"""Pipeline 章节级 Redis 锁：与 memoir pipeline / recompose_chapter 共用同一 key 空间。"""

from app.core.redis_lock import (
    RedisLockHandle,
    acquire_redis_lock,
    release_redis_lock,
)

ChapterPipelineLockHandle = RedisLockHandle


def _lock_key(user_id: str, stage: str) -> str:
    return f"lock:chapter:{user_id}:{stage}"


def acquire_chapter_pipeline_lock(
    user_id: str, stage: str, *, ttl_seconds: int
) -> ChapterPipelineLockHandle | None:
    """获取 `lock:chapter:{user_id}:{stage}`；失败返回 None。"""
    return acquire_redis_lock(_lock_key(user_id, stage), ttl_seconds=ttl_seconds)


def release_chapter_pipeline_lock(handle: ChapterPipelineLockHandle | None) -> None:
    release_redis_lock(handle)