// Marble Jar class implementation
//
// Dave Reed        davereed@creighton.edu
//////////////////////////////////////////////////////////////////

#include "Die.h"
#include "MarbleJar.h"

MarbleJar::MarbleJar(int black, int white)
// precondition : black >= 0, white >= 0
// postcondition: numBlack = black, numWhite = white
{
    numBlack = black;
    numWhite = white;
}

Color MarbleJar::DrawMarble()
// precondition : jar is not empty (numBlack+numWhite > 0)
// postcondition: draws a random marble and returns its color
//                (either BLACK OR WHITE).  As a side effect,
//                the corresponding color count is decremented.
{
    Die myDie(numBlack+numWhite);
    if (myDie.Roll() <= numBlack) {
        numBlack--;
        return BLACK;
    }
    else {
        numWhite--;
        return WHITE;
    }
}

void MarbleJar::AddMarble(Color marble)
// precondition : marble == BLACK or WHITE
// postcondition: adds a marble of the specified color to the jar,
//                incrementing the color count.
{
    if (marble == BLACK) {
        numBlack++;
    }
    else {
        numWhite++;
    }
}

bool MarbleJar::IsEmpty()
// precondition : jar contains numBlack and numWhite marbles
// postcondition: returns true if jar is empty (no marbles)
{    
    return (numBlack + numWhite == 0);
}