using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;

///
/// A simple example to make object move where the mouse is clicked
///
namespace GotoLocation
{
#if WINDOWS || XBOX
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        static void Main(string[] args)
        {
            using (Game1 game = new Game1())
            {
                game.Run();
            }
        }
    }
#endif

    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        Vector2 direction = Vector2.Zero;
        Vector2 position = Vector2.Zero;
        float speed = 2f;

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";

            this.IsMouseVisible = true;
        }

        protected override void Initialize()
        {
            base.Initialize();
        }

        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);

            position.X = (graphics.PreferredBackBufferWidth / 2) - (Content.Load<Texture2D>("dot").Width / 2);
            position.Y = (graphics.PreferredBackBufferHeight / 2) - (Content.Load<Texture2D>("dot").Height / 2);

            direction = position;
        }

        protected override void UnloadContent()
        {
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();


            if (Mouse.GetState().LeftButton == ButtonState.Pressed)
            {
                direction = new Vector2(Mouse.GetState().X-(Content.Load<Texture2D>("dot").Width / 2), Mouse.GetState().Y-(Content.Load<Texture2D>("dot").Height / 2));
            }

            Vector2 move = Helper_Direction.MoveTowards(position, direction, speed);

            position.X += move.X;
            position.Y += move.Y;

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);

            spriteBatch.Begin();

            spriteBatch.Draw(Content.Load<Texture2D>("dot"), position, Color.White);

            spriteBatch.End();

            base.Draw(gameTime);
        }
    }

    public static class Helper_Direction
    {
        public static double FaceObject(Vector2 position, Vector2 target)
        {
            return (Math.Atan2(position.Y - target.Y, position.X - target.X) * (180 / Math.PI));
        }

        public static Vector2 MoveTowards(Vector2 position, Vector2 target, float speed)
        {
            double direction = (float)(Math.Atan2(target.Y - position.Y, target.X - position.X) * 180 / Math.PI);

            Vector2 move = new Vector2(0, 0);

            move.X = (float)Math.Cos(direction * Math.PI / 180) * speed;
            move.Y = (float)Math.Sin(direction * Math.PI / 180) * speed;

            return move;
        }
    }
}