import java.util.Random;
import java.util.List;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.awt.Color;
/**
 * Responsible for populating a field with foxes and rabbits.
 * It also knows the colors of the animals.
 *
 * @author Poul Henriksen
 * @version 2005.03.13
 */
public class PopulationGenerator
{

    // The probability that a fox will be created in any given grid position.
    private static final double FOX_CREATION_PROBABILITY = 0.02;
    // The probability that a rabbit will be created in any given grid position.
    private static final double RABBIT_CREATION_PROBABILITY = 0.08;

    // Mapping from classes to colors
    private Map colorMap;

    // The colors of the animals
    private Color FOX_COLOR = Color.BLUE;
    private Color RABBIT_COLOR = Color.ORANGE;


    /**
     * Constructor for objects of class PopulationGenerator
     */
    public PopulationGenerator()
    {
        colorMap = new HashMap();
        colorMap.put(Fox.class, FOX_COLOR);
        colorMap.put(Rabbit.class, RABBIT_COLOR);
    }

    /**
     * Populate a field with foxes and rabbits.
     * @param field The field to be populated.
     * @param animals The list of animals.
     */
    public void populate(Field field, List animals)
    {
        Random rand = new Random();
        field.clear();
        for(int row = 0; row < field.getDepth(); row++) {
            for(int col = 0; col < field.getWidth(); col++) {

                if(rand.nextDouble() <= FOX_CREATION_PROBABILITY) {
                    Fox fox = new Fox(true);
                    fox.setLocation(row, col);
                    animals.add(fox);
                    field.place(fox);
                }
                else if(rand.nextDouble() <= RABBIT_CREATION_PROBABILITY) {
                    Rabbit rabbit = new Rabbit(true);
                    rabbit.setLocation(row, col);
                    animals.add(rabbit);
                    field.place(rabbit);
                }
                // else leave the location empty.
            }
        }
        Collections.shuffle(animals);
    }

    public Map getColors() {
        return colorMap;
    }

}