/*
 * Copyright (c) 2019 Hemanth Savarala.
 *
 * Licensed under the GNU General Public License v3
 *
 * This is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by
 *  the Free Software Foundation either version 3 of the License, or (at your option) any later version.
 *
 * This software 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 General Public License for more details.
 */

package code.name.monkey.retromusic.volume;

import android.database.ContentObserver;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Handler;

import androidx.annotation.NonNull;

public class AudioVolumeContentObserver extends ContentObserver {

    private final OnAudioVolumeChangedListener mListener;

    private final AudioManager mAudioManager;

    private final int mAudioStreamType;

    private float mLastVolume;

    AudioVolumeContentObserver(@NonNull Handler handler, @NonNull AudioManager audioManager,
                               int audioStreamType,
                               @NonNull OnAudioVolumeChangedListener listener) {

        super(handler);
        mAudioManager = audioManager;
        mAudioStreamType = audioStreamType;
        mListener = listener;
        mLastVolume = audioManager.getStreamVolume(mAudioStreamType);
    }

    /**
     * Depending on the handler this method may be executed on the UI thread
     */
    @Override
    public void onChange(boolean selfChange, Uri uri) {
        if (mAudioManager != null && mListener != null) {
            float maxVolume = mAudioManager.getStreamMaxVolume(mAudioStreamType);
            float currentVolume = mAudioManager.getStreamVolume(mAudioStreamType);
            if (currentVolume != mLastVolume) {
                mLastVolume = currentVolume;
                mListener.onAudioVolumeChanged(currentVolume, maxVolume);
            }
        }
    }

    @Override
    public boolean deliverSelfNotifications() {
        return super.deliverSelfNotifications();
    }
}