/*!
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
import type { Virtualizer } from "@tanstack/react-virtual";

type VirtualizerInstance = Virtualizer<HTMLDivElement, Element>;

type ScrollToTopOptions = {
  element: HTMLElement;
  virtualizer: VirtualizerInstance;
};

type ScrollToBottomOptions = {
  element: HTMLElement;
  virtualizer: VirtualizerInstance;
};

/**
 * Scroll to the top of the list
 */
export const scrollToTop = ({ element, virtualizer }: ScrollToTopOptions): void => {
  virtualizer.scrollToOffset(0);
  element.scrollTop = 0;
};

/**
 * Scroll to the bottom of the list
 */
export const scrollToBottom = ({ element, virtualizer }: ScrollToBottomOptions): void => {
  const totalSize = virtualizer.getTotalSize();
  const clientHeight = element.clientHeight || 0;
  const offset = Math.max(0, totalSize - clientHeight);

  virtualizer.scrollToOffset(offset);
  element.scrollTop = offset;
};
