import java.util.Scanner;
class Book{
	Scanner s = new Scanner(System.in);
	//Nested class for each entry
	class Entry{
		private String first;
		private String last;
		private String address;
		private String email;
		Entry(String first, String last, String address, String email){
			this.first = first;
			this.last = last;
			this.address = address;
			this.email = email;
		}
		Entry(){
			first = "";
			last = "";
			address = "";
			email = "";
		}
		public void readEntry(){
			System.out.println("First Name:"+first );
			System.out.println("Last Name:"+last );
			System.out.println("Address:"+address );
			System.out.println("Email:"+email );
		}
	}


	//Keeps track of how many entries are in the book
	private int entries = 0;
	Entry[] contents;
	public void initEntries(int e){
		contents = new Entry[e];
		for (int i = 0;i<contents.length;i++){		//Initializes an array of entries, then loops through to initialize each individual entry
			contents[i] = new Entry();
		}
	}
	public int getEntries(){
		return contents.length;
	}
	//Adds an entry to the book
	public void add(String first, String last, String address, String email){
		if (entries<contents.length){
		contents[entries] = new Entry(first, last, address, email);
		entries++;
		}
		else System.out.println("Error: book is full");
	}

	//Removes an entry from the book
	public void remove(int entry){
		if (entries>0){
			contents[entry] = new Entry();
			for (int i = 0;i<entries-entry;i++){
				if (entry+1==entries) contents[entry] = new Entry();
				else{
					Entry temp = contents[entry+i];
					contents[entry+i] = contents[entry+i+1]; //Removes an entry end moves each entry after it one backwards.
					contents[entry+i+1] = temp;
				}
			}
			entries--;
			}
			else System.out.println("Error: book is empty.");
	}

	//Changes the values of an entry
	public void edit(String first, String last, String address, String email, int selection){
		contents[selection].first = first;
		contents[selection].last = last;
		contents[selection].address = address;
		contents[selection].email = email;
	}

	//Sorts the book based on a part of the entry
	//int n is used to tell which part of the entries to base the sort on
	public void sort(int n){
		for(int i = 0;i<contents.length;i++){
			for (int j = 0;j<contents.length;j++){
				switch(n){
					case 1:
						if (contents[i].first.compareTo(contents[j].first)<0){
							Entry temp = contents[i];
							contents[i] = contents[j];
							contents[j] = temp;
						}
						break;
					case 2:
						if (contents[i].last.compareTo(contents[j].last)<0){
							Entry temp = contents[i];
							contents[i] = contents[j];
							contents[j] = temp;
						}
						break;
					case 3:
						if (contents[i].address.compareTo(contents[j].address)<0){
							Entry temp = contents[i];
							contents[i] = contents[j];
							contents[j] = temp;
						}
						break;
					case 4:
						if (contents[i].email.compareTo(contents[j].email)<0){
							Entry temp = contents[i];
							contents[i] = contents[j];
							contents[j] = temp;
						}
						break;
					default:
						System.out.println("Error: invalid field");
						break;
				}
			}
		}
	}
	public void addFromCopy(Entry e){
		if (entries<contents.length){
			contents[entries] = e;
			entries++;
			}
			else System.out.println("Error: book is full");
	}

}
public class AddressBook2 {
	public static void main(String[] args){
		Scanner s = new Scanner(System.in);
		System.out.print("How many books do you want to create? ");
		int howManyBooks;
		int howManyEntries;

		Book[] library = new Book[0];


		while(true){
			howManyBooks = s.nextInt();
			if (howManyBooks>0){
				library = new Book[howManyBooks];					//This code decides how many books are in the array of books/the library
				break;
			}
			else System.out.print("You must create at least 1 book.");
			}



		for (int i=0;i<library.length;i++){


			library[i] = new Book(); //Fixed reference to null because each book in the library had not been initialized yet.

			while(true){
				System.out.print("How many entries in book "+i+"? ");
				howManyEntries = s.nextInt();
				if (howManyEntries>0) {
					library[i].initEntries(howManyEntries);					//This code decides how many entries are in each book in the library
					break;
				}
				else System.out.println("You must create at least 1 Entry.");
				}


		}
		boolean done = false;
		int selectedBook = 0;
		int selection;
		while (done==false){
			System.out.println("Book "+selectedBook+" is currently selected.");

			for (int i = 0;i<library[selectedBook].getEntries();i++){
				System.out.println("===========Entry "+i+" ===========");
				library[selectedBook].contents[i].readEntry(); //Accessing the array of entries INSIDE the array of books/the library
				System.out.println("================================");
			}


			System.out.println("Select an option!");
			System.out.println("1. Add an entry");
			System.out.println("2. Remove an entry");
			System.out.println("3. Edit an entry");
			System.out.println("4. Sort all entries in this book");
			System.out.println("5. Select another book");
			System.out.println("6. Move entry across books");
			System.out.println("7. Exit the menu");
			System.out.print("> ");
			selection = s.nextInt();
			String first, last, address, email;
			switch(selection){
			case 1:
				System.out.print("First name? ");
				first = s.next();
				System.out.print("Last name? ");
				last = s.next();
				System.out.print("Address? ");
				address = s.next();
				System.out.print("Email? ");
				email = s.next();
				library[selectedBook].add(first, last, address, email);
				break;
			case 2:
				System.out.print("Remove which entry? ");
				int entry = s.nextInt();
				library[selectedBook].remove(entry);
				break;
			case 3:
				System.out.print("Edit which entry?");
				int whichEntry = s.nextInt();
				System.out.print("First name? ");
				first = s.next();
				System.out.print("Last name? ");
				last = s.next();
				System.out.print("Address? ");
				address = s.next();
				System.out.print("Email? ");
				email = s.next();
				library[selectedBook].edit(first, last, address, email, whichEntry);
				break;
			case 4:
				System.out.println("Sort alphabetically by which field?");
				System.out.println("1. Sort by first name");
				System.out.println("2. Sort by last name");
				System.out.println("3. Sort by address");
				System.out.println("4. Sort by email");
				library[selectedBook].sort(s.nextInt());
				break;
			case 5:
				System.out.print("Select which book?");
				selectedBook = s.nextInt();
				break;
			case 6:
				System.out.print("Move which entry? ");
				int entryNo = s.nextInt();
				Book.Entry entryToMove = library[selectedBook].contents[entryNo];
				library[selectedBook].remove(entryNo);
				System.out.print("To which book? ");
				int whichBook = s.nextInt();
				library[whichBook].addFromCopy(entryToMove);
				break;
			case 7:
				done = true;
				break;
			default:
				System.out.print("Please choose a valid menu number");


			}

		}
	}
}