import java.util.*;

public class LibraryBooks2{



    public static void main(String[] args){

        System.out.println("This program calculates the profits and orders of books");
        System.out.println("Enter \"quit\" at any time to quit ");
        userInteraction();
        //math();
        //printInfo();



    }

    public static void userInteraction(){

        q1(); //new book
        q2(); //book id
        q3(); //book cost
        q4(); //# of copies
        q5(); //# of students in class
        q6(); //book required
        q7(); //book new to school



    }

    public static void q1(){  //new book
        Scanner scanner = new Scanner(System.in);
        String qNum = "q1";
        System.out.println("Do you want to add a book? ( y / n )");
        ynValidation(scanner.nextLine(),qNum);

    }

    public static void q2(){  //book id
        Scanner scanner = new Scanner(System.in);
        String qNum = "q2";
        System.out.println("What is the book ID? ( y / n )");
        String bookID=scanner.nextLine();
        System.out.println("You entered: " +bookID + "\nIs this correct? ( y / n )");
        ynValidation(scanner.nextLine(), qNum);
    }

    public static void q3(){   //book cost
        Scanner scanner = new Scanner(System.in);
        String qNum = "3";
        System.out.println("What is the cost of the book?");
        double validNum = numValidation(qNum);
        System.out.println("You entered: $" +validNum + ".  Is this correct? ( y / n )");
        ynValidation(scanner.nextLine(), qNum);


    }

    public static void q4(){  //# of copies in storage
        Scanner scanner = new Scanner(System.in);
        String qNum = "4";
        System.out.println("How many copies of this book are currently in storage?");
        double validNum = numValidation(qNum);
        int validInt = (int) validNum;
        System.out.println("Confirm there are "+validInt+" copies in storage? ( y / n )");
        ynValidation(scanner.nextLine(), qNum);

    }

    public static void q5(){  //# of students in class
        Scanner scanner = new Scanner(System.in);
        String qNum = "5";
        System.out.println("How many students are enroled in class?");
        double validNum = numValidation(qNum);
        int validInt = (int) validNum;
        System.out.println("Confirm there are "+validInt+" students in class? ( y / n )");
        ynValidation(scanner.nextLine(), qNum);

    }

    public static void q6(){  //book required?
        Scanner scanner = new Scanner(System.in);
        String qNum = "6";
        System.out.println("Is this book required for class? ( y / n )");
        //double validNum = numValidation(qNum);
        //int validInt = (int) validNum;
        //System.out.println("Confirm there are "+validInt+"copies in storage? ( y / n )");
        ynValidation(scanner.nextLine(), qNum);

    }

    public static void q7(){  //new book to school
        Scanner scanner = new Scanner(System.in);
        String qNum = "7";
        System.out.println("Is this book new to school? ( y / n )");
        //double validNum = numValidation(qNum);
        //int validInt = (int) validNum;
        //System.out.println("Confirm there are "+validInt+"copies in storage? ( y / n )");
        ynValidation(scanner.nextLine(), qNum);

    }


    public static double numValidation(String x){
        Scanner scanner = new Scanner(System.in);
        double y=0;
        if(x.equals("3")){
            try{
                y = scanner.nextDouble();
            }catch(InputMismatchException exception)
            {
                System.out.println("Invalid input, please input a number");
                q3();
            }
        }
        if(x.equals("4")){

            try{
                y = scanner.nextDouble();
            }catch(InputMismatchException exception)
            {
                System.out.println("Invalid input, please input a number");
                q4();
            }
            if(!(y % 1==0)){
                System.out.println("Invalid input, please input a WHOLE number");
                q4();
            }
        }
        if(x.equals("5")){

            try{
                y = scanner.nextDouble();
            }catch(InputMismatchException exception)
            {
                System.out.println("Invalid input, please input a number");
                q5();
            }
            if(!(y % 1==0)){
                System.out.println("Invalid input, please input a WHOLE number");
                q5();
            }
        }


        return y;

        //
        //        if(x <= 0){
        //            System.out.println("please enter a valid number");
        //        }
        //


    }



    public static String ynValidation(String x, String y){
        if(x.equals("quit")||x.equals("QUIT")){
            System.out.println("Program exiting...");
            System.exit(0);
        }
        if(x.equals("n")|| x.equals("N")){
            if(y.equals("q1")){
                q1();
            }
            if(y.equals("q2")){
                q2();
            }
            if(y.equals("q3")){
                q3();
            }
            //System.out.println("Program exiting...");
            //System.exit(0);
        }
        if(!(x.equals("y") || x.equals("Y"))){
            System.out.println("invalid choice -- please try again or enter \"quit\" to exit");
            if(y.equals("q1")){
                q1();
            }
            if(y.equals("q2")){
                q2();
            }
            if(y.equals("q3")){
                q3();
            }
            if(y.equals("q4")){
                q4();
            }
            if(y.equals("q5")){
                q5();
            }
            if(y.equals("q6")){
                q6();
            }
        }




        return null;





    }



}