"""MCP Client 单元测试"""

import json
from unittest.mock import AsyncMock

import httpx
import pytest

from agentkit.mcp.client import MCPClient, MCPTool
from agentkit.mcp.transport import HTTPTransport, TransportError


# ── MCPClient 构造测试 ──────────────────────────────────────────


class TestMCPClientConstruction:
    """MCPClient 构造测试"""

    def test_construction_with_server_url(self):
        client = MCPClient(server_url="http://localhost:8080")
        assert client._server_url == "http://localhost:8080"
        assert client._transport is None
        assert client._timeout == 30
        assert client._tools_cache is None

    def test_construction_strips_trailing_slash(self):
        client = MCPClient(server_url="http://localhost:8080/")
        assert client._server_url == "http://localhost:8080"

    def test_construction_with_custom_timeout(self):
        client = MCPClient(server_url="http://localhost:8080", timeout=60)
        assert client._timeout == 60

    def test_construction_with_transport(self):
        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient(server_url="http://localhost:8080", transport=transport)
        assert client._transport is transport

    def test_from_transport_with_http_transport(self):
        transport = HTTPTransport(endpoint="http://localhost:8080/mcp")
        client = MCPClient.from_transport(transport)
        assert client._transport is transport
        assert client._server_url == "http://localhost:8080/mcp"

    def test_from_transport_preserves_endpoint(self):
        transport = HTTPTransport(endpoint="http://remote-server:3000/api")
        client = MCPClient.from_transport(transport)
        assert client._server_url == "http://remote-server:3000/api"


# ── MCPClient Transport 模式测试 ────────────────────────────────


class TestMCPClientTransportMode:
    """MCPClient Transport 模式测试"""

    async def test_list_tools_via_transport(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={
                "jsonrpc": "2.0",
                "id": 1,
                "result": {
                    "tools": [
                        {"name": "echo", "description": "Echo tool"},
                        {"name": "calc", "description": "Calculator"},
                    ]
                },
            },
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)

        tools = await client.list_tools()
        assert len(tools) == 2
        assert tools[0]["name"] == "echo"
        assert tools[1]["name"] == "calc"

        # 验证缓存
        assert client._tools_cache == tools

        await transport.disconnect()

    async def test_list_tools_transport_auto_connects(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={
                "jsonrpc": "2.0",
                "id": 1,
                "result": {"tools": [{"name": "search"}]},
            },
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)
        assert not transport.is_connected

        tools = await client.list_tools()
        assert len(tools) == 1
        assert transport.is_connected

        await transport.disconnect()

    async def test_call_tool_via_transport(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={
                "jsonrpc": "2.0",
                "id": 1,
                "result": {
                    "content": [{"type": "text", "text": "hello world"}],
                },
            },
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)

        result = await client.call_tool("echo", {"msg": "hello world"})
        assert result["content"][0]["text"] == "hello world"

        # 验证请求体为 JSON-RPC 格式
        request = httpx_mock.get_request()
        body = json.loads(request.content)
        assert body["jsonrpc"] == "2.0"
        assert body["method"] == "tools/call"
        assert body["params"]["name"] == "echo"
        assert body["params"]["arguments"] == {"msg": "hello world"}

        await transport.disconnect()

    async def test_call_tool_transport_auto_connects(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={
                "jsonrpc": "2.0",
                "id": 1,
                "result": {"content": []},
            },
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)
        assert not transport.is_connected

        await client.call_tool("test_tool", {})
        assert transport.is_connected

        await transport.disconnect()


# ── MCPClient 连接错误处理测试 ──────────────────────────────────


class TestMCPClientErrorHandling:
    """MCPClient 连接错误处理测试"""

    async def test_transport_error_propagates(self, httpx_mock):
        httpx_mock.add_exception(httpx.ConnectError("Connection refused"))

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)
        await transport.connect()

        with pytest.raises(TransportError, match="Request failed"):
            await client.list_tools()

        await transport.disconnect()


# ── JSON-RPC 2.0 请求格式测试 ───────────────────────────────────


class TestMCPClientJSONRPCFormat:
    """JSON-RPC 2.0 请求格式测试"""

    async def test_transport_list_tools_request_format(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={"jsonrpc": "2.0", "id": 1, "result": {"tools": []}},
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)

        await client.list_tools()

        request = httpx_mock.get_request()
        body = json.loads(request.content)
        assert body["jsonrpc"] == "2.0"
        assert "id" in body
        assert body["method"] == "tools/list"

        await transport.disconnect()

    async def test_transport_call_tool_request_format(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={"jsonrpc": "2.0", "id": 1, "result": {}},
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)

        await client.call_tool("search", {"query": "test"})

        request = httpx_mock.get_request()
        body = json.loads(request.content)
        assert body["jsonrpc"] == "2.0"
        assert "id" in body
        assert body["method"] == "tools/call"
        assert body["params"]["name"] == "search"
        assert body["params"]["arguments"] == {"query": "test"}

        await transport.disconnect()

    async def test_request_id_increments_across_calls(self, httpx_mock):
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={"jsonrpc": "2.0", "id": 1, "result": {"tools": []}},
        )
        httpx_mock.add_response(
            url="http://localhost:8080/",
            json={"jsonrpc": "2.0", "id": 2, "result": {}},
        )

        transport = HTTPTransport(endpoint="http://localhost:8080")
        client = MCPClient.from_transport(transport)

        await client.list_tools()
        await client.call_tool("test", {})

        requests = httpx_mock.get_requests()
        body1 = json.loads(requests[0].content)
        body2 = json.loads(requests[1].content)
        assert body1["id"] == 1
        assert body2["id"] == 2

        await transport.disconnect()


# ── MCPTool 测试 ────────────────────────────────────────────────


class TestMCPTool:
    """MCPTool 包装测试"""

    async def test_as_tool_creates_mcp_tool(self):
        client = MCPClient(server_url="http://localhost:8080")
        tool = client.as_tool("search", description="Search the web")

        assert isinstance(tool, MCPTool)
        assert tool.name == "search"
        assert tool.description == "Search the web"
        assert tool._client is client
        assert "mcp" in tool.tags

    async def test_mcp_tool_execute_text_content(self):
        """execute 应解析 content[0].text 中的 JSON。"""
        client = MCPClient(server_url="http://localhost:8080")
        client.call_tool = AsyncMock(  # type: ignore[method-assign]
            return_value={
                "content": [{"type": "text", "text": '{"answer": 42}'}],
            }
        )
        tool = client.as_tool("ask", description="Ask a question")

        result = await tool.execute(question="meaning of life")
        assert result == {"answer": 42}

    async def test_mcp_tool_execute_non_json_text(self):
        """content[0].text 为纯文本时返回 {"result": text}。"""
        client = MCPClient(server_url="http://localhost:8080")
        client.call_tool = AsyncMock(  # type: ignore[method-assign]
            return_value={
                "content": [{"type": "text", "text": "plain text response"}],
            }
        )
        tool = client.as_tool("echo", description="Echo input")

        result = await tool.execute(msg="hello")
        assert result == {"result": "plain text response"}

    async def test_mcp_tool_execute_no_content(self):
        """无 content 字段时返回原始 dict。"""
        client = MCPClient(server_url="http://localhost:8080")
        client.call_tool = AsyncMock(  # type: ignore[method-assign]
            return_value={"status": "ok", "data": "some data"}
        )
        tool = client.as_tool("status", description="Check status")

        result = await tool.execute()
        assert result == {"status": "ok", "data": "some data"}