"""FastAPI contracts that do not download model weights."""

from pathlib import Path

from fastapi.testclient import TestClient

from app import create_app
from config import Settings
from core.loader import ModelLoader


def make_app(tmp_path: Path):
    ModelLoader.reset_instance()
    settings = Settings(
        output_folder=tmp_path / "output",
        tmp_folder=tmp_path / "tmp",
        static_folder=tmp_path / "static",
        device="cpu",
    )
    return create_app(settings)


def test_health_does_not_load_a_model(tmp_path: Path) -> None:
    application = make_app(tmp_path)
    with TestClient(application) as client:
        response = client.get("/health")

    assert response.status_code == 200
    assert response.json()["status"] == "ok"
    assert response.json()["active_model"] is None


def test_root_redirects_to_gradio_ui(tmp_path: Path) -> None:
    application = make_app(tmp_path)
    with TestClient(application) as client:
        response = client.get("/?__theme=dark", follow_redirects=False)
        direct_response = client.get("/ui", follow_redirects=False)

    assert response.status_code == 307
    assert response.headers["location"] == "/ui/?__theme=dark"
    assert direct_response.status_code == 307
    assert direct_response.headers["location"] == "/ui/"


def test_mounted_gradio_ui_runtime_options(tmp_path: Path) -> None:
    application = make_app(tmp_path)
    mount = next(
        route
        for route in application.routes
        if route.path == "/ui" and hasattr(route.app, "get_blocks")
    )

    blocks = mount.app.get_blocks()
    assert blocks.ssr_mode is False
    assert blocks.mcp_server is True


def test_validation_errors_have_stable_shape(tmp_path: Path) -> None:
    application = make_app(tmp_path)
    with TestClient(application) as client:
        response = client.post(
            "/api/image",
            json={"prompt": "city", "width": 257, "height": 768, "steps": 4, "seed": 1},
        )

    assert response.status_code == 400
    assert response.json()["success"] is False
    assert response.json()["code"] == "invalid_dimensions"
    assert response.headers["X-Request-ID"]