package uulm.teamname.marvelous.gamelibrary.entities;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;

/** Represents an inventory of 6 slots of {@link StoneType}s that can be manipulated.
 */
public class Inventory implements Iterable<StoneType> {
    /** The size of the inventory.
     */
    private final int size = 6;

    /** The content of the inventory.
     */
    private final HashSet<StoneType> content = new HashSet<>(size);

    /** Constructs a new {@link Inventory}.
     * @param content The starting content of the inventory.
     */
    public Inventory(ArrayList<StoneType> content) {
        if(content.size() > size) {
            throw new IllegalArgumentException("Attempted to construct an inventory with more than "+size+" initial stones.");
        }

        for(StoneType stone : content) {
            if(content.contains(stone)) {
                throw new IllegalArgumentException("Attempted to construct an inventory with duplicate entries.");
            }
            content.add(stone);
        }
    }

    /** Constructs a new empty {@link Inventory}.
     */
    public Inventory() {

    }

    /** Returns the number of free slots the inventory has.
     */
    public int getFreeSlots() {
        return size - content.size();
    }

    /** Checks if the inventory contains the given stone.
     * @param stone The {@link StoneType} to check for.
     */
    public boolean hasStone(StoneType stone) {
        return content.contains(stone);
    }

    /** Adds a stone to the inventory.
     * @param stone The {@link StoneType} to add.
     */
    public void addStone(StoneType stone) {
        if(content.contains(stone)) {
            throw new IllegalArgumentException("Attempted to add a duplicate stone to an inventory.");
        }
        if(content.size() == size) {
            throw new IllegalArgumentException("Attempted to add a stone to a full inventory.");
        }

        content.add(stone);
    }

    /** Removes a stone from the inventory.
     * @param stone The {@link StoneType} to remove.
     */
    public void removeStone(StoneType stone) {
        if(!content.contains(stone)) {
            throw new IllegalArgumentException("Attempted to remove a nonexistent stone from an inventory.");
        }

        content.remove(stone);
    }

    /** Iterates over the inventory.
     */
    @Override
    public Iterator<StoneType> iterator() {
        return content.iterator();
    }
}