In some older homes that do not have a central heating and air conditioning system, smaller air conditioning units made to fit inside of a window and cool a single room are used as an alternative way to cool the home. Depending on the size of the room and the amount of shade that the room has, different sizes of air conditioning units must be used in order to be able to properly cool the room.  The unit of measure for the amount of cooling that an air conditioner unit can provide is the BTU (British Thermal Unit) per hour.  Code a program that will calculate the correct size of air conditioner for a specific room size using the instructions below. Step 1:

import java.util.Scanner;

/**
 * Class: AirConditioningCapacity
 * File: AirConditioningCapacity.java
 * Purpose: To calculate ac unit capacity based on user input
 */
public class AirConditioningCapacity {
    //constants for different ac capacity based on room areas
    private static final double CAPACITY_FOR_ROOM_UNDER_250 = 5500;
    private static final double CAPACITY_FOR_ROOM_250_TO_500 = 10000;
    private static final double CAPACITY_FOR_ROOM_OVER_500_UNDER_1000 = 17500;
    private static final double CAPACITY_FOR_ROOM_1000_OR_GREATER = 24000;
    
    //constants defined for increase or decrease in capacity based on room shade
    private static final double CAPACITY_INCREASE_FOR_LITTLE_SHADE = 0.15; //15%
    private static final double CAPACITY_DECREASE_FOR_ABUNDANT_SHADE = 0.10; //10%
    
    //all room shades are defined in array
    private static final String[] roomShades = {"Little Shade","Moderate Shade","Abundant Shade"};
    
    //main method starts
    public static void main(String[] args){
        //scanner instance created
        Scanner sc = new Scanner(System.in);
        
        int roomCounter = 0; //this will keep track of number of rooms
        
        //continue to take rooms as long as user wants
        do{
            roomCounter++; //keep track of number of rooms entered
            
            System.out.println("Please enter the name of the room: ");
            String roomName = sc.nextLine(); //read name of room
            
            System.out.println("Please enter the length of the room (in feet): ");
            double length = Double.parseDouble(sc.nextLine());//read length
            
            System.out.println("Please enter the width of the room (in feet): ");
            double width = Double.parseDouble(sc.nextLine());//read width
            
            System.out.println("What is the amount of shade that this room receives?");
            for(String shade: roomShades){//print different room shades
                System.out.println(shade);
            }
            
            System.out.println("Please select from the options above: ");
            int amountOfShade = Integer.parseInt(sc.nextLine());//take data for amount of shade
            //translate room shade into String info
            String roomShade = translateShadeChoiceToString(amountOfShade);
            double area = calculateArea(length, width);     //calculate area of the room    
            double acCapacity = calculateBTUsPerHour(area, amountOfShade);//calculate capacity
            displayTitle();//print title
            displayRoomInformation(roomName, area);//display room info
            //additionally prints room shade
            System.out.println("Room Shade: "+roomShade); 
            //finally prints capacity of the ac unit
            System.out.println("Capacity of the air conditioning unit "
                    + "(in BTU Per Hour): "+acCapacity);
            
            //checks if user wants to enter another room
            System.out.println("\nPress Y to enter another room or any other key to exit: ");
            String userChoice = sc.nextLine(); //read user's choice
            if(!userChoice.equalsIgnoreCase("Y")){ //if anything other than Y or y is entered
                break;//break out of the loop
            }
        }while(true);
        
        //print room counter
        System.out.println("Total number of rooms entered: "+ roomCounter);
    }
    
    /**
     * display title
     */
    public static void displayTitle(){
        System.out.println("Air Conditioning Window Unit Cooling Capacity");
    }
    
    /**
     * calculate area of the room
     * @param length
     * @param width
     * @return
     */
    public static double calculateArea(double length,double width){
        double area = 0;
        if(length > 0 && width > 0){
            area = length * width;
        }
        return area;
    }
    
    /**
     * convert amountOfShade to Stringequivlent
     * using roomShades array
     * @param amountOfShade
     * @return
     */
    public static String translateShadeChoiceToString(int amountOfShade){
        String shadeChoice = "Invalid Shade Choice";
        //if amount of shade is in range of number of shades
        if(amountOfShade >= 0 && amountOfShade <=roomShades.length){
            shadeChoice = roomShades[amountOfShade -1]; //take value from array
        }
        
        return shadeChoice;
    }
    
    /**
     * calculate capacity based on room area and amountOfShade
     * @param area
     * @param amountOfShade
     * @return
     */
    public static double calculateBTUsPerHour(double area,int amountOfShade){
        double capacityInBTUPerHour = 0;
        
        //check for different room sizes
        if(area < 250){
            capacityInBTUPerHour = CAPACITY_FOR_ROOM_UNDER_250;
        }else if(area >=250 && area <= 500){
            capacityInBTUPerHour = CAPACITY_FOR_ROOM_250_TO_500;
        }else if(area > 500 && area < 1000){
            capacityInBTUPerHour = CAPACITY_FOR_ROOM_OVER_500_UNDER_1000;
        }else if(area >= 1000){
            capacityInBTUPerHour = CAPACITY_FOR_ROOM_1000_OR_GREATER;
        }
        
        //check for different room shades
        if(amountOfShade ==1){ //for little shade increase by 15%
            capacityInBTUPerHour += capacityInBTUPerHour*CAPACITY_INCREASE_FOR_LITTLE_SHADE;
        }else if(amountOfShade ==2){ //for moderate shade no change
            //no change, keep it as it is
        }else if(amountOfShade == 3){//for abundant shade decrease by 10%
            capacityInBTUPerHour -= capacityInBTUPerHour*CAPACITY_DECREASE_FOR_ABUNDANT_SHADE;
        }
        
        return capacityInBTUPerHour;
    }
    
    /**
     * display room name and area
     * @param roomName
     * @param roomArea
     */
    public static void displayRoomInformation(String roomName,double roomArea){
        System.out.println("Room Name: "+roomName);
        System.out.println("Room Area (in square feet): "+roomArea);    
    }

}