using System;

namespace game
{
	class MainClass
	{
		private static DateTime dt = DateTime.Now;
		private static DateTime elapsedTime = DateTime.Now;
		
		private static int i = 0;
		private static int drawCount = 0;
		private static double dps = 0.0;
		
		// How many ticks to iterate through before you draw
		// Lower = Faster FPS
		private static int ticksPerDraw = 30000;
		
		/// <summary>
		/// Puts the cursor at the top so the screen may be overwritten
		/// </summary>
		private static void Clear()
		{
			Console.SetCursorPosition(0,0);
		}
		
		/// <summary>
		/// Returns a long with the number of ticks since last reset
		/// </summary>
		/// <returns>
		/// A <see cref="System.Int64"/>
		/// </returns>
		private static long GetTickCount()
		{
			DateTime now = DateTime.Now;
			
			long ticks = now.Ticks - dt.Ticks;
			
			return ticks;
		}
		
		/// <summary>
		/// Resets ticks
		/// </summary>
		private static void ResetTicks()
		{
			dt = DateTime.Now;
			i = 0;
		}
		
		/// <summary>
		/// Returns the number of Milliseconds since the game started
		/// </summary>
		/// <returns>
		/// A <see cref="System.Double"/>
		/// </returns>
		private static double GetMilliseconds()
		{
			DateTime check = DateTime.Now;
			TimeSpan ts = check - elapsedTime;
			
			return ts.TotalMilliseconds;
		}
		
		/// <summary>
		/// Returns the Framerate of the game
		/// </summary>
		/// <returns>
		/// A <see cref="System.Double"/>
		/// </returns>
		private static double CalculateFPS()
		{
			double seconds = GetMilliseconds();
			
			if(seconds > 0)
			{
				dps = drawCount / seconds;
			}
			
			return dps * 1000;
		}
		
		/// <summary>
		/// Draws.
		/// </summary>
		private static void Draw()
		{
			long ticks = GetTickCount();
			
			if(ticks > ticksPerDraw)
			{
				double fps = CalculateFPS();
				
				drawCount++;
				string draw = "\nGame Updates " + i + "\n" +
							  "Draw Count " + drawCount + "\n" +
							  "Frames per second " + fps;
			
				Console.Write(draw);
				
				ResetTicks();
			}
		}
		
		/// <summary>
		/// Updates the game info
		/// </summary>
		private static void UpdateGame()
		{
			i++;
		}
		
		/// <summary>
		/// Checks for keyboard input
		/// </summary>
		private static void CheckInput()
		{
		}
		
		/// <summary>
		/// Here be dragons
		/// </summary>
		/// <param name="args">
		/// A <see cref="System.String"/>
		/// </param>
		public static void Main()
		{
			Console.Clear();
			
			/**
			 * Game Loop
			 */
			bool running = true;
			while(running)
			{
				// Checks for keyboard input
				CheckInput();
				
				// Updates the game data
				UpdateGame();
				
				// Draws the game data
				Draw();
				
				// Resets the screen
				Clear();
			}
		}
	}
}