import io

import anyio
import pytest

from mcp.server.stdio import stdio_server
from mcp.shared.message import SessionMessage
from mcp.types import JSONRPCMessage, JSONRPCRequest, JSONRPCResponse


@pytest.mark.anyio
async def test_stdio_server():
    stdin = io.StringIO()
    stdout = io.StringIO()

    messages = [
        JSONRPCMessage(root=JSONRPCRequest(jsonrpc="2.0", id=1, method="ping")),
        JSONRPCMessage(root=JSONRPCResponse(jsonrpc="2.0", id=2, result={})),
    ]

    for message in messages:
        stdin.write(message.model_dump_json(by_alias=True, exclude_none=True) + "\n")
    stdin.seek(0)

    async with stdio_server(stdin=anyio.AsyncFile(stdin), stdout=anyio.AsyncFile(stdout)) as (
        read_stream,
        write_stream,
    ):
        received_messages: list[JSONRPCMessage] = []
        async with read_stream:
            async for message in read_stream:
                if isinstance(message, Exception):  # pragma: no cover
                    raise message
                received_messages.append(message.message)
                if len(received_messages) == 2:
                    break

        # Verify received messages
        assert len(received_messages) == 2
        assert received_messages[0] == JSONRPCMessage(root=JSONRPCRequest(jsonrpc="2.0", id=1, method="ping"))
        assert received_messages[1] == JSONRPCMessage(root=JSONRPCResponse(jsonrpc="2.0", id=2, result={}))

        # Test sending responses from the server
        responses = [
            JSONRPCMessage(root=JSONRPCRequest(jsonrpc="2.0", id=3, method="ping")),
            JSONRPCMessage(root=JSONRPCResponse(jsonrpc="2.0", id=4, result={})),
        ]

        async with write_stream:
            for response in responses:
                session_message = SessionMessage(response)
                await write_stream.send(session_message)

    stdout.seek(0)
    output_lines = stdout.readlines()
    assert len(output_lines) == 2

    received_responses = [JSONRPCMessage.model_validate_json(line.strip()) for line in output_lines]
    assert len(received_responses) == 2
    assert received_responses[0] == JSONRPCMessage(root=JSONRPCRequest(jsonrpc="2.0", id=3, method="ping"))
    assert received_responses[1] == JSONRPCMessage(root=JSONRPCResponse(jsonrpc="2.0", id=4, result={}))
