import java.util.ArrayList;
import java.util.Random;

/**
 * This class stores a list of books
 * @author cs161
 * @version spring2019
 */
public class BookCase{
    // Instance variables
    private ArrayList<Book> books;
    private Random rng;
    
    /**
     * Creates a new empty bookcase
     */
    public BookCase(){
        this.books = new ArrayList<Book>();
        this.rng = new Random();
    }

    /**
     * Adds a book to the book case
     * @param title The title of the book
     * @param author The author of the book
     */
    public void addBook(String title, String author){
        // Create a book using this information
        Book addition = new Book(title, author);

        // Add the book to the list
        this.books.add(addition);

    }

    /**
     * Checks if a book is contained in the book case
     * @param findBook The title of the book
     * @return True if the book occurs in the book case, false otherwise
     */    
    public boolean containsBook(String findBook){
        int current = 0;
        while(current < books.size()){
            Book b = books.get(current);
            String t = b.getTitle();
            if(t.equals(findBook)){
                return true;   
            }
            current++;
        }
        return false;
    }

    /**
     * Removes a book from the list
     * @param currPosition The index of the book to be moved
     */
    public void removeBook(int currPosition){
        if(currPosition >= 0 && currPosition < books.size()){
            books.remove(currPosition);
        }
    }

    /**
     * Returns the title of a random book in the book case
     * @return The title of a randomly chosen book
     */
    public String getRandomBook(){
        // Get a random position in the list
        int pickBook = rng.nextInt(books.size());
        
        // Get the book at that position
        Book rb = books.get(pickBook);
        
        // Return the title of that book
        return rb.getTitle();
    }

    /**
     * Returns a string representation of the state of the bookcase
     * @return A string representing the bookcase
     */
    public String toString(){
        int counter = 0;
        String result = "";
        while(counter < books.size()){
            Book b = books.get(counter);
            result = result + b.toString() + "\n";            
            counter++;
        }

        return result;
    }
}