import java.util.Scanner;

public class Validation {

    /** Checks if a string can be converted into a double, and converts it.
    If the string can't be converted, it forces the user to enter something
    that can be converted, and then converts into into a double. */
    public double checkAndForceDouble (String stringToBeChecked, String messageToUser) {

        Scanner input = new Scanner(System.in);
        boolean isValid = false;
        double b = 0;

        try {
            b = Double.parseDouble(stringToBeChecked);
            isValid = true;
        } catch (Exception e) {}

        while (isValid == false) {
            System.out.print(messageToUser);
            stringToBeChecked = input.next();
            try {
                b = Double.parseDouble(stringToBeChecked);
                isValid = true;
            } catch(Exception e) {}
        }
        return b;
    }

    /** Checks if a string can be converted into a integer, and converts it.
    If the string can't be converted, it forces the user to enter something
    that can be converted, and then converts into into a integer. */
    public int checkAndForceInt (String stringToBeChecked, String messageToUser) {

        Scanner input = new Scanner(System.in);
        boolean isValid = false;
        int b = 0;

        try {
            b = Integer.parseInt(stringToBeChecked);
            isValid = true;
        } catch (Exception e) {}

        while (isValid == false) {
            System.out.print(messageToUser);
            stringToBeChecked = input.next();
            try {
                b = Integer.parseInt(stringToBeChecked);
                isValid = true;
            } catch(Exception e) {}
        }
        return b;
    }

    /** Checks if an integer is within the specified range. If it isn't, it will force the user
    to enter an integer which is within the range. */
    public int checkAndForceIntBounds (int numToBeChecked, int lowerBound, int upperBound, boolean
            inclusive, String errorMessage) {

        Scanner input = new Scanner(System.in);
        boolean outOfBounds = true;
        String tempNumHolder = "";

        if(inclusive == true) {
            if(numToBeChecked>=lowerBound && numToBeChecked<=upperBound) {
                outOfBounds = false;
            }

            while(outOfBounds==true) {
                System.out.print(errorMessage);
                tempNumHolder = input.next();
                numToBeChecked = checkAndForceInt(tempNumHolder, errorMessage);
                if(numToBeChecked>=lowerBound && numToBeChecked<=upperBound) {
                    outOfBounds = false;
                }
                                }
            }

        if(inclusive == false) {
            if(numToBeChecked>=lowerBound && numToBeChecked<upperBound) {
                outOfBounds = false;
            }

            while(outOfBounds==true) {
                System.out.println(errorMessage);
                tempNumHolder = input.next();
                numToBeChecked = checkAndForceInt(tempNumHolder, errorMessage);
                if(numToBeChecked>=lowerBound && numToBeChecked<upperBound) {
                    outOfBounds = false;
                }
                                }

            }
        return numToBeChecked;
        }

    /** Checks if a double is within the specified range. If it isn't, it will force the user
    to enter a double which is within the range. */
    public double checkAndForceDoubleBounds(double numToBeChecked, double lowerBound, double upperBound,
            boolean inclusive, String errorMessage) {
    Scanner input = new Scanner(System.in);
    boolean outOfBounds = true;
    String tempNumHolder = "";

    if(inclusive == true) {
        if(numToBeChecked>=lowerBound && numToBeChecked<=upperBound) {
            outOfBounds = false;
        }

        while(outOfBounds==true) {
            System.out.print(errorMessage);
            tempNumHolder = input.next();
            numToBeChecked = checkAndForceDouble(tempNumHolder, errorMessage);
            if(numToBeChecked>=lowerBound && numToBeChecked<=upperBound) {
                outOfBounds = false;
            }
                            }
        }

    if(inclusive == false) {
        if(numToBeChecked>=lowerBound && numToBeChecked<upperBound) {
            outOfBounds = false;
        }

        while(outOfBounds==true) {
            System.out.println(errorMessage);
            tempNumHolder = input.next();
            numToBeChecked = checkAndForceDouble(tempNumHolder, errorMessage);
            if(numToBeChecked>=lowerBound && numToBeChecked<upperBound) {
                outOfBounds = false;
            }
                            }

        }
    return numToBeChecked;
    }



    /** Inputs and validates an integer, with the option of checking if the integer is negative.
     * Also displays a message before inputting the data
     *
     *  inputMessage: message displayed before inputting the data
     *  dataWrongMessage: message displayed when user enters invalid data
     *  checkNegative: if true, forces the user to enter a positive number
     * */
    public int nextIntValidated(String inputMessage, String dataWrongMessage, boolean checkNegative) {

        Scanner input = new Scanner(System.in);
        int num = 0;
        String rawInput = "";

        System.out.print(inputMessage);
        rawInput = input.next();

        //run some checks on the input data
        num = checkAndForceInt(rawInput,dataWrongMessage);

        //force the user to enter a positive value if checkNegative is true
        if (checkNegative == true) {
            while(num<0) {
                System.out.println(dataWrongMessage);
                rawInput = input.next();
                num = checkAndForceInt(rawInput, dataWrongMessage);
            }
        }
        return num;
    }

    /** Inputs and validates a double, with the option of checking if the double is negative.
     * Also displays a message before inputting the data
     *
     *  inputMessage: message displayed before inputting the data
     *  dataWrongMessage: message displayed when user enters invalid data
     *  checkNegative: if true, forces the user to enter a positive number
     * */
    public double nextDoubleValidated(String inputMessage, String dataWrongMessage, boolean checkNegative) {

    Scanner input = new Scanner(System.in);
    double num = 0;
    String rawInput = "";

    System.out.print(inputMessage);
    rawInput = input.next();

    //ensure that a double can be retrieved
    num = checkAndForceDouble(rawInput,dataWrongMessage);

    //force the user to enter a positive value if checkNegative is true
    if (checkNegative == true) {
        while(num<0) {
            System.out.println(dataWrongMessage);
            rawInput = input.next();
            num = checkAndForceDouble(rawInput, dataWrongMessage);
        }
    }
    return num;
}
    }