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;

namespace AnimatedSprites
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        Texture2D texture;
        Vector2 position;
        float horizontalSpeed = 4;
        float verticalSpeed = 4;
        Point frameSize = new Point(32, 48);
        Point currentFrame = new Point(0, 0);
        Point sheetSize = new Point(4, 4);

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

        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            // TODO: Add your initialization logic here

            base.Initialize();
        }

        /// <summary>
        /// LoadContent will be called once per game and is the place to load
        /// all of your content.
        /// </summary>
        protected override void LoadContent()
        {
            // Create a new SpriteBatch, which can be used to draw textures.
            spriteBatch = new SpriteBatch(GraphicsDevice);
            texture = Content.Load<Texture2D>(@"Images\indy");
            // TODO: use this.Content to load your game content here
        }

        /// <summary>
        /// UnloadContent will be called once per game and is the place to unload
        /// all content.
        /// </summary>
        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            ++currentFrame.X;
            if (currentFrame.X >= sheetSize.X)
            {
                currentFrame.X = 0;
                ++currentFrame.Y;

                if (currentFrame.Y >= sheetSize.Y)
                {
                    currentFrame.Y = 0;
                }
            }

            position.X += horizontalSpeed;
            position.Y += verticalSpeed;
            if (position.X > Window.ClientBounds.Width - frameSize.X || position.X < 0)
            {
                horizontalSpeed *= -1;
            }
            if (position.Y > Window.ClientBounds.Height - frameSize.Y || position.Y < 0)
            {
                verticalSpeed *= -1;
            }


            base.Update(gameTime);
        }

        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.Black);

            spriteBatch.Begin(SpriteSortMode.FrontToBack, BlendState.AlphaBlend);

            spriteBatch.Draw(texture,
                                position,
                                new Rectangle(currentFrame.X * frameSize.X, currentFrame.Y * frameSize.Y, frameSize.X, frameSize.Y),
                                Color.White,
                                0,
                                Vector2.Zero,
                                1,
                                SpriteEffects.None,
                                0);

            spriteBatch.End();

            base.Draw(gameTime);
        }
    }
}