/*************************************************************
 * File: game.cpp
 * Author: Br. Burton
 *
 * Description: Contains the implementations of the
 *  method bodies for the game class.
 *
 * Please DO NOT share this code with other students from
 *  other sections or other semesters. They may not receive
 *  the same code that you are receiving.
 *************************************************************/

#include "game.h"

#include <string>
#include "uiDraw.h"
#include "uiInteract.h"
#include "velocity.h"
#include "point.h"

#include <vector>
using namespace std;

#define OFF_SCREEN_BORDER_AMOUNT 5


/***************************************
 * GAME CONSTRUCTOR
 ***************************************/
Game :: Game(Point tl, Point br)
 : topLeft(tl), bottomRight(br), rifle(br)
{
   // Set up the initial conditions of the game
   score = 0;
   // TODO: Set your bird pointer to a good initial value (e.g., NULL)
   for ( int i = 0; i < 3; i++ )
   {
      bird[i] = NULL;
   }
}

/****************************************
 * GAME DESTRUCTOR
 ****************************************/
Game :: ~Game()
{
   // TODO: Check to see if there is currently a bird allocated
   //       and if so, delete it.
   for ( int i = 0; i < 3; i++ )
   {
      if (bird[i] != NULL) {
         delete bird[i];
         bird[i] = NULL;
      }
   }
}

/***************************************
 * GAME :: ADVANCE
 * advance the game one unit of time
 ***************************************/
void Game :: advance()
{
   advanceBullets();
   advanceBird();

   handleCollisions();
   cleanUpZombies();
}

/***************************************
 * GAME :: ADVANCE BULLETS
 * Go through each bullet and advance it.
 ***************************************/
void Game :: advanceBullets()
{
   // Move each of the bullets forward if it is alive
   for (int i = 0; i < bullets.size(); i++)
   {
      if (bullets[i].isAlive())
      {
         // this bullet is alive, so tell it to move forward
         bullets[i].advance();

         if (!isOnScreen(bullets[i].getPoint()))
         {
            // the bullet has left the screen
            bullets[i].kill();
         }

      }
   }
}

/**************************************************************************
 * GAME :: ADVANCE BIRD
 *
 * 1. If there is no bird, create one with some probability
 * 2. If there is a bird, and it's alive, advance it
 * 3. Check if the bird has gone of the screen, and if so, "kill" it
 **************************************************************************/
void Game :: advanceBird()
{
   for ( int i = 0; i < 3; i++ )
   {
      if (bird[i] == NULL)
      {
         // there is no bird right now, possibly create one

         // "resurrect" it will some random chance
         if (random(0, 30) == 0)
         {
            // create a new bird
            bird[i] = createBird();
         }
      }
      else
      {
         // we have a bird, make sure it's alive
         if (bird[i]->isAlive())
         {
            // move it forward
            bird[i]->advance();
            bird[i]->applyGravity();
            // check if the bird has gone off the screen
            if (!isOnScreen(bird[i]->getPoint()))
            {
               // We have missed the bird
               bird[i]->kill();
            }
         }
      }
   }

}

/**************************************************************************
 * GAME :: CREATE BIRD
 * Create a bird of a random type according to the rules of the game.
 **************************************************************************/
Bird* Game :: createBird()
{
   Bird* newBird = NULL;
   // TODO: Fill this in
   // Set random birds
    int ran = random(1,4);

    if(ran == 1)
    {
        newBird = new StandardBird();
    }

    else if(ran == 2)
    {
        newBird = new ToughBird();
    }
    else
    {
        newBird = new SacredBird();
    }

   return newBird;
}

/**************************************************************************
 * GAME :: IS ON SCREEN
 * Determines if a given point is on the screen.
 **************************************************************************/
bool Game :: isOnScreen(const Point & point)
{
   return (point.getX() >= topLeft.getX() - OFF_SCREEN_BORDER_AMOUNT
      && point.getX() <= bottomRight.getX() + OFF_SCREEN_BORDER_AMOUNT
      && point.getY() >= bottomRight.getY() - OFF_SCREEN_BORDER_AMOUNT
      && point.getY() <= topLeft.getY() + OFF_SCREEN_BORDER_AMOUNT);
}

/**************************************************************************
 * GAME :: HANDLE COLLISIONS
 * Check for a collision between a bird and a bullet.
 **************************************************************************/
void Game :: handleCollisions()
{
   // now check for a hit (if it is close enough to any live bullets)
   for (int i = 0; i < bullets.size(); i++)
   {
      if (bullets[i].isAlive())
      {
         // this bullet is alive, see if its too close

         // check if the bird is at this point (in case it was hit)
         for ( int j = 0; j < 3; j++ )
         {
            if (bird[j] != NULL && bird[j]->isAlive())
            {
               if (fabs(bullets[i].getPoint().getX() - bird[j]->getPoint().getX()) < CLOSE_ENOUGH
               && fabs(bullets[i].getPoint().getY() - bird[j]->getPoint().getY()) < CLOSE_ENOUGH)
               {
                  //we have a hit!
                  // hit the bird
                  int points = bird[j]->hit();
                  score += points;

                  // the bullet is dead as well
                  bullets[i].kill();
               }
            }
         }
      } // if bullet is alive

   } // for bullets
}

/**************************************************************************
 * GAME :: CLEAN UP ZOMBIES
 * Remove any dead objects (take bullets out of the list, deallocate bird)
 **************************************************************************/
void Game :: cleanUpZombies()
{
   // check for dead bird
   for ( int i = 0; i < 3; i++ )
   {
      if ( bird[i] != NULL && !bird[i]->isAlive() )
      {
         delete bird[i];
         bird[i] = NULL;
      }
   }

   // Look for dead bullets
   vector<Bullet>::iterator bulletIt = bullets.begin();
   while (bulletIt != bullets.end())
   {
      Bullet bullet = *bulletIt;
      // Asteroids Hint:
      // If we had a list of pointers, we would need this line instead:
      //Bullet* pBullet = *bulletIt;

      if (!bullet.isAlive())
      {
         // If we had a list of pointers, we would need to delete the memory here...


         // remove from list and advance
         bulletIt = bullets.erase(bulletIt);
      }
      else
      {
         bulletIt++; // advance
      }
   }

}

/***************************************
 * GAME :: HANDLE INPUT
 * accept input from the user
 ***************************************/
void Game :: handleInput(const Interface & ui)
{
   // Change the direction of the rifle
   if (ui.isLeft())
   {
      rifle.moveLeft();
   }

   if (ui.isRight())
   {
      rifle.moveRight();
   }

   // Check for "Spacebar
   if (ui.isSpace())
   {
      Bullet newBullet;
      newBullet.fire(rifle.getPoint(), rifle.getAngle());

      bullets.push_back(newBullet);
   }

}

/*********************************************
 * GAME :: DRAW
 * Draw everything on the screen
 *********************************************/
void Game :: draw(const Interface & ui)
{
   // draw the bird

   // TODO: Check if you have a valid bird and if it's alive
   // then call it's draw method
   for ( int i = 0; i < 3; i++ )
   {
      if (bird[i] != NULL && bird[i]->isAlive())
      {
         bird[i]->draw();
      }
   }


   // draw the rifle
   rifle.draw();

   // draw the bullets, if they are alive
   for (int i = 0; i < bullets.size(); i++)
   {
      if (bullets[i].isAlive())
      {
         bullets[i].draw();
      }
   }

   // Put the score on the screen
   Point scoreLocation;
   scoreLocation.setX(topLeft.getX() + 5);
   scoreLocation.setY(topLeft.getY() - 5);

   drawNumber(scoreLocation, score);

}