using Chernobyl.Collections.Generic.Event;
using Chernobyl.DesignPatterns.Extension;
using Chernobyl.Game;
using Chernobyl.Graphics.Drawing;

namespace Chernobyl.Interface.Game.StateMachine
{
    /// <summary>
    /// An <see cref="IExtension{TExtended}"/> that, when attached to an
    /// <see cref="IGame"/>, displays itself when that <see cref="IGame"/> enters
    /// into a particular state (decided by the derived type).
    /// </summary>
    public abstract class StateScreen : Extension<IGame>
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="StateScreen"/> class.
        /// </summary>
        /// <param name="services">The root <see cref="IEventCollection{T}"/> 
        /// instance that gives and takes services.</param>
        public StateScreen(IEventCollection<object> services)
        {
            OnOffDrawable = new OnOffDrawable(services);
        }

        /// <summary>
        /// Attaches this extension to the passed in object so that is can be
        /// extended.
        /// </summary>
        /// <param name="extended">The object to extend.</param>
        protected abstract override void AttachTo(IGame extended);

        /// <summary>
        /// Removes this extension from an object so that it is no longer extended.
        /// </summary>
        /// <param name="extended">The object to remove the extension from.</param>
        protected abstract override void DetachFrom(IGame extended);

        /// <summary>
        /// The <see cref="IDrawable"/> that can be used to enable/disable
        /// rendering of the screen.
        /// </summary>
        protected OnOffDrawable OnOffDrawable { get; private set; }
    }
}