/*
\\------------------------------------------//
//   CSCI 1100                               \\
\\  Primary Education Project               //
//  Part 2                                  \\
\\  Brennan Collier                               //
//------------------------------------------\\
*/

import java.util.Scanner;
import java.util.Random;

public class ArithmeticChallengeVersion2{
    public static void main(String[] args){

        Scanner keyboard = new Scanner(System.in);
        Random generator = new Random();

        //Variable Declaration
        int level = 0, i, count = 0, num1 = 0, num2 = 0, input, answer = 0;
        String name, challenge;

        //Introduction and Name Input
        System.out.println("HI - I am your friendly Math Tutor.");
        System.out.print("What is your name? ");
        name = keyboard.nextLine();

        //Challenge Select
        System.out.println("What challenge do you choose?");
        System.out.println("1 - Addition");
        System.out.println("2 - Subtraction");
        System.out.println("3 - Division");
        System.out.println("4 - Multiplication");
        challenge = keyboard.nextLine();

        //Level Select
        System.out.print("What level do you choose? Enter 1, 2 or 3: ");
        level = keyboard.nextInt();

        //Clarifying Statement
        System.out.println( );
        System.out.println("OK " + name + "!");
      System.out.print("Here are 10 " + challenge);
        System.out.println(" exercises for you at level " + level + ".");
        System.out.println("Good Luck! :D");
        System.out.println( );

        //Challenge Select
        if(challenge.equalsIgnoreCase("addition")||challenge.equals("+"))
            count = additionChallenge(level);
        else if(challenge.equalsIgnoreCase("subtraction")||challenge.equals("-"))
            count = subtractionChallenge(level);
        else if(challenge.equalsIgnoreCase("division")||challenge.equals("/"))
            count = divisionChallenge(level);
        else if(challenge.equalsIgnoreCase("multiplication")||challenge.equals("x"))
            count = multiplicationChallenge(level);
        else{
            System.out.println("ERROR - Invalid Input!");
            System.exit(0);
        }

        //Results
        System.out.println();
        System.out.println("You got " + count + " right out of 10");

        //Advisory Statement
        if(count >= 9 && level != 3)
            System.out.println("Select a higher level of difficulty next time.");
        else if(count == 9 && level == 3)
            System.out.println("Please try the test agian!");
        else if(count >= 6 && count <= 8)
            System.out.println("Please try the test again!");
        else if(count < 6 && level == 1)
            System.out.println("You should ask for Extra Help from your teacher!");
        else if(count < 6 && level != 1)
            System.out.println("Select a lower level of difficulty next time!");
        else if(level == 3 && count == 10){
            System.out.println("Excellent!");
            System.out.print("This program is not of any further use to you!");
        }
        //Closing Statement
        System.out.println(" Bye!");
    }

    //Addition Challenge
    public static int additionChallenge(int level){
        Scanner keyboard = new Scanner(System.in);
        Random generator = new Random();

        int i, count = 0, num1 = 0, num2 = 0, input, answer = 0;
        String name;

        for(i = 0; i < 10; i++){
        //Level 1
            if(level == 1){
            //Two random numbers generated num1 range[1,9] num2 range[1,9]  with answer less than 10
                num1 = generator.nextInt(9 -1 +1)+1;
                num2 = generator.nextInt(9 -1 +1)+1;
                answer = num1 + num2;
                //Restricts the answer to less than 10
                while(answer > 10){
                    num1 = generator.nextInt(9);
                    answer = num1 + num2;
                }
            }
        //Level 2
            if(level == 2){
            //Two random numbers generated num1 range[1,9] num2 range[1,9]
                num1 = generator.nextInt(9 -1 +1)+1;
                num2 = generator.nextInt(9 -1 +1)+1;
                answer = num1 + num2;
            }
        //Level 3
            if(level == 3){
            //Two random numbers generated num1 range[1,50] num2 range[1,50]
                num1 = generator.nextInt(50-1 +1)+1;
                num2 = generator.nextInt(50-1 +1)+1;
                answer = num1 + num2;
            }
            //User's Answer
            System.out.print(num1 + " + " + num2 + " = ");
            input = keyboard.nextInt();
            //Answer Checker
            if(input == answer){
                System.out.println("Correct!");
                count += 1;
            }
            else{
                System.out.print("Oops! ");
                System.out.println(num1 + " + " + num2 + " = " + answer);
            }
        }
        return count;
    }

