import java.util.Scanner;

/**
 * This is the final version of TaxHelper. This class illustrates how 
 * private methods can be used to
 * 
 * (1) Keep your methods short and concise
 * (2) Keep your code organized
 * (3) Reduce repeated code. Repeated code tempts us to copy-and-paste
 * which is one of the easiest ways to propagate errors.
 */
public class BestTaxHelper{
    private Scanner scan;

    /**
     * Creates a new tax helper
     */
    public BestTaxHelper(){
        scan = new Scanner(System.in);
        printWelcomeMessage();   
    }

    /**
     * Helps the user determine whether or not they need to file taxes
     */
    public void determineFilingStatus(){
        boolean isYes = getUserResponse("Are you single? (y/n)");

        // Single
        if(isYes){
            isYes = getUserResponse("Are you under 65 years of age?");
            if(isYes){
                askIncomeStatus(8450.0);                
            }
            else{
                askIncomeStatus(9700.0);
            }
        }

        // Married
        else{
            isYes = getUserResponse("Are you and your spouse both over 65?");
            if(isYes){
                askIncomeStatus(23000);
            }
            else{
                isYes = getUserResponse("Are you and your spouse both under 65?");
                if(isYes){
                    askIncomeStatus(20600);               
                }
                else{
                   askIncomeStatus(21800);
                }
            }
        }
    }

    /*================================================================
     *              Below are the private helper methods
     *================================================================*/

    /**
     * Prints a welcome message to the user
     */
    private void printWelcomeMessage(){
        System.out.println("=======================================");
        System.out.println("Welcome to the Tax Center!");
        System.out.println("We offer non-professional tax help.");
        System.out.println("Use at your own risk!");
        System.out.println();
    }

    /**
     * This method prints a yes-no question to the screen and then gets
     * the user's response
     * @param question a yes-no question
     * @return true if the answer to the question is yes and false otherwise
     */
    private boolean getUserResponse(String question){
        System.out.println(question);
        String input  = scan.nextLine();
        return input.equals("y");
    }

    /**
     * Prints the final decision
     * @param mustFile true if the user must file and false otherwise
     */
    private void printDecision(boolean mustFile){
        if(mustFile){
            System.out.println("Yes, you must file taxes.");
        }
        else{
            System.out.println("No, you do not need to file taxes");
        }
    }

    /**
     * Asks the user about their gross income. Based on the response, 
     * a final decision is made.
     * @param incomeAmount the gross income
     */
    private void askIncomeStatus(double incomeAmount){
        boolean isYes = getUserResponse("Is your gross income less than " + incomeAmount);
        if(isYes){
            printDecision(false);
        }
        else{
            printDecision(true);
        }    
    }

}