import java.util.Scanner;

/**
 * This is the 2nd 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 BetterTaxHelper{
    private Scanner scan;

    /**
     * Creates a new tax helper
     */
    public BetterTaxHelper(){
        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?");

            // Under 65 years old
            if(isYes){
                isYes = getUserResponse("Is your gross income less than $8450?");

                // Less than income threshold
                if(isYes){
                    printDecision(false);
                }
                // More than income threshold
                else{
                    printDecision(true);
                }                   
            }

            // Over 65 years old
            else{
                isYes = getUserResponse("Is your gross income less than $9700?");

                // Less than income threshold
                if(isYes){
                    printDecision(false);
                }
                // More than income threshold
                else{
                    printDecision(true);
                }   
            }
        }

        // Married
        else{
            isYes = getUserResponse("Are you and your spouse both over 65?");

            // Over 65
            if(isYes){
                isYes = getUserResponse("Is your combined gross income less than $23,000?");

                // Less than income threshold
                if(isYes){
                    printDecision(false);
                }
                // More than income threshold
                else{
                    printDecision(true);
                }   

            }

            // At least one person is under 65
            else{
                isYes = getUserResponse("Are you and your spouse both under 65?");

                // Both under 65
                if(isYes){
                    isYes = getUserResponse("Is your combined gross income less than $20,600?");

                    // Less than income threshold
                    if(isYes){
                        printDecision(false);
                    }
                    // More than income threshold
                    else{
                        printDecision(true);
                    }    
                }

                // One person over 65 and one person under 65
                else{
                    isYes = getUserResponse("Is your combined gross income less than $21,800?");

                    // Less than income threshold
                    if(isYes){
                        printDecision(false);
                    }
                    // More than income threshold
                    else{
                        printDecision(true);
                    }   
                }
            }
        }
    }

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

    /**
     * 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");
        }
    }

}