/*
 * Copyright (c) 2024 Huawei Device Co., Ltd.
 * Licensed 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.
 */

export class CommentDataSource implements IDataSource {
  private elements: number[] = [];
  private listeners: Set<DataChangeListener>;

  constructor(elements: number[]) {
    this.elements = elements;
    this.listeners = new Set();
  }

  totalCount(): number {
    return this.elements.length;
  }

  getData(index: number): number {
    return this.elements[index];
  }

  registerDataChangeListener(listener: DataChangeListener): void {
    this.listeners.add(listener);
  }

  unregisterDataChangeListener(listener: DataChangeListener): void {
    this.listeners.delete(listener);
  }

  pushItem(item: number) {
    this.elements.push(item);
    this.listeners.forEach(listeners => {
      listeners.onDataAdd(this.elements.length);
    })
  }
}