import pytest
from fastapi.testclient import TestClient
from sqlalchemy import create_engine, event
from sqlalchemy.orm import Session
from sqlalchemy.pool import StaticPool

from app.db import Base, get_session
import app.models  # noqa: F401  ensures all ORM tables are registered on Base.metadata


@pytest.fixture
def db():
    engine = create_engine(
        "sqlite://", poolclass=StaticPool,
        connect_args={"check_same_thread": False},
    )

    # SQLite does not enforce foreign keys unless told to per-connection. Turn
    # enforcement on so the tests catch FK violations (missing cascades) the
    # same way Postgres would in production.
    @event.listens_for(engine, "connect")
    def _fk_pragma(dbapi_conn, _):
        cur = dbapi_conn.cursor()
        cur.execute("PRAGMA foreign_keys=ON")
        cur.close()

    Base.metadata.create_all(engine)
    with Session(engine) as session:
        yield session


@pytest.fixture
def client(db, monkeypatch):
    monkeypatch.setenv("FB_API_KEY", "test-key")
    from app.config import get_settings
    get_settings.cache_clear()
    from app.auth import hash_password
    monkeypatch.setenv("FB_GUI_PASSWORD_HASH", hash_password("geheim"))
    get_settings.cache_clear()
    from app.main import app

    def _override_get_session():
        yield db

    app.dependency_overrides[get_session] = _override_get_session
    with TestClient(app) as c:
        yield c
    app.dependency_overrides.clear()
    get_settings.cache_clear()


@pytest.fixture
def env_file(tmp_path):
    """Erzeugt eine .env-Datei im create_pod_finance.sh-Format (single-quoted
    KEY='value') mit einem initialen Passwort+Hash. Liefert (Pfad, Passwort)
    fuer Tests der Admin-Passwortaenderung (Ausbaustufe 4 Task 2), die die
    Laufzeit-.env-Lesung/-Schreibung ueber FB_ENV_FILE gegen eine tmp_path
    statt der echten Container-.env pruefen."""
    from app.auth import hash_password
    path = tmp_path / ".env"
    password = "geheim123"
    path.write_text(
        f"FB_PASSWORD='{password}'\n"
        f"FB_GUI_PASSWORD_HASH='{hash_password(password)}'\n"
    )
    return path, password


@pytest.fixture
def client_with_env_file(db, env_file, monkeypatch):
    """Wie `client`, aber der GUI-Passwort-Hash kommt NICHT aus der
    FB_GUI_PASSWORD_HASH-Umgebungsvariable, sondern wird zur Laufzeit aus der
    ueber FB_ENV_FILE referenzierten Datei gelesen (der Pfad, den
    change_password() in-place ueberschreibt)."""
    path, _password = env_file
    monkeypatch.setenv("FB_API_KEY", "test-key")
    monkeypatch.delenv("FB_GUI_PASSWORD_HASH", raising=False)
    monkeypatch.setenv("FB_ENV_FILE", str(path))
    from app.config import get_settings
    get_settings.cache_clear()
    from app.auth import _hash_cache
    _hash_cache.clear()
    from app.main import app

    def _override_get_session():
        yield db

    app.dependency_overrides[get_session] = _override_get_session
    with TestClient(app) as c:
        yield c, env_file[1]
    app.dependency_overrides.clear()
    get_settings.cache_clear()
    _hash_cache.clear()