record Message(String type, String value) {}

Map<String, BlockingQueue<Message>> mailboxes =
    new ConcurrentHashMap<>();

BlockingQueue<Message> mailbox(String name) {
    return mailboxes.computeIfAbsent(
        name,
        _ -> new LinkedBlockingQueue<>()
    );
}

String rot13(String text) {
    var result = new StringBuilder();

    for (var character : text.toCharArray()) {
        if (character >= 'a' && character <= 'z')
            character = (char) ('a' + (character - 'a' + 13) % 26);
        else if (character >= 'A' && character <= 'Z')
            character = (char) ('A' + (character - 'A' + 13) % 26);

        result.append(character);
    }

    return result.toString();
}

void mediate(String from, String to) {
    try {
        while (true)
            mailbox(to).put(mailbox(from).take());
    } catch (InterruptedException _) {
        Thread.currentThread().interrupt();
    }
}

void runConsoleIn() {
    try {
        while (true) {
            var text = IO.readln();

            if (text == null)
                return;

            mailbox("consoleIn.outbox")
                .put(new Message("TEXT", text));
        }
    } catch (InterruptedException _) {
        Thread.currentThread().interrupt();
    }
}

void runRot13() {
    try {
        while (true) {
            var input = mailbox("rot13.inbox").take();
            var output = new Message("TEXT", rot13(input.value()));
            mailbox("rot13.outbox").put(output);
        }
    } catch (InterruptedException _) {
        Thread.currentThread().interrupt();
    }
}

void runConsoleOut() {
    try {
        while (true)
            IO.println(mailbox("consoleOut.inbox").take().value());
    } catch (InterruptedException _) {
        Thread.currentThread().interrupt();
    }
}

void main() throws InterruptedException {
    Thread.ofVirtual().start(this::runConsoleIn);
    Thread.ofVirtual().start(this::runRot13);
    Thread.ofVirtual().start(this::runConsoleOut);

    Thread.ofVirtual().start(
        () -> mediate("consoleIn.outbox", "rot13.inbox")
    );

    Thread.ofVirtual().start(
        () -> mediate("rot13.outbox", "consoleOut.inbox")
    );

    Thread.currentThread().join();
}