"""Test fixtures.

Every test runs against a throwaway SQLite file in a tmp_path, never the real
data directory. The environment has to be set before lembas.config is imported,
because Settings is a cached singleton read at import time.
"""

from __future__ import annotations

import os
import tempfile
from collections.abc import Iterator
from pathlib import Path

import pytest

# Must happen before any lembas import.
_TMP = tempfile.mkdtemp(prefix="lembas-tests-")
os.environ.update(
    {
        "LEMBAS_SECRET_KEY": "test-secret-key-not-for-real-use",
        "LEMBAS_DATA_DIR": _TMP,
        "LEMBAS_ALLOW_SIGNUP": "true",
        "LEMBAS_LOG_LEVEL": "warning",
    }
)

from fastapi.testclient import TestClient  # noqa: E402
from sqlalchemy.orm import Session  # noqa: E402

from lembas.config import settings  # noqa: E402
from lembas.db.base import Base  # noqa: E402
from lembas.db.session import get_engine, get_session_factory, reset_engine  # noqa: E402


@pytest.fixture(autouse=True)
def fresh_database(tmp_path: Path) -> Iterator[None]:
    """Point the engine at a per-test database and build the schema.

    reset_engine() is essential: the engine is a module-level singleton, so
    without it every test after the first would share the first one's file.
    """
    settings.data_dir = tmp_path
    reset_engine()
    settings.ensure_dirs()

    import lembas.db.models  # noqa: F401  (registers the tables)

    Base.metadata.create_all(bind=get_engine())
    yield
    reset_engine()


@pytest.fixture
def db() -> Iterator[Session]:
    session = get_session_factory()()
    try:
        yield session
    finally:
        session.close()


@pytest.fixture
def client() -> Iterator[TestClient]:
    from lembas.main import app

    # raise_server_exceptions=False so error-handler behaviour is exercised
    # rather than the exception propagating into the test.
    with TestClient(app, raise_server_exceptions=False) as test_client:
        yield test_client


@pytest.fixture
def registered(client: TestClient) -> dict[str, str]:
    """Register the first account. It becomes the administrator."""
    credentials = {
        "name": "Frodo",
        "email": "frodo@shire.test",
        "password": "speak-friend-and-enter",
    }
    response = client.post("/auth/register", data=credentials, follow_redirects=False)
    assert response.status_code == 303, response.text
    return credentials


@pytest.fixture
def user_id(db: Session, registered: dict[str, str]) -> str:
    """The registered user's id.

    Chats have a real foreign key to users and SQLite enforces it (the
    connect-time PRAGMA in db/session.py turns that on), so tests that build a
    Chat directly need a user that actually exists.
    """
    from sqlalchemy import select

    from lembas.db.models import User

    return db.scalar(select(User).where(User.email == registered["email"])).id