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 Blackjack {
    /// <summary>
    /// This is a game component that implements IUpdateable.
    /// </summary>
    public class StartScreen{

        MainGame game;
        KeyboardState lastKeystate;

        Texture2D titlesprite;
        Texture2D bgsplash;
        Texture2D pressstart;
        Texture2D blackoverlay;
        Rectangle overlayRect;
        Vector2 titlesprite_pos = new Vector2(0, 0);
        Vector2 pressstart_pos = new Vector2(0, 0);
        SoundEffect bgmusic;
        SoundEffectInstance sfxin;

        double closing_delay = 0.005f;
        double pressstart_fadedelay = 0.001f;
        bool pressstart_isfading = true;

        int pressstart_alpha = 255;
        int overlay_alpha = 0;
        bool screenclosing = false;

        public StartScreen(MainGame game) {
            this.game = game;
            titlesprite = game.Content.Load<Texture2D>("blackjack_logo");
            bgsplash = game.Content.Load<Texture2D>("bg_splash");
            pressstart = game.Content.Load<Texture2D>("press_enter_to_start");
            bgmusic = game.Content.Load<SoundEffect>("cybersoldier");
            sfxin = bgmusic.CreateInstance();
            sfxin.IsLooped = true;
            sfxin.Volume = 0.3f;
            sfxin.Play();
            titlesprite_pos = new Vector2((game.GraphicsDevice.Viewport.Width - titlesprite.Width) / 2, 100);
            pressstart_pos = new Vector2((game.GraphicsDevice.Viewport.Width - pressstart.Width) / 2, 280);

            blackoverlay = new Texture2D(game.GraphicsDevice, 1, 1);
            overlayRect = new Rectangle(0, 0, game.GraphicsDevice.Viewport.Width, game.GraphicsDevice.Viewport.Height);
            blackoverlay.SetData(new Color[] { Color.Black});
        }

        public void Unload() {
            sfxin.Stop();
            sfxin.Dispose();
            titlesprite.Dispose();
            bgsplash.Dispose();
            pressstart.Dispose();
            blackoverlay.Dispose();
        }

        private void CloseScreen() {
            screenclosing = true;
        }

        public void Update(GameTime gameTime) {
            KeyboardState keystate = Keyboard.GetState();
            if (keystate.IsKeyDown(Keys.Enter) && lastKeystate.IsKeyUp(Keys.Enter)) {
                //Start game.
                CloseScreen();
            }
            lastKeystate = keystate;

            if (pressstart_alpha <= 0) pressstart_isfading = false;
            else if (pressstart_alpha >= 255) pressstart_isfading = true;

            //Press start fade in/out animation.
            pressstart_fadedelay -= gameTime.ElapsedGameTime.TotalSeconds;
            if (pressstart_fadedelay <= 0) {
                pressstart_fadedelay = 0.001f;
                if (pressstart_isfading) {
                    pressstart_alpha -= 5;
                } else {
                    pressstart_alpha += 5;
                }
            }

            if (screenclosing) {
                closing_delay -= gameTime.ElapsedGameTime.TotalSeconds;
                if (closing_delay <= 0) {
                    closing_delay = 0.05f;
                    overlay_alpha += 25;
                }
                if (overlay_alpha > 255) {
                    Unload();
                    game.StartGame();
                }
            }

        }

        //override draw component.
        public void Draw(SpriteBatch spriteBatch) {

            spriteBatch.Draw(bgsplash, new Vector2(0, 0), Color.White);
            spriteBatch.Draw(titlesprite, titlesprite_pos, new Color(255, 255, 255, 255));
            spriteBatch.Draw(pressstart, pressstart_pos, new Color(255, 255, 255, pressstart_alpha));
            spriteBatch.Draw(blackoverlay, overlayRect, new Color(255, 255, 255, overlay_alpha));

        }

        public void StartGame() {

        }

    }
}