#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <string>
#ifndef ENTITY_H
#define ENTITY_H

class entity
{
      public:
      entity(std::string imagefile,int startingx,int startingy){xpos=startingx;ypos=startingy;img=IMG_Load(imagefile.c_str());}
      bool movex(int xvel,int xmax,int xmin)
      {
           xpos+=xvel;
          
           if(xpos>xmax||xpos<xmin){
           xpos-=xvel;
           return false;
           }
           return true;
      }
      bool movey(int yvel,int ymax,int ymin)
      {
           ypos+=yvel;
           if(ypos>ymax||ypos<ymin){
           ypos-=yvel;
           return false;
           }
           return true;
      }
      void draw(SDL_Surface* screen)
      {
           SDL_Rect dest;
           dest.x=xpos;
           dest.y=ypos;
           SDL_BlitSurface(img,NULL,screen,&dest);
      }
      
      
      void setx(int x)
      {
           xpos=x;
      }
      void sety(int y)
      {
           ypos=y;
      }
      int getx()
      {
          return xpos;
      }
      int gety()
      {
          return ypos;
      }
      int getw()
      {
          return img->w;
      }
      int geth()
      {
          return img->h;
      }
      SDL_Surface* getsurface()
      {
         return img;
      }
      private:
              int xpos;
              int ypos;
              SDL_Surface* img;
};
#endif

#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <SDL/SDL_collide.h>
#include <windows.h>
#include "entity.h"
int SCREEN_W=628;//width of window
int SCREEN_H=348;//height of window
int xvel=1;//xvel of ball
int yvel=0;//yvel of ball
int paddleyvel=1;//how fast paddle goes
int leftgoal=0;//score of left player
int rightgoal=0;//score of right player
char windowtitle[100];
entity ball("pongball.bmp",SCREEN_W/2,SCREEN_H/2);// The ball
entity lpaddle("paddle.bmp",100,SCREEN_H/2);// The left paddle
entity rpaddle("paddle.bmp",SCREEN_W-100,SCREEN_H/2);//The right paddle
entity line("line.bmp",SCREEN_W/2,10);//The line in the middle
Uint8* keys;//used to check for keys
void initgame()
{
     SDL_Init(SDL_INIT_VIDEO);
     SDL_SetVideoMode(SCREEN_W,SCREEN_H,0,SDL_HWSURFACE|SDL_DOUBLEBUF);
     
}

void moveball() //check for collision against walls and paddles
{
     if(SDL_BoundingCollide(ball.getsurface(),ball.getx(),ball.gety(),lpaddle.getsurface(),lpaddle.getx(),lpaddle.gety()))
     {
     xvel=-xvel;
    
     }
     
     if(SDL_BoundingCollide(ball.getsurface(),ball.getx(),ball.gety(),rpaddle.getsurface(),rpaddle.getx(),rpaddle.gety()))
     xvel=-xvel;
     
     if(!ball.movex(xvel,SCREEN_W-20,0))
     xvel=-xvel;
     
     if(!ball.movey(yvel,SCREEN_H-20,0))
     yvel=-yvel;
     
     if(yvel>2)//make sure ball does not go so fast that it is impossible to hit
     yvel--;
     
     if(yvel<-2)
     yvel++;
}
void drawstuff()// draw the ball, the paddles, and the line in the middle, and update the window title which has the score in it
{
     ball.draw(SDL_GetVideoSurface());
     lpaddle.draw(SDL_GetVideoSurface());
     rpaddle.draw(SDL_GetVideoSurface());
     line.draw(SDL_GetVideoSurface());
     sprintf(windowtitle,"My pong game! Left player: %i Right player: %i",leftgoal,rightgoal);
     SDL_WM_SetCaption(windowtitle,NULL);
}
void checkgoals()//check if someone scored
{
     if(ball.getx()<lpaddle.getx()-20) //if ball is to the left of the left paddle
     {
     rightgoal++;// increase score of right player
     MessageBox(NULL,"Right player scored!!","Score!",MB_OK);
     ball.setx(SCREEN_W/2);// put entities back to their defaults
     ball.sety(SCREEN_H/2);
     lpaddle.setx(100);
     lpaddle.sety(SCREEN_H/2);
     rpaddle.setx(SCREEN_W-100);
     rpaddle.sety(SCREEN_H/2);
     }
     if(ball.getx()>rpaddle.getx()+20)// if ball is to the right of the right paddle
     {
     leftgoal++;// increase score of left player
     MessageBox(NULL,"Left player scored!!","Score!",MB_OK);
     ball.setx(SCREEN_W/2);
     ball.sety(SCREEN_H/2);
     lpaddle.setx(100);
     lpaddle.sety(SCREEN_H/2);
     rpaddle.setx(SCREEN_W-100);
     rpaddle.sety(SCREEN_H/2);
     }
}
     
int main(int argc,char* argv[])
{
    
   
    initgame(); //init the window and game
    atexit(SDL_Quit);
    SDL_Event event;
   char tmp[3];//used for deubugging
    int done=0;
     while(done==0)
    {
       keys=SDL_GetKeyState(NULL);
       SDL_PollEvent(&event);
       if(event.type==SDL_QUIT)
       exit(0);
       else if(event.type==SDL_KEYDOWN)
       {
       
         if(keys[SDLK_UP])
         {
         rpaddle.movey(-paddleyvel,SCREEN_H,0);
          if(SDL_BoundingCollide(ball.getsurface(),ball.getx(),ball.gety(),rpaddle.getsurface(),rpaddle.getx(),rpaddle.gety()))//bounce against paddles at angle
          yvel++;
          }
       
         if(keys[SDLK_DOWN])
         {
         rpaddle.movey(paddleyvel,SCREEN_H-75,0);
         if(SDL_BoundingCollide(ball.getsurface(),ball.getx(),ball.gety(),rpaddle.getsurface(),rpaddle.getx(),rpaddle.gety()))
         yvel--;
         }
         
         if(keys[SDLK_w])
         {
         lpaddle.movey(-paddleyvel,SCREEN_H,0);
         if(SDL_BoundingCollide(ball.getsurface(),ball.getx(),ball.gety(),lpaddle.getsurface(),lpaddle.getx(),lpaddle.gety()))
         yvel++;
         }
         
         if(keys[SDLK_s])
         {
         lpaddle.movey(paddleyvel,SCREEN_H-75,0);
         if(SDL_BoundingCollide(ball.getsurface(),ball.getx(),ball.gety(),lpaddle.getsurface(),lpaddle.getx(),lpaddle.gety()))
         yvel--;
         }
         
         if(keys[SDLK_y])//deubugging purpuses; prints the y velocity of ball
         {
          itoa(yvel,tmp,10);
          MessageBox(NULL,tmp,NULL,MB_OK);
          }
       
      }
       moveball(); //move the ball according to the velocities
       drawstuff();// draw the things
       checkgoals();//check if the ball is past a paddle
       SDL_Flip(SDL_GetVideoSurface());
       SDL_FillRect(SDL_GetVideoSurface(),NULL,0x000000);//put here because of some wierd bug with the paddles not getting updated
       SDL_Delay(2);//make game slower
    }
}