// case1: 스트림을 사용하지 않은 코드

public class Anagrams {
    public static void main(String[] args) throws IOException {
        File dictionary = new File(args[0]);
        int minGroupSize = Integer.parseInt(args[1]);
        Map<String, Set<String>> groups = new HashMap<>();
        try (Scanner s = new Scanner(dictionary)) {
            while (s.hasNext()) {
                String word = s.next();
                groups.computeIfAbsent(alphabetize(word),
                                       (unused) -> new TreeSet<>()).add(word);
            }
        }
        for (Set<String> group : groups.values())
            if (group.size() >= minGroupSize)
                System.out.println(group.size() + ": " + group);
    }
    private static String alphabetize(String s) {
        char[] a = s.toCharArray();
        Arrays.sort(a);
        return new String(a);
    }
}

// case2 스트림을 과도하 사용한 코드

public class Anagrams {
    public static void main(String[] args) throws IOException {
        Path dictionary = Paths.get(args[0]);
        int minGroupSize = Integer.parseInt(args[1]);
        try (Stream<String> words = Files.lines(dictionary)) {
            words.collect(
                groupingBy(word -> word.chars().sorted()
                                       .collect(StringBuilder::new,
                                                (sb, c) -> sb.append((char) c),
                                                StringBuilder::append).toString()))
                 .values().stream()
                 .filter(group -> group.size() >= minGroupSize)
                 .map(group -> group.size() + ": " + group)
                 .forEach(System.out::println);
        }
    }
}

// case3 적당한 절충안 코드

public class Anagrams {
    public static void main(String[] args) throws IOException {
        Path dictionary = Paths.get(args[0]);
        int minGroupSize = Integer.parseInt(args[1]);
        try (Stream<String> words = Files.lines(dictionary)) {
            words.collect(groupingBy(word -> alphabetize(word)))
                 .values().stream()
                 .filter(group -> group.size() >= minGroupSize)
                 .forEach(g -> System.out.println(g.size() + ": " + g));
        }
    }
    // alphabetize 메서드는 코드 45-1과 같다.
}