from __future__ import annotations

from collections.abc import Iterator

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient
from sqlalchemy import create_engine
from sqlalchemy.engine import Engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import StaticPool

from config.database import Base
from dependencies import get_unit_of_work
from routes.dashboard import router as dashboard_router
from routes.projects import router as projects_router
from routes.scenarios import router as scenarios_router
from services.unit_of_work import UnitOfWork


@pytest.fixture()
def engine() -> Iterator[Engine]:
    engine = create_engine(
        "sqlite+pysqlite:///:memory:",
        future=True,
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(bind=engine)
    try:
        yield engine
    finally:
        Base.metadata.drop_all(bind=engine)
        engine.dispose()


@pytest.fixture()
def session_factory(engine: Engine) -> Iterator[sessionmaker]:
    testing_session = sessionmaker(
        bind=engine, expire_on_commit=False, future=True)
    yield testing_session


@pytest.fixture()
def client(session_factory: sessionmaker) -> Iterator[TestClient]:
    app = FastAPI()
    app.include_router(dashboard_router)
    app.include_router(projects_router)
    app.include_router(scenarios_router)

    def _override_uow() -> Iterator[UnitOfWork]:
        with UnitOfWork(session_factory=session_factory) as uow:
            yield uow

    app.dependency_overrides[get_unit_of_work] = _override_uow

    test_client = TestClient(app)
    try:
        yield test_client
    finally:
        test_client.close()


class TestDashboardRoute:
    def test_renders_empty_state(self, client: TestClient) -> None:
        response = client.get("/")
        assert response.status_code == 200
        html = response.text

        assert "No recent projects" in html
        assert "No simulation runs yet" in html
        assert "All scenarios look good" in html
        assert "—" in html  # Last data import placeholder