QuickPlay/QuickPlay/Configuration.cs

using System;
using System.IO;

namespace QuickPlay
{
#pragma warning disable CS0659 // This is basically an almost-singleton, which will never be put in any hash table.
    /// <summary>
    /// Application (global) configuration data class
    /// </summary>
    [Serializable]
    sealed class AppConfiguration
    {
        // XXX: All the fields need to be checked in overriden Equals method
        public readonly string playerConfigUrl;

        public static AppConfiguration loadSavedConfiguration()
        {
            throw new NotImplementedException();
        }

        public void saveConfiguration()
        {



            // Make sure that the configuration is same
            var newConfig = AppConfiguration.loadSavedConfiguration();
            if (this != newConfig) throw new InvalidDataException("Saved configuration is different from the supplied one.");
        }

        public PlayerConfiguration GetPlayerConfig()
        {
            // TODO: decide sensibly
            var cfgProvider = new CurlConfigurationProvider(playerConfigUrl);
            return cfgProvider.GetConfiguration();
        }

        // We want to compare by values.
        // It might actually be a bit more sensible to compare serialized
        // versions of the objects, but that seems unneccessarily hard.
        public override bool Equals(object obj)
        {
            var other = (AppConfiguration)obj;
            // These fields have to match...
            if (this.playerConfigUrl != other.playerConfigUrl) return false;
            return true;
        }
    }
#pragma warning restore CS0659

    /// <summary>
    /// Configuration of the player.
    /// 
    /// Contains details about connection, configured songs &c.
    /// </summary>
    class PlayerConfiguration
    {
        public static PlayerConfiguration FromFile(StreamReader reader)
        {
            return null; // FIXME: Implement
        }

        public IPlayer GetPlayer()
        {
            throw new NotImplementedException();
        }
    }

    interface IPlayerConfigurationProvider
    {
        PlayerConfiguration GetConfiguration();
    }

    sealed class CurlConfigurationProvider : IPlayerConfigurationProvider
    {
        readonly string configUrl;
        public CurlConfigurationProvider(string url)
        {
            configUrl = url;
        }
        public PlayerConfiguration GetConfiguration()
        {
            throw new NotImplementedException();
        }
    }

    sealed class FileConfigurationProvider : IPlayerConfigurationProvider
    {
        StreamReader reader;
        public FileConfigurationProvider(StreamReader reader)
        {
            this.reader = reader;
        }
        
        public FileConfigurationProvider(string filename)
        {
            this.reader = new StreamReader(filename);
        }
        public PlayerConfiguration GetConfiguration()
        {
            return PlayerConfiguration.FromFile(reader);
        }
    }

    sealed class DummyConfigurationProvider : IPlayerConfigurationProvider
    {
        public PlayerConfiguration GetConfiguration() => null;
    }
}