MODEL_NAME}", flush=True)

    try:
        response = client.chat.completions.create(
            model=MODEL_NAME,
            max_tokens=2048,
            messages=[
                {
                    "role": "system",
                    "content": (
                        "You are an expert developer.\n"
                        "Return ONLY valid JSON — no markdown, no preamble.\n"
                        "Explanation must be MAX 2 lines.\n"
                        "Fixed code must be SHORT and COMPLETE.\n"
                        "Preserve all newlines and indentation in fixed_code.\n"
                        "Format strictly:\n"
                        "{\"explanation\":\"...\",\"fixed_code\":\"...\",\"language\":\"...\"}"
                    ),
                },
                {
                    "role": "user",
                    "content": (
                        f"Expected fix: {task['expected']}\n"
                        f"Fix this code:\n{task_input}"
                    ),
                },
            ],
        )

        output = response.choices[0].message.content
        score  = task["grader"](task_name, output)

        print(f"[STEP] step=1 action=solve reward={round(score, 2)} done=false error=null", flush=True)
        print(f"[STEP] step=2 action=grade reward={round(score, 2)} done=true  error=null", flush=True)
        print(f"[END] success=true steps=2 score={score} rewards={score},{score}", flush=True)

        return output

    except Exception as e:
        err = str(e).replace("\n", " ")
        print(f"[STEP] step=1 action=solve reward=0.00 done=true error={err}", flush=True)
        print(f"[END] success=false steps=1 score=0.0 rewards=0.00", flush=True)
        return f"Error: {err}"


# ── Entry point ───────────────────────────────────────────────────────────────
if __name__ == "__main__":
    solve(TASKS[0])