"""四库统一注册表：异步生命周期编排。

启动：逐库 init，失败按指数退避重试；DB_STRICT_STARTUP=true 时重试耗尽直接抛错阻止启动。
关闭：逆序 dispose。健康：check_ready_detail 返回带耗时明细，供 /health 与监控面板使用。
"""
import asyncio
import logging
import time

from . import milvus, mysql, neo4j, redis
from config.settings import settings

logger = logging.getLogger("config.database")

# 关闭顺序与设计一致：mysql → redis → neo4j → milvus
_DB_MODULES = (mysql, redis, neo4j, milvus)


def _name(m) -> str:
    return m.__name__.rsplit(".", 1)[-1]


async def _init_with_retry(m, strict: bool) -> bool:
    name = _name(m)
    retries = settings.db.conn_retries
    for attempt in range(retries):
        try:
            await m.init_db()
            return True
        except Exception as e:
            logger.warning(
                "[%s] init failed (attempt %d/%d): %s: %s",
                name, attempt + 1, retries, type(e).__name__, e,
            )
            if attempt < retries - 1:
                await asyncio.sleep(settings.db.retry_backoff_sec * (2**attempt))
    if strict:
        raise RuntimeError(f"[{name}] 初始化失败（{retries} 次尝试后）")
    return False


async def init_db() -> None:
    """手动预热（应用启动不自动调用，会话懒创建）：asyncio.run(database.init_db())"""
    for m in _DB_MODULES:
        await _init_with_retry(m, settings.db.strict_startup)


async def dispose() -> None:
    for m in _DB_MODULES:
        try:
            await m.dispose()
        except Exception as e:
            logger.warning("[%s] dispose failed: %s: %s", _name(m), type(e).__name__, e)


async def check_ready_detail() -> dict[str, dict]:
    """含耗时明细：{db: {status, ms}}。任一失败不影响其它库探测。"""
    out: dict[str, dict] = {}
    for m in _DB_MODULES:
        name = _name(m)
        t0 = time.perf_counter()
        try:
            await m.check_health()
            status = "ok"
        except Exception as e:
            status = f"down: {type(e).__name__}"
        out[name] = {"status": status, "ms": round((time.perf_counter() - t0) * 1000, 1)}
    return out


async def check_ready() -> dict[str, str]:
    """兼容旧契约：{db: status_str}。"""
    return {k: v["status"] for k, v in (await check_ready_detail()).items()}