QuickPlay/QuickPlay/Interfaces.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

// MPD client abstractions and simplifications
namespace QuickPlay
{
    /// <summary>
    /// Simplified abstraction of possible players. Only methods needed are included.
    ///
    /// That means that the interface may be extended in the future, which is sad.
    /// </summary>
    public interface IPlayer
    {
        public enum PlayerStatus
        {
            Disconnected, Playing, Stopped
        }
        Dictionary<string, IPlayable> Songs { get; }
        string PlayerName { get; }
        Task Play(IPlayable playable);
        float CurrentProgress { get; }
        PlayerStatus Status { get; }
        Task SetReasonableOptions();
        /// <summary>
        /// Attach to the real player.
        /// 
        /// Since this operation can be asynchronous, we cannot put it in th 
        /// constructor. And this allows for some tweaks before connecting. 
        /// </summary>
        /// <returns></returns>
        Task ConnectAsync();
    }
    /// <summary>
    /// A simple dataclass to hold auxiliary data of the Playable objects.
    /// </summary>
    // This is not really an interface, but since it is a dataclass, I treat it
    // more as a part of interface, so it belongs to this file.

    // Also, in order not to need boilerplate code, this should be semantically
    // treated as immutable even though it's not.
    public class PlayableMetadata
    {
        public TimeSpan usualPlayingTime;
        public string filePath;
    }

    public interface IPlayable
    {
        string Identifier { get; }
        PlayableMetadata Metadata { get; }
    }
    interface ILayoutStrategy
    {
        List<IPlayable> LayOut(ICollection<IPlayable> playables);
    }

    public class CannotConnectException: Exception
    {
        public CannotConnectException(string msg, Exception e) : base(msg, e) { }
        public CannotConnectException(string msg) : base(msg) { }
        public CannotConnectException() : base() { }
    }

}