"""FastMCP must import without the legacy httpx/httpcore packages.

FastMCP depends on httpx2 exclusively; legacy httpx remains importable in the
test environment only as a transitive dependency of optional LLM SDKs. That
masks clean-install regressions: an accidental ``import httpx`` (directly or
via a third-party integration such as authlib's httpx client) passes CI but
breaks any install without those extras.

These tests simulate a clean install by blocking legacy httpx imports at the
meta-path level and verify that ordinary server startup leaves both legacy
packages unloaded.
"""

import subprocess
import sys
import textwrap

import pytest

_BLOCKER_SCRIPT = textwrap.dedent(
    """
    import sys

    class _LegacyHttpxBlocker:
        blocked = {"httpx", "httpcore", "pytest_httpx"}

        def find_spec(self, name, path=None, target=None):
            if name.split(".")[0] in self.blocked:
                raise ImportError(
                    f"{name} is blocked: FastMCP must not require legacy httpx"
                )
            return None

    sys.meta_path.insert(0, _LegacyHttpxBlocker())

    import fastmcp.cli.apps_dev
    import fastmcp.client.client
    import fastmcp.server.auth.oauth_proxy.proxy
    import fastmcp.server.server
    import fastmcp.utilities.openapi.director

    print("OK")
    """
)

_STARTUP_SCRIPT = textwrap.dedent(
    """
    import sys

    from fastmcp import FastMCP

    server = FastMCP("Legacy httpx import guard")
    app = server.http_app(transport="http", stateless_http=True)
    assert app is not None

    loaded = [
        name
        for name in sys.modules
        if name == "httpx"
        or name.startswith("httpx.")
        or name == "httpcore"
        or name.startswith("httpcore.")
    ]
    assert not loaded, loaded
    """
)


@pytest.mark.subprocess_heavy
def test_fastmcp_imports_without_legacy_httpx():
    result = subprocess.run(
        [sys.executable, "-c", _BLOCKER_SCRIPT],
        capture_output=True,
        text=True,
        timeout=30,
    )
    assert result.returncode == 0, (
        f"Import failed with legacy httpx blocked:\n{result.stderr}"
    )
    assert "OK" in result.stdout


@pytest.mark.subprocess_heavy
def test_default_http_app_does_not_load_legacy_httpx():
    result = subprocess.run(
        [sys.executable, "-c", _STARTUP_SCRIPT],
        capture_output=True,
        text=True,
        timeout=30,
    )
    assert result.returncode == 0, result.stderr