using System;
using Chernobyl.Collections.Generic.Event;
using Chernobyl.Graphics.Texture;
using Chernobyl.StateMachine;

namespace Chernobyl.Interface.Menu.Game
{
    /// <summary>
    /// The interface for a basic main menu in a video game. This type is used
    /// to help create main menus for video games.
    /// </summary>
    public class MainMenu : State
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="MainMenu"/> class.
        /// </summary>
        /// <param name="services">The instance that gives out services for use 
        /// by this type and takes services from this type for use by other 
        /// systems.</param>
        /// <param name="startButton">The button that starts the game that has 
        /// been selected or null if a default button should be created.</param>
        public MainMenu(IEventCollection<object> services, Button startButton)
        {
            StartButton = startButton;
            if(StartButton == null)
            {
                StartButton = new Button(services, new Texture2D(services, "data/images/play.tga"));
                StartButton.Translate(700, 100);
            }
            StartButton.OnUp += StartButtonOnUp;
        }

        /// <summary>
        /// The button that starts the game that has been selected.
        /// </summary>
        public Button StartButton { get; private set; }

        /// <summary>
        /// An event handler that is invoked when the 
        /// <see cref="MainMenu.StartButton"/> is let up. This method will 
        /// disable the <see cref="MainMenu.StartButton"/>.
        /// </summary>
        /// <param name="sender">The instance that generated the event.</param>
        /// <param name="e">The <see cref="EventArgs"/> instance containing the
        /// event data.</param>
        protected virtual void StartButtonOnUp(object sender, EventArgs e)
        {
            StartButton.ClickableRegion.Disable();
            StartButton.DrawableParent = null;
        }
    }
}