backend/utils/submission_logger.py

import json
import os
from datetime import datetime, timezone

# Log file lives at the project root (next to run.bat / run.sh)
_LOG_PATH = os.path.join(
    os.path.dirname(__file__),   # backend/utils/
    "..", "..",                   # → project root
    "submissions.jsonl"
)
_LOG_PATH = os.path.normpath(_LOG_PATH)


def log_submission(
    filename: str,
    overall_ai_score: float,
    overall_confidence: str,
    status_label: str,
    detector_results: dict,
    text_stats: dict,
    text_preview: str = "",
) -> None:
    """
    Append one JSON line to submissions.jsonl for every analysis.
    Safe to call from multiple threads — each write is a single os.write.
    """
    record = {
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "filename": filename,
        "overall_ai_score": round(overall_ai_score, 4),
        "overall_confidence": overall_confidence,
        "status_label": status_label,
        "text_preview": text_preview[:200],
        "text_stats": text_stats,
        "detectors": {
            name: {
                "score": round(res.get("score", 0), 4),
                "confidence": res.get("confidence"),
                "prediction": res.get("metadata", {}).get("prediction"),
                "ai_probability": round(res.get("metadata", {}).get("ai_probability", res.get("score", 0)), 4),
                "human_probability": round(res.get("metadata", {}).get("human_probability", 1 - res.get("score", 0)), 4),
            }
            for name, res in detector_results.items()
        },
    }

    line = json.dumps(record, ensure_ascii=False) + "\n"
    with open(_LOG_PATH, "a", encoding="utf-8") as f:
        f.write(line)