"""就绪探针（B3）单元测试：Milvus 可用/不可用/客户端缺失/探测超时。"""

import asyncio
from typing import Any

import pytest

from app.service import health_service
from app.service.health_service import HealthService


class FakeMilvusClient:
    def __init__(self, *, version: Any = "pkg/v2.5.4", error: Exception | None = None,
                 delay: float = 0.0) -> None:
        self._version = version
        self._error = error
        self._delay = delay
        self.closed = False

    async def get_server_version(self) -> Any:
        if self._delay:
            await asyncio.sleep(self._delay)
        if self._error is not None:
            raise self._error
        return self._version

    async def close(self) -> None:
        self.closed = True


def patch_client(monkeypatch: pytest.MonkeyPatch, client: Any) -> None:
    monkeypatch.setattr(health_service, "_create_milvus_client", lambda uri, token: client)


async def test_available_milvus_reports_ok(monkeypatch: pytest.MonkeyPatch) -> None:
    client = FakeMilvusClient()
    patch_client(monkeypatch, client)
    ready, state = await HealthService()._milvus_ready()
    assert (ready, state) == (True, "ok")
    assert client.closed is True


@pytest.mark.parametrize("error", [ConnectionError("refused"), RuntimeError("grpc down")])
async def test_unavailable_milvus_reports_unavailable(
    monkeypatch: pytest.MonkeyPatch, error: Exception
) -> None:
    client = FakeMilvusClient(error=error)
    patch_client(monkeypatch, client)
    ready, state = await HealthService()._milvus_ready()
    assert (ready, state) == (False, "unavailable")
    assert client.closed is True


async def test_missing_pymilvus_reports_client_missing(monkeypatch: pytest.MonkeyPatch) -> None:
    def missing(uri: str, token: str) -> Any:
        raise ImportError("No module named 'pymilvus'")

    monkeypatch.setattr(health_service, "_create_milvus_client", missing)
    ready, state = await HealthService()._milvus_ready()
    assert (ready, state) == (False, "client_missing")


async def test_probe_timeout_is_bounded(monkeypatch: pytest.MonkeyPatch) -> None:
    client = FakeMilvusClient(delay=5.0)
    patch_client(monkeypatch, client)
    ready, state = await HealthService(milvus_timeout_seconds=0.05)._milvus_ready()
    assert (ready, state) == (False, "timeout")


async def test_ready_reflects_real_milvus_probe(monkeypatch: pytest.MonkeyPatch) -> None:
    client = FakeMilvusClient(error=ConnectionError("milvus stopped"))
    patch_client(monkeypatch, client)

    async def redis_ok(_self: HealthService) -> bool:
        return True

    monkeypatch.setattr(HealthService, "_redis_ready", redis_ok)
    result = await HealthService().ready()
    assert result["checks"]["milvus"] is False
    assert result["probes"]["milvus"] == "unavailable"
    assert result["status"] == "degraded"


async def test_ready_is_ready_when_all_probes_pass(monkeypatch: pytest.MonkeyPatch) -> None:
    patch_client(monkeypatch, FakeMilvusClient())

    async def redis_ok(_self: HealthService) -> bool:
        return True

    monkeypatch.setattr(HealthService, "_redis_ready", redis_ok)
    result = await HealthService().ready()
    assert result["checks"]["milvus"] is True
    assert result["probes"]["milvus"] == "ok"
    assert result["checks"]["mysql"] is True


async def test_redis_failure_marks_readiness_degraded(monkeypatch: pytest.MonkeyPatch) -> None:
    async def unavailable(self: HealthService) -> bool:
        return False

    monkeypatch.setattr(HealthService, "_redis_ready", unavailable)
    patch_client(monkeypatch, FakeMilvusClient())
    service = HealthService()
    result = await service.ready()
    assert result["checks"]["redis"] is False
    assert result["status"] == "degraded"