#region File Description
//-----------------------------------------------------------------------------
// Screen.cs
//
// Microsoft XNA Community Game Platform
// Copyright (C) Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------
#endregion

#region Using Statements
using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Input;
#endregion

namespace Marblets
{
	/// <summary>
	/// Screen represents a unit of rendering for the game, generally transitional point
	/// such as splash screens, selection screens and the actual game levels.
	/// </summary>
	public class Screen : DrawableGameComponent
	{
		private bool isMusicPlaying;
		private SoundEffectInstance cue;
		private SoundEntry backgroundMusic;
		private Texture2D backgroundTexture;
		private string backgroundImage;
		private RelativeSpriteBatch batch;

		/// <summary>
		/// Gets the sprite batch used for this screen
		/// </summary>
		/// <value>The sprite batch for this screen</value>
		public RelativeSpriteBatch SpriteBatch
		{
			get
			{
				return batch;
			}
		}

		/// <summary>
		/// Default constructor
		/// </summary>
		/// <param name="game">The game object</param>
		/// <param name="backgroundImage">The background image to use when this is 
		/// visible</param>
		/// <param name="backgroundMusic">The background music to play when this is 
		/// visible</param>
		public Screen(Game game, string backgroundImage, SoundEntry backgroundMusic)
			: base(game)
		{
			this.backgroundImage = backgroundImage;
			this.backgroundMusic = backgroundMusic;
		}

		/// <summary>
		/// Initializes the component.  Override to load any non-graphics resources and
		/// query for any required services.
		/// </summary>
		public override void Initialize()
		{
			base.Initialize();
		}

		/// <summary>
		/// Called when the DrawableGameComponent.Visible property changes.  Raises the
		/// DrawableGameComponent.VisibleChanged event.
		/// </summary>
		/// <param name="sender">The DrawableGameComponent.</param>
		/// <param name="args">Arguments to the DrawableGameComponent.VisibleChanged 
		/// event.</param>
		protected override void OnVisibleChanged(object sender, EventArgs args)
		{
			base.OnVisibleChanged(sender, args);
			if(!Visible)
			{
				ShutdownMusic();
			}
			else
			{
				StartMusic();
			}

		}

		private void ShutdownMusic()
		{
			if(isMusicPlaying)
			{
				Sound.StopMusic(cue);
				isMusicPlaying = false;
			}
		}

		private void StartMusic()
		{
			// TODO cue = Sound.PlayMusic(backgroundMusic);
			isMusicPlaying = true;
		}

		/// <summary>
		/// Tidies up the scene.
		/// </summary>
		public virtual void Shutdown()
		{
			ShutdownMusic();

			if(batch != null)
			{
				batch.Dispose();
				batch = null;
			}
		}

		/// <summary>
		/// Load your graphics content.
		/// </summary>
		protected override void LoadContent()
		{
			//Re-Create the Sprite Batch!
			IGraphicsDeviceService graphicsService =
                Game.Services.GetService(typeof(IGraphicsDeviceService))
				as IGraphicsDeviceService;

			batch = new RelativeSpriteBatch(graphicsService.GraphicsDevice);

			//Load content for any sub components
			if(!String.IsNullOrEmpty(backgroundImage))
			{
				backgroundTexture =
                    MarbletsGame.Content.Load<Texture2D>(backgroundImage);
			}
		}


		protected bool Clicked { get; private set; }
		private bool buttonWasDown = false;

		public override void Update(GameTime gameTime)
		{
			bool buttonDown = (Mouse.GetState().LeftButton == ButtonState.Pressed);
			Clicked = (buttonWasDown && !buttonDown);
			buttonWasDown = buttonDown;

			base.Update(gameTime);
			if(!isMusicPlaying)
				StartMusic();
		}

		/// <summary>
		/// Renders the screen. 
		/// </summary>
		public override void Draw(GameTime gameTime)
		{
			base.Draw(gameTime);

			if(!String.IsNullOrEmpty(backgroundImage))
			{
				SpriteBatch.Begin();
				SpriteBatch.Draw(backgroundTexture, Vector2.Zero, Color.White);
				SpriteBatch.End();
			}
		}
	}
}