import pytest
from fastapi.testclient import TestClient
from unittest.mock import patch, AsyncMock
from backend.main import app

client = TestClient(app)


class TestHealthInfoEndpoints:
    """
    Check the availability of health/info endpoints 
    and the validity of the model configuration.
    """

    @pytest.mark.parametrize("route", ["/", "/info"])
    def test_health_info_returns_200(self, route) -> None:
        resp = client.get(route)
        assert resp.status_code == 200
    
    def test_info_models_config_valid(self) -> None:
        resp = client.get("/info")
        config = resp.json()["config"]
        assert "default_model" in config
        assert isinstance(config["available_models"], list)
        assert len(config["available_models"]) > 0
        assert config["default_model"] in config["available_models"]


class TestRunAgentEndpoint:
    """
    Checks /api/run: SSE response, default model, 
    validation and message generation.
    """

    def test_run_sse_contract(self, mock_agent_task) -> None:
        resp = client.post("/api/run", json={
            "query": "test",
            "model": "gpt-oss-120b"
        })
        assert resp.status_code == 200
        assert "text/event-stream" in resp.headers["content-type"]
        assert "data:" in resp.text
        assert "data: [DONE]" in resp.text


    def test_run_default_model_used_when_not_specified(self, mock_agent_task) -> None:
        from configs import DEFAULT_MODEL
        resp = client.post("/api/run", json={"query": "test"})
        assert resp.status_code == 200


    def test_run_missing_query_returns_422(self) -> None:
        resp = client.post("/api/run", json={"model": "gemini-2.5-flash"})
        assert resp.status_code == 422


    def test_run_single_message_no_history(self) -> None:
        from backend.routers.run_agent import build_messages, Query
        q = Query(query="test", model="gpt-oss-120b")
        messages = build_messages(q)
        assert len(messages) == 1
        assert messages[0] == {"role": "user", "content": "test"}


    def test_run_history_prepended_before_query(self) -> None:
        from backend.routers.run_agent import build_messages, Query, Message
        q = Query(
            query="a ďalej?",
            model="gpt-oss-120b",
            history=[
                Message(role="user", content="prvá otázka"),
                Message(role="assistant", content="prvá odpoveď"),
            ]
        )
        messages = build_messages(q)
        assert len(messages) == 3
        assert messages[0]["role"] == "user"
        assert messages[1]["role"] == "assistant"
        assert messages[2]["content"] == "a ďalej?"