using System;
using System.Collections.Generic;
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.Net;
using Microsoft.Xna.Framework.Storage;

namespace Peanuts
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class PeanutsGame : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        private PeanutsModel model;
        private PeanutsView view;
        private PeanutsControl controller;
        
        private Texture2D uniformTexture;
        private SpriteFont font;

        private ICollection<Keys> keysDown;
        private ICollection<Keys> keysToCheck;

        public PeanutsGame()
        {
            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()
        {
            // set up view and projection for camera beyond bottom (y = 1.0) edge of playfield
            // and a little above the field (should really ask the model about its size instead
            // of hard-coding this)

            Matrix viewMatrix = Matrix.CreateLookAt(new Vector3(0.5f, 3.0f, -2.0f),
                                             new Vector3(0.5f, 0.0f, 0.0f),
                                             new Vector3(0.0f, 0.0f, -1.0f));

            float aspect = (float)Window.ClientBounds.Width / (float)Window.ClientBounds.Height;

            // set up perspective projection with 45 degree field of view and enough depth
            // to get everything in our scene

            Matrix projectionMatrix = Matrix.CreatePerspectiveFieldOfView((float)Math.PI / 6, aspect, 0.1f, 10.0f);

            // set up effect with the above view and projection, and with directional light aimed from over
            // player's right shoulder

            BasicEffect effect = new BasicEffect(GraphicsDevice, null);
            effect.World = Matrix.Identity;
            effect.View = viewMatrix;
            effect.Projection = projectionMatrix;
            effect.VertexColorEnabled = true;
            effect.LightingEnabled = true;
            effect.DirectionalLight0.Enabled = true;
            Vector3 lightDir = new Vector3(1.0f, -1.0f, 1.0f);
            lightDir.Normalize();
            effect.DirectionalLight0.Direction = lightDir;
            effect.DirectionalLight0.DiffuseColor = new Vector3(1.0f, 1.0f, 1.0f);
            effect.DirectionalLight0.SpecularColor = new Vector3(1.0f, 1.0f, 1.0f);

            model = new PeanutsModel();
            view = new PeanutsView(model, effect, GraphicsDevice);
            controller = new PeanutsControl();

            // set up event handling

            controller.Climb += new PeanutsControl.ClimbHandler(model.ClimbPlayer);

            keysDown = new HashSet<Keys>();
            keysToCheck = new HashSet<Keys>();
            keysToCheck.Add(Keys.Space);

            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);

            uniformTexture = Content.Load<Texture2D>("blank");
            font = Content.Load<SpriteFont>("Arial");
            view.SetFont(font);
        }

        /// <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();

            // check keys that we always care about the state of

            KeyboardState kb = Keyboard.GetState();
            int dx = 0;
            int dy = 0;
            if (kb.IsKeyDown(Keys.Up))
            {
                   dy = -1;
            }
            if (kb.IsKeyDown(Keys.Down))
            {
                dy = 1;
            }
            if (kb.IsKeyDown(Keys.Left))
            {
                   dx = -1;
            }
            if (kb.IsKeyDown(Keys.Right))
            {
                dx = 1;
            }
            model.MovePlayer(dx, dy);

            // check keys that we only care about when they are first pressed

            foreach (Keys k in keysToCheck)
            {
                if (kb.IsKeyDown(k))
                {
                    if (!keysDown.Contains(k))
                    {
                        // key is down, wasn't down before
                        keysDown.Add(k);
                        controller.keyPressed(k);
                    }
                }
            }

            // update the keys that are down

            ICollection<Keys> upKeys = new HashSet<Keys>();
            foreach (Keys k in keysDown)
            {
                if (kb.IsKeyUp(k))
                {
                    upKeys.Add(k);
                    // controller.keyReleased(k);
                }
            }
            foreach (Keys k in upKeys)
            {
                keysDown.Remove(k);
            }

            // update the model

            model.Update();

            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)
        {
            graphics.GraphicsDevice.Clear(Color.CornflowerBlue);

            view.Draw(); 

            base.Draw(gameTime);
        }
    }
}