    //Subtraction Challenge
    public static int subtractionChallenge(int level){
        Scanner keyboard = new Scanner(System.in);
        Random generator = new Random();

        int i, count = 0, num1 = 0, num2 = 0, input, answer = 0;
        String name;

        for(i = 0; i < 10; i++){
        //Level 1
            if(level == 1){
            //Two random numbers generated num1 range[1,9] num2 range[1,9]  with answer less than 10
                num1 = generator.nextInt(9 -1 +1)+1;
                num2 = generator.nextInt(9 -1 +1)+1;
                answer = num1 - num2;
                //Restricts the answer to less than 10 and greater than 0
                while(answer > 10 && answer < 0){
                    num1 = generator.nextInt(9);
                    answer = num1 - num2;
                }
            }
        //Level 2
            if(level == 2){
            //Two random numbers generated num1 range[1,50] num2 range[1,9]
                num1 = generator.nextInt(50 -1 +1)+1;
                num2 = generator.nextInt(9 -1 +1)+1;
                answer = num1 - num2;
                //Restricts answer to greater than 0
                while(answer <= 0){
                    num1 = generator.nextInt(9-1 +1)+1;
                    answer = num1 - num2;
                }
            }
        //Level 3
            if(level == 3){
            //Two random numbers generated num1 range[1,50] num2 range[1,100]
                num1 = generator.nextInt(50-1 +1)+1;
                num2 = generator.nextInt(100-1 +1)+1;
                answer = num1 - num2;
                //Restricts answer to greater than 0
                while(answer <= 0){
                    num1 = generator.nextInt(50-1 +1)+1;
                    answer = num1 - num2;
                }
            }

            //User's Answer
            System.out.print(num1 + " - " + num2 + " = ");
            input = keyboard.nextInt();

            //Answer Checker
            if(input == answer){
                System.out.println("Correct!");
                count += 1;
            }
            else{
                System.out.print("Oops! ");
                System.out.println(num1 + " - " + num2 + " = " + answer);
            }
        }
        return count;
    }

    //Division Challenge
    public static int divisionChallenge(int level){
        Scanner keyboard = new Scanner(System.in);
        Random generator = new Random();

        int i, count = 0;
        int num1 = 0, num2 = 0, input, answer = 0;
        String name;

        for(i = 0; i < 10; i++){
        //Level 1
            if(level == 1){
            //Two random numbers generated num1 range[1,20] num2 range[1,20]    with answer less than 10
                num1 = generator.nextInt(20 -1 +1)+1;
                num2 = generator.nextInt(20 -1 +1)+1;
                answer = num1 / num2;
                //Restricts the answer to less than 10
                while(num1%num2 != 0){
                    num1 = generator.nextInt(20);
                    answer = num1 / num2;
                }
            }
        //Level 2
            if(level == 2){
            //Two random numbers generated num1 range[1,50] num2 range[1,50]
                num1 = generator.nextInt(50 -1 +1)+1;
                num2 = generator.nextInt(50 -1 +1)+1;
                answer = num1 / num2;
                //Restricts the answer to whole intger numbers
                while(num1%num2 != 0){
                    num1 = generator.nextInt(50 -1 +1)+1;
                    answer = num1 / num2;
                }
            }
        // Level 3
            if(level == 3){
            //Two random numbers generated num1 range[1,100] num2 range[1,100]
                num1 = generator.nextInt(100-1 +1)+1;
                num2 = generator.nextInt(100-1 +1)+1;
                answer = num1 / num2;
                //Restricts the answer to whole intger numbers
                while(num1%num2 != 0){
                    num1 = generator.nextInt(100-1 +1)+1;
                    answer = num1 / num2;
                }
            }

            //User's Answer
            System.out.print(num1 + " ÷ " + num2 + " = ");
            input = keyboard.nextInt();

            //Answer Checker
            if(input == answer){
                System.out.println("Correct!");
                count += 1;
            }
            else{
                System.out.print("Oops! ");
                System.out.println(num1 + " ÷ " + num2 + " = " + answer);
            }
        }
        return count;
    }

    //Multiplication Challenge
    public static int multiplicationChallenge(int level){
        Scanner keyboard = new Scanner(System.in);
        Random generator = new Random();

        int i, count = 0;
        int num1 = 0, num2 = 0, input, answer = 0;
        String name;

        for(i = 0; i < 10; i++){
        //Level 1
            if(level == 1){
            //Two random numbers generated num1 range[1,9] num2 range[1,9]  with answer less than 10
                num1 = generator.nextInt(9 -1 +1)+1;
                num2 = generator.nextInt(9 -1 +1)+1;
                answer = num1 * num2;
                //Restricts the answer to less than 10
                while(answer > 10){
                    num1 = generator.nextInt(9);
                    answer = num1 * num2;
                }
            }
        //Level 2
            if(level == 2){
            //Two random numbers generated num1 range[1,9] num2 range[1,9]
                num1 = generator.nextInt(9 -1 +1)+1;
                num2 = generator.nextInt(9 -1 +1)+1;
                answer = num1 * num2;
            }
        // Level 3
            if(level == 3){
            //Two random numbers generated num1 range[1,50] num2 range[1,50]
                num1 = generator.nextInt(25-1 +1)+1;
                num2 = generator.nextInt(25-1 +1)+1;
                answer = num1 * num2;
            }

            //User's Answer
            System.out.print(num1 + " x " + num2 + " = ");
            input = keyboard.nextInt();

            //Answer Checker
            if(input == answer){
                System.out.println("Correct!");
                count += 1;
            }
            else{
                System.out.print("Oops! ");
                System.out.println(num1 + " x " + num2 + " = " + answer);
            }
        }
        return count;
    }

}