pokemon-cmd/src/main/java/storage/Inventory.java

package storage;

import items.*;

import java.util.*;

/**
 * This class represents a pokemon trainer's inventory
 */
public class Inventory {
    public static final Scanner in = new Scanner(System.in);
    private final Map<Item, Integer> items;

    /**
     * Initializes a new empty inventory
     */
    public Inventory() {
        this.items = new HashMap<>();
    }

    /**
     * Adds a new item to the inventory
     *
     * <p>If the inventory already contains the item, the amount will be added to the existing amount.</p>
     *
     * @param item <p>The item to be added to the inventory</p>
     * @param amount <p>The amount of the item to add</p>
     */
    public void addItem(Item item, Integer amount) {
        if (items.get(item) != null) {
            amount += items.get(item);
        }
        items.put(item, amount);
    }

    /**
     * Gets all available poke balls from the inventory
     * @return <p>A list of poke balls</p>
     */
    public List<AbstractPokeBall> getPokeBalls() {
        List<AbstractPokeBall> pokeBalls = new ArrayList<>();
        for (Item item : items.keySet()) {
            if (AbstractPokeBall.class.isAssignableFrom(item.getClass()) && items.get(item) > 0) {
                pokeBalls.add((AbstractPokeBall) item);
            }
        }
        return pokeBalls;
    }

    /**
     * Gets all available potions from the inventory
     * @return <p>A list of potions</p>
     */
    public List<AbstractPotion> getPotions() {
        List<AbstractPotion> potions = new ArrayList<>();
        for (Item item : items.keySet()) {
            if (AbstractPotion.class.isAssignableFrom(item.getClass()) && items.get(item) > 0) {
                potions.add((AbstractPotion) item);
            }
        }
        return potions;
    }

    /**
     * Prints out information about available poke balls
     */
    public void availablePokeBalls() {
        System.out.println("You may choose from these items:");
        List<AbstractPokeBall> pokeBalls = getPokeBalls();
        for (int i = 0; i < pokeBalls.size(); i++) {
            System.out.printf("%d: (%d) %s%n", i + 1, items.get(pokeBalls.get(i)), pokeBalls.get(i));
        }
        System.out.print(">");
    }

    /**
     * Prints out information about available potions
     */
    public void availablePotions() {
        System.out.println("You may choose from these items:");
        List<AbstractPotion> potionList = getPotions();
        for (int i = 0; i < potionList.size(); i++) {
            System.out.printf("%d: (%d) %s%n", i + 1, items.get(potionList.get(i)), potionList.get(i));
        }
        System.out.print(">");
    }

    /**
     * Gets a potion according to the user's input
     * @return <p>The potion the user chose, or null on invalid choice</p>
     */
    public AbstractPotion getChosenPotion() {
        List<AbstractPotion> potions = getPotions();
        if (in.hasNextInt()) {
            int choice = in.nextInt() - 1;
            if (choice >= 0 && choice < potions.size()) {
                in.nextLine();
                return potions.get(choice);
            }
        } else {
            in.nextLine();
        }
        return null;
    }

    /**
     * Gets a poke ball according to the user's input
     * @return <p>The poke ball the user chose, or null on invalid choice</p>
     */
    public AbstractPokeBall getChosenPokeBall() {
        List<AbstractPokeBall> pokeBalls = getPokeBalls();
        if (in.hasNextInt()) {
            int choice = in.nextInt() - 1;
            if (choice >= 0 && choice < pokeBalls.size()) {
                in.nextLine();
                return pokeBalls.get(choice);
            }
        } else {
            in.nextLine();
        }
        return null;
    }

    /**
     * Gets a save-able string containing all non-empty items in the inventory
     * @return <p>A save string Name;Amount</p>
     */
    public String getSaveString() {
        StringBuilder saveString = new StringBuilder();
        for (Item item : items.keySet()) {
            saveString.append(item.saveString()).append(";").append(items.get(item));
            saveString.append("\n");
        }
        return saveString.toString();
    }
}