"""OllamaClient 单元测试（mock httpx，不发起真实网络请求）"""

from typing import Any

import httpx
import pytest

from app.services.ollama import OllamaClient


def _make_response(status_code: int, data: dict | None = None) -> httpx.Response:
    """构造带 request 上下文的 httpx.Response（raise_for_status 依赖 request）"""
    request = httpx.Request("POST", "http://localhost:11434/api/generate")
    if data is None:
        return httpx.Response(status_code, request=request)
    return httpx.Response(status_code, json=data, request=request)


class _FakeAsyncClient:
    """httpx.AsyncClient 替代品：记录请求参数，返回预设响应或抛出预设异常"""

    def __init__(
        self,
        captured: dict,
        response: httpx.Response | None = None,
        error: Exception | None = None,
        **kwargs: Any,
    ) -> None:
        self._captured = captured
        self._response = response
        self._error = error
        captured["timeout"] = kwargs.get("timeout")

    async def __aenter__(self) -> "_FakeAsyncClient":
        return self

    async def __aexit__(self, *args: object) -> bool:
        return False

    async def post(self, url: str, json: dict | None = None) -> httpx.Response:
        self._captured["url"] = url
        self._captured["json"] = json
        if self._error is not None:
            raise self._error
        assert self._response is not None
        return self._response

    async def get(self, url: str) -> httpx.Response:
        self._captured["url"] = url
        if self._error is not None:
            raise self._error
        assert self._response is not None
        return self._response


class TestGenerate:
    async def test_returns_response_field(self, monkeypatch: pytest.MonkeyPatch) -> None:
        captured: dict = {}
        monkeypatch.setattr(
            httpx,
            "AsyncClient",
            lambda **kw: _FakeAsyncClient(captured, response=_make_response(200, {"response": "生成结果"}), **kw),
        )
        client = OllamaClient(base_url="http://localhost:11434/", model="qwen2.5:1.5b")

        result = await client.generate("你好")

        assert result == "生成结果"
        # base_url 尾部斜杠被去除
        assert captured["url"] == "http://localhost:11434/api/generate"
        assert captured["json"] == {"model": "qwen2.5:1.5b", "prompt": "你好", "stream": False}
        assert "format" not in captured["json"]
        assert captured["timeout"] == 120.0

    async def test_json_mode_adds_format(self, monkeypatch: pytest.MonkeyPatch) -> None:
        captured: dict = {}
        monkeypatch.setattr(
            httpx,
            "AsyncClient",
            lambda **kw: _FakeAsyncClient(captured, response=_make_response(200, {"response": "{}"}), **kw),
        )
        client = OllamaClient(base_url="http://localhost:11434", model="qwen2.5:1.5b")

        await client.generate("你好", json_mode=True)

        assert captured["json"]["format"] == "json"

    async def test_http_error_status_raises(self, monkeypatch: pytest.MonkeyPatch) -> None:
        monkeypatch.setattr(
            httpx, "AsyncClient", lambda **kw: _FakeAsyncClient({}, response=_make_response(500), **kw)
        )
        client = OllamaClient(base_url="http://localhost:11434", model="qwen2.5:1.5b")

        with pytest.raises(httpx.HTTPStatusError):
            await client.generate("你好")


class TestIsAvailable:
    async def test_200_returns_true(self, monkeypatch: pytest.MonkeyPatch) -> None:
        captured: dict = {}
        monkeypatch.setattr(
            httpx,
            "AsyncClient",
            lambda **kw: _FakeAsyncClient(captured, response=_make_response(200, {"models": []}), **kw),
        )
        client = OllamaClient(base_url="http://localhost:11434", model="qwen2.5:1.5b")

        assert await client.is_available() is True
        assert captured["url"] == "http://localhost:11434/api/tags"
        assert captured["timeout"] == 5.0

    async def test_non_200_returns_false(self, monkeypatch: pytest.MonkeyPatch) -> None:
        monkeypatch.setattr(
            httpx, "AsyncClient", lambda **kw: _FakeAsyncClient({}, response=_make_response(503), **kw)
        )
        client = OllamaClient(base_url="http://localhost:11434", model="qwen2.5:1.5b")

        assert await client.is_available() is False

    async def test_connect_error_returns_false(self, monkeypatch: pytest.MonkeyPatch) -> None:
        monkeypatch.setattr(
            httpx, "AsyncClient", lambda **kw: _FakeAsyncClient({}, error=httpx.ConnectError("连接被拒绝"), **kw)
        )
        client = OllamaClient(base_url="http://localhost:11434", model="qwen2.5:1.5b")

        assert await client.is_available() is False