using System;
using Chernobyl.Creation;

namespace Chernobyl.Generation
{
    /// <summary>
    /// Represents a type is capable of playing sounds.
    /// </summary>
    public interface IPlayer : IDisposable
    {
        /// <summary>
        /// Start playing the audio.
        /// </summary>
        void Play();

        /// <summary>
        /// Stop playing the audio.
        /// </summary>
        void Stop();

        /// <summary>
        /// The current state of the sound being played.
        /// </summary>
        PlayerState State { get; }

        /// <summary>
        /// The current time in the stream from the start.
        /// </summary>
        TimeSpan Position { get; }

        /// <summary>
        /// The current location in the stream from the start in bytes.
        /// </summary>
        long BytePosition { get; }
    }

    /// <summary>
    /// The state of a sound player.
    /// </summary>
    public enum PlayerState
    {
        /// <summary>
        /// The sound was playing but is now paused.
        /// </summary>
        Paused,

        /// <summary>
        /// The sound is playing.
        /// </summary>
        Playing,

        /// <summary>
        /// The sound is not playing.
        /// </summary>
        Stopped
    }

    /// <summary>
    /// Initialization properties for the creation of an wave <see cref="IPlayer"/> through an
    /// <see cref="IWavePlayerFactory"/>.
    /// </summary>
    public class WavePlayerConfig
    {
        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="waveFunc">The method that produces the wave.</param>
        /// <param name="sampleRate">The rate in milliseconds at which a wave is sampled.</param>
        /// <param name="channels">The number of channels (speakers for example) to player the music
        /// from. For example, 1 is mono.</param>
        public WavePlayerConfig(Func<float> waveFunc, int sampleRate = 16000, int channels = 1)
        {
            WaveFunc = waveFunc;
            SampleRate = sampleRate;
            Channels = channels;
        }

        /// <summary>
        /// The method that produces the wave.
        /// </summary>
        public Func<float> WaveFunc { get; }

        /// <summary>
        /// The rate in milliseconds at which a wave is sampled.
        /// </summary>
        public int SampleRate { get; }

        /// <summary>
        /// The number of channels (speakers for example) to player the music from. For example, 1
        /// is mono.
        /// </summary>
        public int Channels { get; }
    }

    /// <summary>
    /// Creates an <see cref="IPlayer"/> capable of playing a wave.
    /// </summary>
    public interface IWavePlayerFactory : IFactory<WavePlayerConfig, IPlayer> {}
}