import sys
import types
from unittest.mock import patch, AsyncMock, MagicMock

from httpx import AsyncClient

from tests.conftest import auth_header


def _make_aiomysql_mock():
    aiomysql = MagicMock()
    aiomysql.connect = AsyncMock()
    aiomysql.DictCursor = MagicMock()
    return aiomysql


class TestListInstances:
    async def test_list_instances(self, client: AsyncClient, admin_user, admin_token):
        resp = await client.get("/api/v1/instances", headers=auth_header(admin_token))
        assert resp.status_code == 200
        assert isinstance(resp.json(), list)

    async def test_list_instances_filter_db_type(self, client: AsyncClient, admin_token, test_instance):
        resp = await client.get(
            "/api/v1/instances?db_type=mysql",
            headers=auth_header(admin_token),
        )
        assert resp.status_code == 200
        data = resp.json()
        assert all(i["db_type"] == "mysql" for i in data)

    async def test_list_instances_filter_env(self, client: AsyncClient, admin_token, test_instance):
        resp = await client.get(
            "/api/v1/instances?env=development",
            headers=auth_header(admin_token),
        )
        assert resp.status_code == 200
        data = resp.json()
        assert all(i["env"] == "development" for i in data)

    async def test_list_instances_non_admin_no_group(
        self, client: AsyncClient, developer_user, developer_token, test_instance
    ):
        """非 admin 且无权限组，只能看到公开实例（group_id=None）。"""
        resp = await client.get(
            "/api/v1/instances",
            headers=auth_header(developer_token),
        )
        assert resp.status_code == 200
        # test_instance has no group_id, so it should be visible
        data = resp.json()
        assert any(i["name"] == "测试MySQL" for i in data)

    async def test_list_instances_unauthorized(self, client: AsyncClient):
        resp = await client.get("/api/v1/instances")
        assert resp.status_code == 401


class TestCreateInstance:
    async def test_create_instance(self, client: AsyncClient, admin_token):
        resp = await client.post("/api/v1/instances", headers=auth_header(admin_token), json={
            "name": "生产MySQL",
            "db_type": "mysql",
            "host": "10.0.0.1",
            "port": 3306,
            "username": "root",
            "password": "secret",
            "database": "prod",
            "env": "production",
        })
        assert resp.status_code == 201
        data = resp.json()
        assert data["name"] == "生产MySQL"
        assert data["db_type"] == "mysql"

    async def test_create_instance_non_admin(self, client: AsyncClient, developer_token):
        resp = await client.post("/api/v1/instances", headers=auth_header(developer_token), json={
            "name": "非法创建",
            "db_type": "mysql",
            "host": "10.0.0.1",
            "port": 3306,
            "username": "root",
            "password": "secret",
        })
        assert resp.status_code == 403


class TestGetInstance:
    async def test_get_instance(self, client: AsyncClient, test_instance, admin_token):
        resp = await client.get(
            f"/api/v1/instances/{test_instance.id}",
            headers=auth_header(admin_token),
        )
        assert resp.status_code == 200
        assert resp.json()["name"] == "测试MySQL"

    async def test_get_nonexistent_instance(self, client: AsyncClient, admin_token):
        resp = await client.get("/api/v1/instances/9999", headers=auth_header(admin_token))
        assert resp.status_code == 404


class TestUpdateInstance:
    async def test_update_instance(self, client: AsyncClient, test_instance, admin_token):
        resp = await client.put(
            f"/api/v1/instances/{test_instance.id}",
            headers=auth_header(admin_token),
            json={"name": "改名MySQL"},
        )
        assert resp.status_code == 200
        assert resp.json()["name"] == "改名MySQL"

    async def test_update_instance_not_found(self, client: AsyncClient, admin_token):
        resp = await client.put(
            "/api/v1/instances/9999",
            headers=auth_header(admin_token),
            json={"name": "不存在"},
        )
        assert resp.status_code == 404

    async def test_update_instance_forbidden_developer(
        self, client: AsyncClient, test_instance, developer_token
    ):
        resp = await client.put(
            f"/api/v1/instances/{test_instance.id}",
            headers=auth_header(developer_token),
            json={"name": "非法修改"},
        )
        assert resp.status_code == 403

    async def test_update_instance_dba_allowed(
        self, client: AsyncClient, test_instance, dba_token
    ):
        resp = await client.put(
            f"/api/v1/instances/{test_instance.id}",
            headers=auth_header(dba_token),
            json={"description": "DBA修改的描述"},
        )
        assert resp.status_code == 200


class TestDeleteInstance:
    async def test_delete_instance(self, client: AsyncClient, test_instance, admin_token):
        resp = await client.delete(
            f"/api/v1/instances/{test_instance.id}",
            headers=auth_header(admin_token),
        )
        assert resp.status_code == 200

    async def test_delete_instance_not_found(self, client: AsyncClient, admin_token):
        resp = await client.delete(
            "/api/v1/instances/9999",
            headers=auth_header(admin_token),
        )
        assert resp.status_code == 404

    async def test_delete_instance_forbidden_developer(
        self, client: AsyncClient, test_instance, developer_token
    ):
        resp = await client.delete(
            f"/api/v1/instances/{test_instance.id}",
            headers=auth_header(developer_token),
        )
        assert resp.status_code == 403


class TestConnectionTest:
    async def test_connection_test(self, client: AsyncClient, test_instance, admin_token):
        from contextlib import asynccontextmanager

        mock_cursor = AsyncMock()
        mock_cursor.execute = AsyncMock()
        mock_cursor.fetchone.return_value = ("8.0.30",)

        @asynccontextmanager
        async def mock_cursor_ctx(*args, **kwargs):
            yield mock_cursor

        mock_conn = AsyncMock()
        mock_conn.cursor = mock_cursor_ctx
        mock_conn.close = MagicMock()

        mock_aiomysql = _make_aiomysql_mock()
        mock_aiomysql.connect = AsyncMock(return_value=mock_conn)

        with patch.dict(sys.modules, {"aiomysql": mock_aiomysql}):
            resp = await client.post(
                f"/api/v1/instances/{test_instance.id}/test",
                headers=auth_header(admin_token),
            )
            assert resp.status_code == 200
            data = resp.json()
            assert data["success"] is True