Discounts

import java.util.*;
import java.util.stream.*;
import java.io.*;

public class DiscountsTest {
    public static void main(String[] args) {
        Discounts discounts = new Discounts();
        int stores = discounts.readStores(System.in);
        System.out.println("Stores read: " + stores);
        System.out.println("=== By average discount ===");
        discounts.byAverageDiscount().forEach(System.out::println);
        System.out.println("=== By total discount ===");
        discounts.byTotalDiscount().forEach(System.out::println);
    }
}

class Price {
    private int discount;
    private int price;

    public Price (String discount, String price) {
        this.discount = Integer.parseInt(discount);
        this.price = Integer.parseInt(price);
    }

    public int getAbsolute () {
        return price - discount;
    }

    public double getAverage () {
        return ((price - discount) * 100) / price;
    }

    public String toString () {
        return String.format("%2d%% %d/%d\n", (int)getAverage(), discount, price);
    }
}

class Store {
    private String name;
    private List <Price> prices;

    public Store (String name, List <Price> prices) {
        this.name = name;
        this.prices = prices;
    }

    public int Absolute () {
        return prices.stream().mapToInt(price -> price.getAbsolute()).sum();
    }

    public double Average () {
        return prices.stream().mapToDouble(price -> price.getAverage()).average().orElse(0);
    }

    static Store fromString (String s) {
        List <Price> list = new ArrayList<> ();
        String [] parts = s.split("\\s++");
        IntStream.range(1, parts.length)
            .forEach(i -> {
                String [] newPart = parts[i].split(":");
                Price price = new Price (newPart[0], newPart[1]);
                list.add(price);
            });
        return new Store (parts[0], list);
    }

    public String getName () {
        return name;
    }

    public String toString () {
        StringBuilder builder = new StringBuilder ();
        builder.append(String.format("%s\nAverage discount: %.1f%%\nTotal discount: %d\n",
                                    name, Average(), Absolute()));
        prices.stream()
            .sorted(Comparator.comparing(Price::getAverage)
                            .thenComparing(Price::getAbsolute).reversed())
            .forEach(each -> builder.append(each));
        builder.setLength(builder.length() - 1);
        return builder.toString();
    }
}

class Discounts {
    private List <Store> list;

    public Discounts () {
        list = new ArrayList <> ();
    }

    public int readStores (InputStream inputStream) {
        BufferedReader reader = new BufferedReader (new InputStreamReader (inputStream));
        list = reader.lines()
                .map(Store::fromString)
                .collect(Collectors.toList());
        return list.size();
    }

    public List<Store> byAverageDiscount () {
        return list.stream()
                .sorted(Comparator.comparing(Store::Average).reversed()
                                  .thenComparing(Store::getName))
                .limit(3)
                .collect(Collectors.toList());
    }

    public List <Store> byTotalDiscount () {
        return list.stream()
                .sorted(Comparator.comparing(Store::Absolute)
                                    .thenComparing(Store::getName))
                .limit(3)
                .collect(Collectors.toList());
    }
}