"""Contract tests for the LangGraph-compatible assistants endpoints."""

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient

from app.gateway.routers import assistants_compat


def _assistant(name: str) -> assistants_compat.AssistantResponse:
    return assistants_compat.AssistantResponse(
        assistant_id=name,
        graph_id="lead_agent",
        name=name,
    )


def _make_app(monkeypatch: pytest.MonkeyPatch) -> FastAPI:
    app = FastAPI()
    app.include_router(assistants_compat.router)
    monkeypatch.setattr(
        assistants_compat,
        "_list_assistants",
        lambda: [_assistant("lead_agent"), _assistant("researcher"), _assistant("writer")],
    )
    return app


@pytest.mark.parametrize(
    "body",
    [
        {"limit": 0},
        {"limit": -1},
        {"limit": 1001},
        {"offset": -1},
    ],
)
def test_search_rejects_invalid_pagination(monkeypatch: pytest.MonkeyPatch, body: dict[str, int]) -> None:
    with TestClient(_make_app(monkeypatch)) as client:
        response = client.post("/api/assistants/search", json=body)

    assert response.status_code == 422


def test_search_accepts_contract_maximum_limit(monkeypatch: pytest.MonkeyPatch) -> None:
    with TestClient(_make_app(monkeypatch)) as client:
        response = client.post("/api/assistants/search", json={"limit": 1000})

    assert response.status_code == 200
    assert [assistant["assistant_id"] for assistant in response.json()] == ["lead_agent", "researcher", "writer"]


def test_search_preserves_default_and_positive_offset(monkeypatch: pytest.MonkeyPatch) -> None:
    with TestClient(_make_app(monkeypatch)) as client:
        default_response = client.post("/api/assistants/search")
        offset_response = client.post("/api/assistants/search", json={"offset": 1, "limit": 1})

    assert default_response.status_code == 200
    assert [assistant["assistant_id"] for assistant in default_response.json()] == ["lead_agent", "researcher", "writer"]
    assert offset_response.status_code == 200
    assert [assistant["assistant_id"] for assistant in offset_response.json()] == ["researcher"]