function generateRandomDate() {
    const year = Math.floor(Math.random() * (2024 - 1900)) + 1900;
    const month = Math.floor(Math.random() * 12) + 1;
    const day = Math.floor(Math.random() * 28) + 1;
    return new Date(year, month - 1, day);
}

function generateRandomAuthor() {
    const names = [
        'Александр',
        'Екатерина',
        'Дмитрий',
        'Анна',
        'Иван',
        'Мария',
        'Сергей',
        'Ольга',
        'Павел',
        'Наталья',
    ];
    const surnames = [
        'Иванов',
        'Петров',
        'Смирнов',
        'Кузнецов',
        'Васильев',
        'Соколов',
        'Михайлов',
        'Новиков',
        'Федоров',
        'Морозов',
    ];
    const randomName = names[Math.floor(Math.random() * names.length)];
    const randomSurname = surnames[Math.floor(Math.random() * surnames.length)];
    return {
        name: randomName,
        surname: randomSurname,
    };
}

function generateRandomBook() {
    return {
        title: 'Книга ' + Math.floor(Math.random() * 1000),
        genre: [
            'Фантастика',
            'Роман',
            'Детектив',
            'Фэнтези',
            'Приключения',
            'Исторический роман',
            'Триллер',
            'Поэзия',
            'Научно-популярная литература',
            'Юмористическая проза',
        ][Math.floor(Math.random() * 6)],
        publishDate: generateRandomDate(),
        author: generateRandomAuthor(),
        pageCount: Math.floor(Math.random() * 500) + 100,
    };
}

function createBooksArray(N) {
    const books = [];
    for (let i = 0; i < N; i++) {
        books.push(generateRandomBook());
    }
    return books;
}

function findBooksByAuthor(books, authorLastName) {
    const filteredBooks = books.filter((book) => {
        return book.author.surname === authorLastName;
    });

    return filteredBooks;
}

function findBooksByGenre(books, genre) {
    const filteredBooks = books.filter((book) => book.genre === genre);

    return filteredBooks;
}

function findBooksByPublishYearRange(books, startYear, endYear) {
    const filteredBooks = books.filter((book) => {
        const publishYear = book.publishDate.getFullYear();
        return publishYear >= startYear && publishYear <= endYear;
    });

    return filteredBooks;
}

function removeBooksPageCount(books, minPageCount) {
    for (let i = 0; i < books.length; i++) {
        if (books[i].pageCount < minPageCount) {
            delete books[i].pageCount;
        }
    }

    return books;
}

function addAgeInfoToBooks(books) {
    const currentDate = new Date();
    books.forEach((book) => {
        const yearsSincePublication =
            currentDate.getFullYear() - book.publishDate.getFullYear();
        book.age = yearsSincePublication;
    });

    return books;
}

// const booksArray = createBooksArray(10);
// console.log('Initial array of books:');
// displayBooks(booksArray);

// findBooksByAuthor(booksArray, 'Smith');
// findBooksByGenre(booksArray, 'Fantasy');
// findBooksByPublishYearRange(booksArray, 2000, 2010);

// booksArray = removeBooksByPageCount(booksArray, 200);
// console.log('Array after removing books by page count:');
// displayBooks(booksArray);

// booksArray = addAgeInfoToBooks(booksArray);
// console.log('Array after adding age info:');
// displayBooks(booksArray);