package exercises.ex_n_bis;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

public class LibraryCatalog {
    private final Map<String, String> catalog = new HashMap<>();
    private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
    private final Lock readLock = lock.readLock();
    private final Lock writeLock = lock.writeLock();

    public LibraryCatalog() {

    }

    public ArrayList<Book> getBooks() {
        ArrayList<Book> books = new ArrayList<>();
        try {
            readLock.lock();
            catalog.forEach((title, author) -> {
                books.add(new Book(title, author));
            });
        } finally {
            readLock.unlock();
        }
        return books;
    }

    public String findBook(String title) {
        String author;
        try {
            readLock.lock();
            author = catalog.get(title);
        } finally {
            readLock.unlock();
        }
        if (author == null) {
            System.out.println("The book '" + title + "' is not in the catalog");
            return null;
        }
        return author;
    }

    public void addBook(String title, String author) {
        try {
            writeLock.lock();
            catalog.put(title, author);
        } finally {
            writeLock.unlock();
        }
    }

    public void removeBook(String title) {
        try {
            writeLock.lock();
            catalog.remove(title);
        } finally {
            writeLock.unlock();
        }
    }

    public void updateBook(String title, String newAuthor) {
        try {
            writeLock.lock();
            catalog.replace(title, newAuthor);
        } finally {
            writeLock.unlock();
        }
    }

    public record Book(String title, String author) {}
}