"""프로젝트 간 공유되는 워크플로우 상태 유틸리티."""

import json
import threading
from pathlib import Path
from typing import Any

from common_util.common_util_json import atomic_write_json

_WORKFLOW_LOCK = threading.Lock()


def load_project_workflow(project_root: str | Path) -> dict[str, Any]:
    """프로젝트 루트의 workflow.json을 읽고 없으면 초기 상태를 반환한다."""
    workflow_path = Path(project_root) / "workflow.json"
    if not workflow_path.exists():
        return {
            "current_stage": "scan",
            "completed": [],
            "stale_from": None,
            "stage1_confirmed": None,
        }

    with workflow_path.open("r", encoding="utf-8") as workflow_file:
        workflow = json.load(workflow_file)
    if not isinstance(workflow, dict):
        raise ValueError("workflow.json의 최상위 값은 객체여야 합니다.")
    return workflow


def patch_project_workflow_stale(project_root: str | Path, stale_from: str | None) -> None:
    """기존 workflow.json의 다른 상태를 보존하며 stale_from만 갱신한다."""
    workflow_path = Path(project_root) / "workflow.json"
    if not workflow_path.exists():
        return

    with _WORKFLOW_LOCK:
        workflow = load_project_workflow(project_root)
        if workflow.get("stale_from") == stale_from:
            return
        workflow["stale_from"] = stale_from
        atomic_write_json(workflow_path, workflow)