/*
 * 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 CommonDataSource <T> implements IDataSource {
  private dataArray: T[] = []
  private listeners: DataChangeListener[] = []

  constructor(element: []) {
    this.dataArray = element
  }

  public getData(index: number) {
    return this.dataArray[index]
  }

  public totalCount(): number {
    return this.dataArray.length
  }

  public addData(index: number, data: T[]): void {
    this.dataArray = this.dataArray.concat(data)
    this.notifyDataAdd(index)
  }

  unregisterDataChangeListener(listener: DataChangeListener): void {
    const pos = this.listeners.indexOf(listener);
    if (pos >= 0) {
      this.listeners.splice(pos, 1);
    }
  }

  registerDataChangeListener(listener: DataChangeListener): void {
    if (this.listeners.indexOf(listener) < 0) {
      this.listeners.push(listener)
    }
  }

  notifyDataAdd(index: number): void {
    this.listeners.forEach((listener: DataChangeListener) => {
      listener.onDataAdd(index)
    })
  }

  reloadData() {
    this.listeners.forEach((listener)=>{
      listener.onDataReloaded()
    })
  }
}