"""app.api.client_ip is shared by the login/registration throttles (B-33) and
the SSE per-IP subscriber cap (B-38) — both depend on it correctly preferring
X-Forwarded-For (Caddy reverse-proxies every request, see Caddyfile) over
request.client.host, which would otherwise be the proxy's own address."""

from starlette.requests import Request

from app.api.client_ip import client_ip


def _request(*, forwarded: str | None = None, client_host: str | None = "127.0.0.1") -> Request:
    headers = [(b"x-forwarded-for", forwarded.encode())] if forwarded else []
    scope = {
        "type": "http",
        "headers": headers,
        "client": (client_host, 12345) if client_host else None,
    }
    return Request(scope)


def test_client_ip_prefers_x_forwarded_for():
    request = _request(forwarded="5.6.7.8", client_host="10.0.0.1")
    assert client_ip(request) == "5.6.7.8"


def test_client_ip_takes_the_first_hop_of_a_forwarded_chain():
    request = _request(forwarded="5.6.7.8, 10.0.0.1, 172.17.0.1")
    assert client_ip(request) == "5.6.7.8"


def test_client_ip_strips_whitespace():
    request = _request(forwarded="  5.6.7.8  , 10.0.0.1")
    assert client_ip(request) == "5.6.7.8"


def test_client_ip_falls_back_to_request_client_without_the_header():
    request = _request(forwarded=None, client_host="10.0.0.1")
    assert client_ip(request) == "10.0.0.1"


def test_client_ip_falls_back_to_unknown_with_neither():
    request = _request(forwarded=None, client_host=None)
    assert client_ip(request) == "unknown"