/*
 * libmedia MeterWorkletNode
 *
 * 版权所有 (C) 2024 赵高兴
 * Copyright (C) 2024 Gaoxing Zhao
 *
 * 此文件是 libmedia 的一部分
 * This file is part of libmedia.
 * 
 * libmedia 是自由软件；您可以根据 GNU Lesser General Public License（GNU LGPL）3.1
 * 或任何其更新的版本条款重新分发或修改它
 * libmedia is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3.1 of the License, or (at your option) any later version.
 * 
 * libmedia 希望能够为您提供帮助，但不提供任何明示或暗示的担保，包括但不限于适销性或特定用途的保证
 * 您应自行承担使用 libmedia 的风险，并且需要遵守 GNU Lesser General Public License 中的条款和条件。
 * libmedia is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 */

import type { AudioWorkletNodeObserver } from '../base/AudioWorkletNodeBase'
import AudioWorkletNodeBase from '../base/AudioWorkletNodeBase'

import {
  NOTIFY,
  type RpcMessage
} from '@libmedia/common/network'

export interface MeterWorkletNodeObserver extends AudioWorkletNodeObserver {
  onAudioLevel: (audioLevel: number) => void
}
export default class MeterWorkletNode extends AudioWorkletNodeBase {

  declare protected observer: MeterWorkletNodeObserver

  private audioLevel: number

  constructor(context: AudioContext, observer: MeterWorkletNodeObserver, options: AudioWorkletNodeOptions = {}) {
    super(context, observer, 'meter-processor', options)
    this.audioLevel = 0

    this.audioWorkletNode.port.onmessage = (event) => {
      this.audioLevel = event.data
    }
    this.ipcPort.on(NOTIFY, (request: RpcMessage) => {
      switch (request.method) {
        case 'audioLevel':
          this.audioLevel = request.params.audioLevel
          this.observer.onAudioLevel(this.audioLevel)
          break
      }
    })
  }

  public getAudioLevel() {
    return this.audioLevel
  }
}