/*
 * in this Java program, the user can calculate the area of a rectangle,
 *  and the volumes of a cube, cylinder, and sphere.
 * The user will be prompt to enter the length and width of a rectangle,
 * and then choose a shape to calculate the volume of (cube, cylinder, or sphere).
 */

import java.util.InputMismatchException;
import java.util.Scanner;

class Rectangle {
  public static double rectangleArea(double length, double width) {
    return length * width;
  }
}

class Cube {
  public static double cubeVolume(double side) {
    return Math.pow(side, 3);
  }
}

class Cylinder {
  public static double cylinderVolume(double radius, double height) {
    return Math.PI * Math.pow(radius, 2) * height;
  }
}

class Sphere {
  public static double sphereVolume(double radius) {
    return (4.0 / 3.0) * Math.PI * Math.pow(radius, 3);
  }
}
// Main Class

public class Main {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    try {
      // User prompt for the length and width
      System.out.println("Rectangle Area");
      System.out.print("Please enter length: ");
      double length = scanner.nextDouble();

      System.out.print("Please enter width: ");
      double width = scanner.nextDouble();

      // making sure that the user put positive numbers otherwise we throw a //warning

      if (length <= 0 || width <= 0) {
        System.out.println("WARNING! Length and width must be positive numbers.");
      } else {
        double area = Rectangle.rectangleArea(length, width);
        System.out.println("Rectangle Area: " + area);
      }

      // Choose shape for volume calculation

      System.out.println("");
      System.out.println("Volume Calculation");
      System.out.println("Choose a shape to calculate volume:");
      System.out.println("1. Cube");
      System.out.println("2. Cylinder ");
      System.out.println("3. Sphere ");
      System.out.print("Enter your choice (1-3): ");
      int userChoice = scanner.nextInt();
      // Let's give the User the choice of which volume shape they want to calculate.
      switch (userChoice) {
        case 1: // Cube
          System.out.print("Enter side length of cube: ");
          double side = scanner.nextDouble();
          if (side <= 0) {
            System.out.println("WARNING! Side must be a positive number.");
          } else {
            double cubeVolume = Cube.cubeVolume(side);
            System.out.println("Cube Volume: " + cubeVolume);
          }
          break;
        case 2: // Cylinder
          System.out.print("Enter radius of cylinder: ");
          double cylinderRadius = scanner.nextDouble();
          System.out.print("Enter height of cylinder: ");
          double cylinderHeight = scanner.nextDouble();
          if (cylinderRadius <= 0 || cylinderHeight <= 0) {
            System.out.println("WARNING! Radius and height must be positive numbers.");
          } else {
            double cylinderVolume = Cylinder.cylinderVolume(cylinderRadius, cylinderHeight);
            System.out.println("Cylinder Volume: " + cylinderVolume);
          }
          break;
        case 3: // Sphere
          System.out.print("Enter radius of sphere: ");
          double sphereRadius = scanner.nextDouble();
          if (sphereRadius <= 0) {
            System.out.println("WARNING! Radius must be a positive number.");
          } else {
            double sphereVolume = Sphere.sphereVolume(sphereRadius);
            System.out.println("Sphere Volume: " + sphereVolume);
          }
          break;
        default:
          System.out.println("Invalid choice.");
      }

    } catch (InputMismatchException e) {
      System.out.println("WARNING! Please enter valid numeric values.");
    } finally {
      scanner.close();
    }
  }
}