//-----------------------------------------------------------------------------
// LoadingScreen.cs
//
// Display a screen to inform the player that their game is still responding,
// while loading content in the background.
//-----------------------------------------------------------------------------
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using RacingGame.Graphics;
using System.Threading.Tasks;
using RacingGame.Helpers;

namespace RacingGame.GameScreens
{
	/// <summary>
	/// Loading screen
	/// </summary>
	class LoadingScreen : IGameScreen
	{
		private const string loadingText = "Loading...";
		private int loadingTextWidth = TextureFont.GetTextWidth(loadingText);
		private string loadingStatus = "";
		public LoadingScreen()
		{
			//Setup the handler before we start the thread
			RacingGameManager.LoadEvent += new EventHandler<EventArgs>(LoadEvent);
		}
		/// <summary>
		/// Gather input on the loading screen and update it if progress has
		/// changed in loading the game.
		/// </summary>
		public void Update(GameTime gameTime)
		{
			if (RacingGameManager.LoadingTask == null)
			{
				RacingGameManager.LoadingTask = Task.Run(() =>
					RacingGameManager.LoadResources());
			}

			if (RacingGameManager.LoadingTask.IsCompleted)
			{
				if (RacingGameManager.LoadingTask.IsFaulted)
				{
					Log.Write("Content loading failed: " +
						RacingGameManager.LoadingTask.Exception);
				}
				// Proceed to next screen
			}
		}

		public void LoadEvent(object sender, EventArgs e)
		{
			loadingStatus = (string)sender;
		}
		/// <summary>
		/// Render loading screen
		/// </summary>
		public bool Render()
		{
			SpriteBatch textBatch = new SpriteBatch(BaseGame.Device);
			Vector2 position = new Vector2((BaseGame.Width / 2) - 50, (BaseGame.Height / 2) - 20);

			for (int i = 0; i < loadingText.Length; i++)
			{
				string charStr = new string(loadingText[i], 1);
				int charHeight = (int)(position.Y + 7 * Math.Abs(Math.Sin((i / 4f) + (-BaseGame.TotalTime * 3))));
				TextureFont.WriteText((int)position.X, charHeight, charStr, Color.Red);

				position.X += TextureFont.GetTextWidth(charStr);
			}

			TextureFont.WriteTextCentered(BaseGame.Width / 2, (int)position.Y + 40, loadingStatus);

			return RacingGameManager.ContentLoaded;
		}
	}
}