using System;

namespace NAudio.CoreAudioApi.Interfaces
{
    /// <summary>
    /// interface to receive session related events
    /// </summary>
    public interface IAudioSessionEventsHandler
    {
        /// <summary>
        /// notification of volume changes including muting of audio session
        /// </summary>
        /// <param name="volume">the current volume</param>
        /// <param name="isMuted">the current mute state, true muted, false otherwise</param>
        void OnVolumeChanged(float volume, bool isMuted);

        /// <summary>
        /// notification of display name changed
        /// </summary>
        /// <param name="displayName">the current display name</param>
        void OnDisplayNameChanged(string displayName);

        /// <summary>
        /// notification of icon path changed
        /// </summary>
        /// <param name="iconPath">the current icon path</param>
        void OnIconPathChanged(string iconPath);

        /// <summary>
        /// notification of the client that the volume level of an audio channel in the session submix has changed
        /// </summary>
        /// <param name="channelCount">The channel count.</param>
        /// <param name="newVolumes">An array of volumnes cooresponding with each channel index.</param>
        /// <param name="channelIndex">The number of the channel whose volume level changed.</param>
        void OnChannelVolumeChanged(UInt32 channelCount, IntPtr newVolumes, UInt32 channelIndex);
        
        /// <summary>
        /// notification of the client that the grouping parameter for the session has changed
        /// </summary>
        /// <param name="groupingId">>The new grouping parameter for the session.</param>
        void OnGroupingParamChanged(ref Guid groupingId);

        /// <summary>
        /// notification of the client that the stream-activity state of the session has changed
        /// </summary>
        /// <param name="state">The new session state.</param>
        void OnStateChanged(AudioSessionState state);

        /// <summary>
        /// notification of the client that the session has been disconnected
        /// </summary>
        /// <param name="disconnectReason">The reason that the audio session was disconnected.</param>
        void OnSessionDisconnected(AudioSessionDisconnectReason disconnectReason);
    }
}