using System;
using FRB;
using FRB.GUI;
using FRB.Text;
using FRB.Particle;
using FRB.Collections;
using FRB.MSG;
using Microsoft.DirectX.DirectInput;

namespace GameName
{
   /// <summary>
   /// Summary description for GameData.
   /// </summary>
   public class GameData
   {
      #region reference to engine managers and data
      public GameForm form;
      public GuiData guiData;
      public InputManager inpMan;
      public SpriteManager sprMan;
      public TextManager textMan;
      public GuiManager guiMan;
      public Camera camera;
      public Cursor cursor;
      public Random random;
      #endregion

      // declare variables of class scope here

      SpriteArray asteroids;
      Sprite player;


      // we can increase or decrease this as we like
      float asteroidCreationFrequency;

      // we need this to measure the frequency
      long lastTimeAsteroidWasCreated;
      

      public void Initialize(GameForm form)
      {
         #region initialize engine managers and data
         this.form = form;
         guiData = new GuiData();
         sprMan = GameForm.sprMan;
         inpMan = GameForm.inpMan;
         textMan = GameForm.textMan;
         guiMan = GameForm.guiMan;
         camera = GameForm.camera;
         cursor = GameForm.cursor;
         random = GameForm.random;

         #endregion
         // this code is called only once when the program is executed

         // these arrays will act as "category" for our asteroids
         asteroids = new SpriteArray();

         // create the player.
         player = sprMan.AddSprite("redball.bmp");

         // distinguish the player by changing his color
         player.tintBlue = 255;
         player.tintGreen = 255;
         player.colorOperation = Microsoft.DirectX.Direct3D.TextureOperation.Add;

         // finally, move the player down a bit
         player.y = -10;


         asteroidCreationFrequency = 2f;  // one asteroid every 2 seconds


      }


      public void Activity()
      {
         // this code will be called once per frame.
 
         // arrows move player around, space will fire
         if(inpMan.KeyDown(Key.LeftArrow)) // left key will dominate if both left and right are down
            player.xVelocity = -20;
         else if(inpMan.KeyDown(Key.RightArrow))
            player.xVelocity = 20;
         else
            player.xVelocity = 0;

         if(inpMan.KeyPress(Key.Space))
            FireBullet(); // put in a separate method for organization

         if(TimeManager.SecondsSince(lastTimeAsteroidWasCreated) > asteroidCreationFrequency)
         {
            CreateAsteroid(); // again, in a separate method for organization
            lastTimeAsteroidWasCreated = TimeManager.currentTick;
         }
      }


      public void AfterFrameActivity()
      {
         // usually, the only code that goes here is text printing with the TextManager
         textMan.BeginDrawing();
         
         // this will verify that all of our Sprites are being created and we don't have any leaks

         textMan.Draw(sprMan.numOfRegularSprites.ToString());
      }


      public void FireBullet()
      {
         // create the bullet
         Sprite bullet = sprMan.AddSprite("redball.bmp");

         // scale it
         bullet.sclX = .2f;
         bullet.sclY = .7f;

         // position it
         bullet.x = player.x;
         bullet.y = player.y;

         // make it move upward
         bullet.yVelocity = 25;

         // give it custom behavior
         bullet.customFunctions += new customFunction(BulletBehavior);
      }


      public void CreateAsteroid()
      {
         // create the asteroid
         Sprite asteroid = sprMan.AddSprite("redball.bmp");

         // color it
         asteroid.colorOperation = Microsoft.DirectX.Direct3D.TextureOperation.Modulate;
         asteroid.tintRed = 100;
         asteroid.tintGreen = 255;

         // find the borders of the screen at z = 0 where the asteroid will be created
         float leftBorder = -1 * camera.xEdge * (- camera.z)/100.0f;
         float topBorder = camera.yEdge * (- camera.z)/ 100.0f;

         // position the asteroid on a random X position and just above the screen.
         asteroid.x = leftBorder + (float)random.NextDouble()* 2 * -leftBorder;
         asteroid.y = topBorder + asteroid.sclY;

         // make the asteroid fall
         asteroid.yVelocity = -15;

         // add the behavior so that it is removed from the screen when it moves too far down
         asteroid.customFunctions += new customFunction(AsteroidBehavior);

         // finally throw the asteroid in the asteroids SpriteArray for collision in the BulletBehavior
         asteroids.Add(asteroid);

      }


      public void BulletBehavior(Sprite bullet, SpriteManager sprMan)
      {
         // a few ways we could do collision.  Here's the most "low-level" way of doing it

         /* Usually when writing for loops that can remove an element from an Array, you want to loop backwards.
          * In this case, if an asteroid is destroyed, then we exit out of the method so we don't have to worry about
          * looping backwards.
          */
         for(int i = 0; i < asteroids.Count; i++)
         {
            if( Collisions.rectCollision( bullet, asteroids[i]))
            {
               /*
                * Remember, when we added our Sprite to the asteroids array, we used
                * the Add method which establishes a two-way relationship between the Sprite and the
                * containing SpriteArray.  That's why we simply can call sprMan.RemoveSprite and
                * the asteroid will be removed from its SpriteArrays.
                * How convenient!
                */
               sprMan.RemoveSprite(bullet);
               sprMan.RemoveSprite(asteroids[i]);

               return;
            }
         }

         /* we also want to check if the bullet is above the screen and remove it if so.
          */

         if( camera.IsYInView( bullet.y - bullet.sclY, bullet.z) == false)
         {
            // the bottom of the bullet is not in the screen.  Since bullets always move up, we can remove it
            sprMan.RemoveSprite(bullet);

         }


      }
   

      public void AsteroidBehavior(Sprite asteroid, SpriteManager sprMan)
      {
         if(asteroid.y < 0 &&  // need to make sure the asteroid is below the camera since it starts out of the screen
            camera.IsYInView( asteroid.y + asteroid.sclY, asteroid.z) == false)
         {
            // the asteroid is below the bottom of the screen.  Remove it
            sprMan.RemoveSprite(asteroid);

         }
   

      }
   
   }
}