using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace BadGame
{
    public struct PlayerData
    {
        public Vector2 Position;
        public Vector2 Velocity;
        public int Health;
        public bool CanJump;
    }

    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        GraphicsDevice device;

        SpriteBatch spriteBatch;
        SpriteFont font;

        Texture2D backgroundTexture;
        Texture2D foregroundTexture;
        Texture2D playerTexture;
        Texture2D rect;

        int screenHeight;
        int screenWidth;

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

            IsFixedTimeStep = false;
        }

        protected override void Initialize()
        {
            graphics.PreferredBackBufferWidth = 800;
            graphics.PreferredBackBufferHeight = 400;
            graphics.IsFullScreen = false;
            graphics.ApplyChanges();

            Window.Title = "Terrible Game";

            base.Initialize();
        }

        public static PlayerData Save1 = new PlayerData();
        public static void BuildPlayerData()
        {
            Save1.Position = new Vector2(0, 312);
            Save1.Health = 100;
            Save1.Velocity = new Vector2((float)0.3, 0);
            Save1.CanJump = true;
        }

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

            backgroundTexture = Content.Load<Texture2D>("background");
            playerTexture = Content.Load<Texture2D>("player");
            foregroundTexture = Content.Load<Texture2D>("foreground");
            font = Content.Load<SpriteFont>("gameFont");

            rect = new Texture2D(GraphicsDevice, 1, 1);
            rect.SetData(new[] { Color.White });

            screenWidth = device.PresentationParameters.BackBufferWidth;
            screenHeight = device.PresentationParameters.BackBufferHeight;

            BuildPlayerData();
        }

        protected override void UnloadContent()
        {

        }

        void CollisionDetection()
        {
            Rectangle player = new Rectangle((int)Save1.Position.X, (int)Save1.Position.Y, 28, 28);
            Rectangle level = new Rectangle(0, 340, 800, 61);
            Rectangle enemy1 = new Rectangle(150, 310, 10, 10);
            Rectangle enemy2 = new Rectangle(350, 310, 10, 10);
            Rectangle enemy3 = new Rectangle(650, 310, 10, 10);
            Rectangle enemy4 = new Rectangle(750, 310, 10, 10);

            if (player.Intersects(level))
            {
                Save1.Position.Y = 312;
            }
            if (player.Intersects(enemy1)) BuildPlayerData();
            if (player.Intersects(enemy2)) BuildPlayerData();
            if (player.Intersects(enemy3)) BuildPlayerData();
            if (player.Intersects(enemy4)) BuildPlayerData();

            if (Save1.Position.X > screenWidth - 28) Save1.Position.X = screenWidth - 28;
            if (Save1.Position.X < 0) Save1.Position.X = 0;
            if (Save1.Position.Y > screenHeight) Save1.Position.Y = screenHeight;
            if (Save1.Position.Y < 0) Save1.Position.Y = 0;
        }

        private const float gravity = 1f;

        void Gravity()
        {
            Save1.Velocity.Y += gravity;
            Save1.Position.Y += Save1.Velocity.Y;

            if (Save1.Position.Y >= 312)
            {
                Save1.Velocity.Y = 0;
                Save1.CanJump = true;
            }

        }

        void Jump()
        {
            if (!Save1.CanJump) return;
            Save1.Velocity.Y -= 15;
            Save1.CanJump = false;
        }

        protected override void Update(GameTime gameTime)
        {

            KeyboardState keyboard = Keyboard.GetState();
            Vector2 input = Vector2.Zero;
            double elapsedTime = gameTime.ElapsedGameTime.TotalMilliseconds;
            double distance = (Save1.Velocity.X*elapsedTime);

            if (keyboard.IsKeyDown(Keys.W)) Jump();
            if (keyboard.IsKeyDown(Keys.A)) input.X -= 1;
            if (keyboard.IsKeyDown(Keys.S)) input.Y += 1;
            if (keyboard.IsKeyDown(Keys.D)) input.X += 1;

            if (input != Vector2.Zero)
            {
                input.Normalize();
                Save1.Position += input * (float)(distance);
            }

            Gravity();
            CollisionDetection();

            base.Update(gameTime);
        }

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

            spriteBatch.Begin();
            DrawLevel();
            DrawText();
            spriteBatch.End();

            base.Draw(gameTime);

        }

        private void DrawText()
        {
            spriteBatch.DrawString(font, String.Format("Position: {0} Gravity: {1} Velocity: {2}", Save1.Position, gravity, Save1.Velocity.Y), new Vector2(0, 0), Color.White);
        }

        private void DrawLevel()
        {
            Rectangle screenRectangle = new Rectangle(0, 0, screenWidth, screenHeight);

            spriteBatch.Draw(backgroundTexture, screenRectangle, Color.White);
            spriteBatch.Draw(rect, new Rectangle(0, 340, 800, 61), Color.Green);
            spriteBatch.Draw(rect, new Rectangle(150, 310, 10, 10), Color.Black);
            spriteBatch.Draw(rect, new Rectangle(350, 310, 10, 10), Color.Black);
            spriteBatch.Draw(rect, new Rectangle(650, 310, 10, 10), Color.Black);
            spriteBatch.Draw(rect, new Rectangle(750, 310, 10, 10), Color.Black);
            DrawPlayer();
            spriteBatch.Draw(foregroundTexture, screenRectangle, Color.White);
        }

        private void DrawPlayer()
        {
            spriteBatch.Draw(playerTexture, Save1.Position, Color.White);
        }
    }
}