"""Persist useful failure evidence even when a worker must be terminated."""

import json
import os
from pathlib import Path
import uuid

from artemis.config import TRACES_PATH


def read_worker_outcome(session_id: str) -> dict:
    """Read a worker's terminal signal without waiting for hung SDK threads."""
    try:
        data = json.loads(
            (TRACES_PATH / session_id / "run_outcome.json").read_text(encoding="utf-8")
        )
        if (
            isinstance(data, dict)
            and data.get("worker_finalized") is True
            and data.get("task_status")
            in {
                "failed",
                "completed",
                "cancelled",
                "interrupted",
            }
        ):
            return data
    except (OSError, ValueError):
        pass  # Atomic outcome is absent until the task finalizes.
    return {}


def save_failure_result(session_id: str, error: str, *, code: str = "execution_failed") -> None:
    if not session_id or not all(c.isalnum() or c in "-_" for c in session_id):
        raise ValueError("无效的任务编号")
    directory = TRACES_PATH / session_id
    directory.mkdir(parents=True, exist_ok=True)
    payload: dict = {}
    try:
        previous = json.loads((directory / "result.json").read_text(encoding="utf-8"))
        if isinstance(previous, dict):
            payload.update(previous)
    except (OSError, ValueError):
        pass  # Missing/truncated results are expected after a killed worker.
    payload.update(
        {
            "status": "failed",
            "task_status": "failed",
            "explanation": error,
            "error": error,
            "code": code,
            "worker_finalized": True,
            "tests": payload.get("tests") or {},
        }
    )
    for name in ("result.json", "run_outcome.json"):
        target = directory / name
        temporary = target.with_name(f".{name}.{uuid.uuid4().hex}.tmp")
        try:
            temporary.write_text(json.dumps(payload, ensure_ascii=False), encoding="utf-8")
            os.replace(temporary, target)
        finally:
            temporary.unlink(missing_ok=True)