"""Anmeldung über server-seitige Sitzung im Cookie."""

from fastapi import APIRouter, Depends, HTTPException, Request, Response, status
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session

from ..config import get_settings
from ..database import get_db
from ..deps import get_current_user
from ..models import User
from ..schemas import PasswordChange, UserOut
from ..security import hash_password, verify_password
from ..services import sessions

router = APIRouter(prefix="/auth", tags=["auth"])


def _set_session_cookie(response: Response, raw_token: str) -> None:
    settings = get_settings()
    response.set_cookie(
        key=settings.cookie_name,
        value=raw_token,
        max_age=settings.session_ttl_days * 86400,
        httponly=True,
        secure=settings.cookie_secure,
        samesite=settings.cookie_samesite,
        path="/",
    )


@router.post("/login", response_model=UserOut)
def login(
    response: Response,
    request: Request,
    form: OAuth2PasswordRequestForm = Depends(),
    db: Session = Depends(get_db),
) -> User:
    user = db.query(User).filter(User.username == form.username).first()
    if user is None or not verify_password(form.password, user.password_hash):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Benutzername oder Passwort falsch",
        )
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Dieses Konto ist deaktiviert",
        )
    raw = sessions.create_session(db, user, request.headers.get("user-agent"))
    _set_session_cookie(response, raw)
    return user


@router.post("/logout", status_code=status.HTTP_204_NO_CONTENT)
def logout(request: Request, response: Response, db: Session = Depends(get_db)) -> None:
    token = request.cookies.get(get_settings().cookie_name, "")
    if token:
        sessions.revoke(db, token)
    response.delete_cookie(get_settings().cookie_name, path="/")


@router.get("/me", response_model=UserOut)
def me(current_user: User = Depends(get_current_user)) -> User:
    return current_user


@router.post("/change-password", response_model=UserOut)
def change_password(
    payload: PasswordChange,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> User:
    if not verify_password(payload.current_password, current_user.password_hash):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Aktuelles Passwort ist falsch",
        )
    current_user.password_hash = hash_password(payload.new_password)
    current_user.must_change_password = False
    db.commit()
    db.refresh(current_user)
    return current_user