#include <cstdlib>
#include <ctime>

#include "GridDisplay.h"

class Beetle;

class Island
{
 private:
   Beetle* **location;  // Dynamic 2D array of pointers
   int rows;
   int cols;
   GridDisplay *gd;

 public:
   Island(GridDisplay *grid)
   {
    gd = grid;
    rows = 20;
    cols = 20;
    location = new Beetle**[rows];

    for ( int i = 0 ; i < rows ; i++ )
    {
       location[i] = new Beetle*[cols];
       for ( int j = 0 ; j < cols ; j++ )
       {
          location[i][j] = NULL;
       }
    }
   }

   int getRows()
   {
    return rows;
   }

   int getCols()
   {
    return cols;
   }
 
   bool isValid (int r, int c)
   {
    if (( r >= 0 && r < rows ) && ( c >= 0 && c < cols))
      return true;
    else
      return false;
   }
   
   bool isOccupied (int r, int c)
   {
    if ( location[r][c] == NULL )
      return false;
    else
      return true;
   }

   bool addBeetle (Beetle* b, int r, int c)
   {
    // verify to location is valid
    if ( isValid (r, c) == false )
      return false;
    // verify to location is empty
    if ( isOccupied (r, c) == true)
      return false;

    location[r][c] = b;
    gd->setChar (r,c,'@');
    return true;
   }

   bool moveBeetle (int currX, int currY, int nextX, int nextY)
   {
    // verify to/from locations are valid
    if ( isValid (currX, currY) == false )
      return false;
    if ( isValid (nextX, nextY) == false )
      return false;
    // verify a beetle exists at current location
    if ( isOccupied (currX, currY) == false)
      return false;
    // verify to location is empty
    if ( isOccupied (nextX, nextY) == true)
      return false;
    
    location[nextX][nextY] = location[currX][currY]; 
    location[currX][currY] = NULL; 
    gd->setChar (currX, currY, '.');
    gd->setChar (nextX, nextY, '@');
    return true;
   }
};


class Beetle
{
 private:
   Island* isl;
   int row;
   int col;
   int dayLastMoved;

 public:
   Beetle(Island *island)
   {
    isl = island;
 
    do  // randomly select a location until an empty location is found
    {
       row = rand() % island->getRows();   
       col = rand() % island->getCols();   
    }
    while ( island->addBeetle (this, row, col) == false );
   
    dayLastMoved = 0;
   }

   void move()
   {
    wander();
    //spawn();
   }

   void wander ()
   {
    int nextX = -999;
    int nextY = -999;
    int direction = rand() % 4;
    if ( direction == 0 ) // attempt to move left
    {
       nextX = row;
       nextY = col-1;
    }
    else if ( direction == 1 ) // attempt to move right
    {
       nextX = row;
       nextY = col+1;
    }
    else if ( direction == 2 ) // attempt to move up
    {
       nextX = row-1;
       nextY = col;
    }
    else if ( direction == 3 ) // attempt to move down
    {
       nextX = row+1;
       nextY = col;
    }

    if ( isl->moveBeetle ( row, col, nextX, nextY ) == true )
    {
       row = nextX;
       col = nextY;
    }
   }
};

int main ( int argc, char** argv)
{
 srand(time(NULL));

 GridDisplay gd;
 Island island(&gd);
 int day = 0;
 
 int bugCount = 20;
 Beetle** bugs;  // create an dynamic array of beetle pointers
 bugs = new Beetle*[bugCount];
 for (int i = 0 ; i < bugCount ; i++)
   bugs[i] = new Beetle (&island);

 // show the initial locations of the beetles
 gd.showGrid();

 // loop for 20 days
 while ( day < 20 )
 {
    day++;

    // move each beetle in the "bug array"
    for (int i = 0 ; i < bugCount ; i++)
    {
       bugs[i]->move();
    }

    // pause execution to allow "animation" to be seen
    gd.mySleep( 1000 );
    gd.showGrid();
 }

}