import logging

from fastapi import APIRouter, Depends, HTTPException, Response, status
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from sqlalchemy.orm import Session

from app.core.security import verify_access_token
from app.db.database import get_db
from app.models.user import User
from app.repositories.user_repository import UserRepository
from app.schemas.user import UserCreate, UserPasswordUpdate, UserResponse, UserUpdate

logger = logging.getLogger(__name__)

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

bearer_scheme = HTTPBearer(auto_error=False)


def get_current_user(
    credentials: HTTPAuthorizationCredentials | None = Depends(bearer_scheme),
    db: Session = Depends(get_db),
) -> User:
    if credentials is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Nicht authentifiziert",
            headers={"WWW-Authenticate": "Bearer"},
        )

    username = verify_access_token(credentials.credentials)
    user = UserRepository.get_by_username(db, username)

    if user is None or not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Nicht authentifiziert",
            headers={"WWW-Authenticate": "Bearer"},
        )

    return user


def require_role(*allowed_roles: str):
    def dependency(current_user: User = Depends(get_current_user)) -> User:
        if current_user.role not in allowed_roles:
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="Keine Berechtigung",
            )
        return current_user

    return dependency


def get_user_or_404(db: Session, user_id: int) -> User:
    db_user = UserRepository.get_by_id(db, user_id)

    if db_user is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Benutzer nicht gefunden",
        )

    return db_user


def raise_conflict(field: str) -> None:
    if field == "username":
        detail = "Benutzername ist bereits vergeben"
    else:
        detail = "E-Mail ist bereits vergeben"

    raise HTTPException(
        status_code=status.HTTP_409_CONFLICT,
        detail=detail,
    )


@router.get("", response_model=list[UserResponse])
@router.get("/", response_model=list[UserResponse], include_in_schema=False)
def get_users(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    logger.info("users.list", extra={"actor_user_id": current_user.id})
    return UserRepository.get_all(db)


@router.get("/{user_id}", response_model=UserResponse)
def get_user(
    user_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    logger.info(
        "users.detail",
        extra={"actor_user_id": current_user.id, "target_user_id": user_id},
    )
    return get_user_or_404(db, user_id)


@router.post("", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
@router.post(
    "/",
    response_model=UserResponse,
    status_code=status.HTTP_201_CREATED,
    include_in_schema=False,
)
def create_user(
    user: UserCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    conflict = UserRepository.find_conflict(
        db,
        username=user.username,
        email=str(user.email),
    )

    if conflict is not None:
        raise_conflict(conflict[0])

    logger.info("users.create", extra={"actor_user_id": current_user.id})
    return UserRepository.create(db, user)


@router.put("/{user_id}", response_model=UserResponse)
def update_user(
    user_id: int,
    user: UserUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    db_user = get_user_or_404(db, user_id)
    conflict = UserRepository.find_conflict(
        db,
        username=user.username,
        email=str(user.email),
        exclude_user_id=user_id,
    )

    if conflict is not None:
        raise_conflict(conflict[0])

    logger.info(
        "users.update",
        extra={"actor_user_id": current_user.id, "target_user_id": user_id},
    )
    return UserRepository.update(db, db_user, user)


@router.put("/{user_id}/password", response_model=UserResponse)
def update_user_password(
    user_id: int,
    password_update: UserPasswordUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    db_user = get_user_or_404(db, user_id)

    logger.info(
        "users.password_update",
        extra={"actor_user_id": current_user.id, "target_user_id": user_id},
    )
    return UserRepository.update_password(db, db_user, password_update)


@router.delete("/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_user(
    user_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    if current_user.id == user_id:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Der aktuell angemeldete Benutzer darf sich nicht selbst löschen",
        )

    db_user = get_user_or_404(db, user_id)

    logger.info(
        "users.delete",
        extra={"actor_user_id": current_user.id, "target_user_id": user_id},
    )
    UserRepository.delete(db, db_user)
    return Response(status_code=status.HTTP_204_NO_CONTENT)