import logging

from fastapi import APIRouter, Depends, HTTPException, Response, status
from sqlalchemy import select
from sqlalchemy.orm import Session
from starlette.requests import Request

from app.core.rbac import require_permission
from app.db.database import get_db
from app.models.user import User
from app.repositories.rbac_repository import RbacRepository
from app.schemas.rbac import RoleCreate, RolePermissionUpdate, RoleResponse, RoleUpdate
from app.services.audit_service import sanitize, write_audit_log

logger = logging.getLogger(__name__)

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


def get_role_or_404(db: Session, role_id: int):
    role = RbacRepository.get_role_by_id(db, role_id)

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

    return role


def ensure_unique_role_name(db: Session, name: str, role_id: int | None = None) -> None:
    role = RbacRepository.get_role_by_name(db, name)
    if role is not None and role.id != role_id:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Rollenname ist bereits vergeben",
        )


def ensure_permission_ids_exist(db: Session, permission_ids: list[int]) -> None:
    permissions = RbacRepository.get_permissions_by_ids(db, permission_ids)
    if len(permissions) != len(set(permission_ids)):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Mindestens eine Berechtigung existiert nicht",
        )


@router.get("", response_model=list[RoleResponse])
@router.get("/", response_model=list[RoleResponse], include_in_schema=False)
def get_roles(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_permission("roles.read")),
):
    logger.info("roles.list", extra={"actor_user_id": current_user.id})
    return RbacRepository.get_roles(db)


@router.get("/{role_id}", response_model=RoleResponse)
def get_role(
    role_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_permission("roles.read")),
):
    logger.info(
        "roles.detail",
        extra={"actor_user_id": current_user.id, "target_role_id": role_id},
    )
    return get_role_or_404(db, role_id)


@router.post("", response_model=RoleResponse, status_code=status.HTTP_201_CREATED)
@router.post(
    "/",
    response_model=RoleResponse,
    status_code=status.HTTP_201_CREATED,
    include_in_schema=False,
)
def create_role(
    role: RoleCreate,
    request: Request,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_permission("roles.create")),
):
    ensure_unique_role_name(db, role.name)
    ensure_permission_ids_exist(db, role.permission_ids)

    logger.info("roles.create", extra={"actor_user_id": current_user.id})
    created_role = RbacRepository.create_role(db, role)
    write_audit_log(
        db,
        action="roles.create",
        entity_type="roles",
        entity_id=created_role.id,
        entity_label=created_role.name,
        actor=current_user,
        request=request,
        after_data=created_role,
    )
    return created_role


@router.put("/{role_id}", response_model=RoleResponse)
def update_role(
    role_id: int,
    role: RoleUpdate,
    request: Request,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_permission("roles.update")),
):
    db_role = get_role_or_404(db, role_id)
    before_data = sanitize(db_role)
    ensure_unique_role_name(db, role.name, role_id)
    ensure_permission_ids_exist(db, role.permission_ids)

    logger.info(
        "roles.update",
        extra={"actor_user_id": current_user.id, "target_role_id": role_id},
    )
    updated_role = RbacRepository.update_role(db, db_role, role)
    write_audit_log(
        db,
        action="roles.update",
        entity_type="roles",
        entity_id=updated_role.id,
        entity_label=updated_role.name,
        actor=current_user,
        request=request,
        before_data=before_data,
        after_data=updated_role,
    )
    return updated_role


@router.delete("/{role_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_role(
    role_id: int,
    request: Request,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_permission("roles.delete")),
):
    db_role = get_role_or_404(db, role_id)
    before_data = sanitize(db_role)
    entity_label = db_role.name
    if db_role.is_system:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Systemrollen dürfen nicht gelöscht werden",
        )

    assigned_user_id = db.scalar(select(User.id).where(User.role_id == role_id).limit(1))
    if assigned_user_id is not None:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Rolle ist Benutzern zugewiesen und kann nicht gelöscht werden",
        )

    logger.info(
        "roles.delete",
        extra={"actor_user_id": current_user.id, "target_role_id": role_id},
    )
    RbacRepository.delete_role(db, db_role)
    write_audit_log(
        db,
        action="roles.delete",
        entity_type="roles",
        entity_id=role_id,
        entity_label=entity_label,
        actor=current_user,
        request=request,
        before_data=before_data,
    )
    return Response(status_code=status.HTTP_204_NO_CONTENT)


@router.put("/{role_id}/permissions", response_model=RoleResponse)
def update_role_permissions(
    role_id: int,
    permission_update: RolePermissionUpdate,
    request: Request,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_permission("roles.assign")),
):
    db_role = get_role_or_404(db, role_id)
    before_data = sanitize(db_role)
    ensure_permission_ids_exist(db, permission_update.permission_ids)

    logger.info(
        "roles.permissions_update",
        extra={"actor_user_id": current_user.id, "target_role_id": role_id},
    )
    updated_role = RbacRepository.update_role_permissions(db, db_role, permission_update)
    write_audit_log(
        db,
        action="roles.permissions_update",
        entity_type="roles",
        entity_id=updated_role.id,
        entity_label=updated_role.name,
        actor=current_user,
        request=request,
        before_data=before_data,
        after_data=updated_role,
    )
    return updated_role