"""健康检查模块（待实现）。

提供可插拔的健康检查功能，支持 Kubernetes 标准探针。

TODO: 实现以下功能
"""

from __future__ import annotations

# =============================================================================
# 以下为伪代码，待实现
# =============================================================================

# from abc import ABC, abstractmethod
# from enum import Enum
# from typing import Literal
# import asyncio
# from dataclasses import dataclass, field
#
#
# class ProbeType(str, Enum):
#     """探针类型。"""
#     LIVENESS = "liveness"    # 存活检查，失败会重启
#     READINESS = "readiness"  # 就绪检查，失败从负载均衡移除
#     STARTUP = "startup"      # 启动检查
#
#
# @dataclass
# class HealthCheck:
#     """健康检查项。"""
#     name: str
#     check_func: Callable[[], Awaitable[None]]
#     timeout: float = 5.0
#     critical: bool = True  # 失败是否导致整体失败
#
#     async def run(self) -> tuple[str, bool, str | None]:
#         """执行检查。
#
#         Returns:
#             (name, success, error_message)
#         """
#         try:
#             await asyncio.wait_for(self.check_func(), timeout=self.timeout)
#             return (self.name, True, None)
#         except asyncio.TimeoutError:
#             return (self.name, False, f"Timeout after {self.timeout}s")
#         except Exception as e:
#             return (self.name, False, str(e))
#
#
# @dataclass
# class HealthResult:
#     """健康检查结果。"""
#     status: Literal["healthy", "unhealthy", "degraded"]
#     checks: dict[str, dict] = field(default_factory=dict)
#
#
# class HealthManager:
#     """可插拔健康检查管理器。"""
#
#     _checks: dict[str, list[HealthCheck]] = {
#         "liveness": [],
#         "readiness": [],
#         "startup": [],
#     }
#
#     @classmethod
#     def register(
#         cls,
#         name: str,
#         probe: Literal["liveness", "readiness", "startup"] = "readiness",
#         timeout: float = 5.0,
#         critical: bool = True,
#     ):
#         """装饰器注册检查器。
#
#         用法:
#             @HealthManager.register("database", probe="readiness")
#             async def check_db():
#                 await db.execute("SELECT 1")
#
#             @HealthManager.register("redis", probe="readiness", critical=False)
#             async def check_redis():
#                 await redis.ping()
#
#             @HealthManager.register("app", probe="liveness")
#             async def check_app():
#                 return True
#         """
#         def decorator(func):
#             cls._checks[probe].append(
#                 HealthCheck(name, func, timeout, critical)
#             )
#             return func
#         return decorator
#
#     @classmethod
#     async def check(
#         cls,
#         probe: str,
#         detailed: bool = False,
#     ) -> HealthResult:
#         """执行指定探针的所有检查（并行+超时）。
#
#         Args:
#             probe: 探针类型 (liveness/readiness/startup)
#             detailed: 是否返回详细信息
#
#         Returns:
#             HealthResult: 检查结果
#         """
#         checks = cls._checks.get(probe, [])
#         if not checks:
#             return HealthResult(status="healthy")
#
#         # 并行执行所有检查
#         results = await asyncio.gather(
#             *[c.run() for c in checks],
#             return_exceptions=True
#         )
#
#         # 汇总结果
#         all_ok = True
#         has_degraded = False
#         check_results = {}
#
#         for check, result in zip(checks, results):
#             if isinstance(result, Exception):
#                 name, success, error = check.name, False, str(result)
#             else:
#                 name, success, error = result
#
#             check_results[name] = {
#                 "status": "ok" if success else "error",
#                 "error": error,
#             }
#
#             if not success:
#                 if check.critical:
#                     all_ok = False
#                 else:
#                     has_degraded = True
#
#         if all_ok:
#             status = "degraded" if has_degraded else "healthy"
#         else:
#             status = "unhealthy"
#
#         return HealthResult(
#             status=status,
#             checks=check_results if detailed else {},
#         )
#
#     @classmethod
#     def clear(cls) -> None:
#         """清除所有注册的检查器。"""
#         for probe in cls._checks:
#             cls._checks[probe] = []
#
#
# # =============================================================================
# # 内置检查器
# # =============================================================================
#
#
# def register_database_check(db_manager) -> None:
#     """注册数据库健康检查。"""
#     @HealthManager.register("database", probe="readiness")
#     async def check_database():
#         await db_manager.health_check()
#
#
# def register_cache_check(cache_manager) -> None:
#     """注册缓存健康检查。"""
#     @HealthManager.register("cache", probe="readiness", critical=False)
#     async def check_cache():
#         await cache_manager.get("__health__", default=None)
#
#
# def register_redis_check(redis_client) -> None:
#     """注册 Redis 健康检查。"""
#     @HealthManager.register("redis", probe="readiness", critical=False)
#     async def check_redis():
#         await redis_client.ping()
#
#
# # =============================================================================
# # 路由注册（在 FoundationApp 中调用）
# # =============================================================================
#
#
# def setup_health_routes(app) -> None:
#     """注册健康检查路由。
#
#     路由:
#         GET /health/live   -> liveness checks
#         GET /health/ready  -> readiness checks
#         GET /health/startup -> startup checks
#     """
#     from fastapi import status
#     from fastapi.responses import JSONResponse
#
#     @app.get("/health/live", tags=["health"])
#     async def liveness():
#         result = await HealthManager.check("liveness")
#         return JSONResponse(
#             content={"status": result.status},
#             status_code=status.HTTP_200_OK if result.status == "healthy"
#                 else status.HTTP_503_SERVICE_UNAVAILABLE,
#         )
#
#     @app.get("/health/ready", tags=["health"])
#     async def readiness():
#         result = await HealthManager.check("readiness", detailed=True)
#         return JSONResponse(
#             content={"status": result.status, "checks": result.checks},
#             status_code=status.HTTP_200_OK if result.status != "unhealthy"
#                 else status.HTTP_503_SERVICE_UNAVAILABLE,
#         )
#
#     @app.get("/health/startup", tags=["health"])
#     async def startup():
#         result = await HealthManager.check("startup")
#         return JSONResponse(
#             content={"status": result.status},
#             status_code=status.HTTP_200_OK if result.status == "healthy"
#                 else status.HTTP_503_SERVICE_UNAVAILABLE,
#         )


__all__: list[str] = []
