"""Contract tests for the Headroom Streamable HTTP MCP transport."""

from __future__ import annotations

import httpx
import pytest

pytest.importorskip("mcp")

from mcp.client.session import ClientSession
from mcp.client.streamable_http import streamable_http_client

from headroom.ccr.mcp_http import (
    create_streamable_http_app,
    create_streamable_http_session_manager,
)
from headroom.ccr.mcp_server import create_ccr_mcp_server

pytestmark = pytest.mark.anyio


@pytest.fixture
def anyio_backend() -> str:
    return "asyncio"


async def test_streamable_http_initialize_and_list_tools() -> None:
    server = create_ccr_mcp_server()
    session_manager = create_streamable_http_session_manager(server)
    app = create_streamable_http_app(session_manager, path="/mcp")
    transport = httpx.ASGITransport(app=app)

    async with session_manager.run():
        async with httpx.AsyncClient(
            transport=transport, base_url="http://testserver"
        ) as http_client:
            async with streamable_http_client(
                "http://testserver/mcp",
                http_client=http_client,
                terminate_on_close=False,
            ) as (read_stream, write_stream, get_session_id):
                async with ClientSession(read_stream, write_stream) as session:
                    initialize_result = await session.initialize()
                    list_tools_result = await session.list_tools()

    tool_names = [tool.name for tool in list_tools_result.tools]
    assert initialize_result.protocolVersion
    assert get_session_id() is not None
    assert "headroom_compress" in tool_names
    assert "headroom_retrieve" in tool_names
    assert "headroom_stats" in tool_names