using System;

public class Program

{

    public static void Main()

    {

        //Each year, IUK Corp.provide students loan for those in need. 

        //However, the maximum loan amount each student can get is different. 

        //In this assignment, your job is to create a console application that allows students to enter the following information:

        //household income, types of students (u= undergraduate, g = graduate), email, and birthday.

        //The program should show two results after a user enters all the input. 

        //All output should be formatted appropriately as currency

        //(Hint: ToString()).

        //================================================================================================================================

        //1. You must check that the household incomeentered by the user is aninteger.

        //If the user enters something other than anumber, your program should communicate that to the user.

        //If the user enters a numberthat is less than 0, the application should request the user to enter a non-negative number.

        //1)Consider using the function TryParse()to test whether the string entered by the user is a number.

        Console.WriteLine("Please enter your household income: ");

        string strIncome = Console.ReadLine( );

        int intIncome;

        if (int.TryParse(strIncome, out intIncome) && intIncome >= 0)

        {

​

        }

        else

        {

            Console.WriteLine("Please enter a valid number!");

            return;

        }

        //2. For student types, you should check whether users enter "U"or "G". 

        //If not, you should ask the users to reenter the corrected information. 

        //In addition, the program is case insensitive and white space insensitive, which means "U", "   U    ","u"are the same for the program.

        Console.WriteLine("Enter the letter u if you are an undergraduate student or the letter g if you are a graduate student.");

        string strType = Console.ReadLine( );

        if (strType == "u" || strType == "g")

        {

        }

        else

        {

        Console.WriteLine("Please enter either the letter u or the letter g.");

        return;

        }

        //3. Email should contain @.

        //If an email doesn’t contain @, the program should communicate that to the user

        Console.WriteLine("Please enter your email address.");

        string stremailaddress = Console.ReadLine( );

        int intStringSize = stremailaddress.Length;

        int intCondition = intStringSize - 1;

        int intAtSign = stremailaddress.IndexOf("@");

        if (intAtSign <= 0 || stremailaddress.EndsWith("@"))

        {

            Console.WriteLine("Please enter a valid email address!");

            return;

        }

        else

        {

            int intstartIndexU = 0;

            int intlengthU = (intAtSign);

            string strUsername = stremailaddress.Substring(intstartIndexU, intlengthU);

            int intstartIndexD = (intAtSign + 1);

            int intlengthD = (intStringSize - intstartIndexD);

            string strDomain = stremailaddress.Substring(intstartIndexD, intlengthD);

            Console.WriteLine("Username: "+ strUsername);

            Console.WriteLine("Domain: "+ strDomain);

        }

        //4. For the birthday, assume a user would only use the following format: “xx/xx/xxxx” (e.g., 09/04/1999).

        //(This means you do not have to validate birthdayformat.)

        Console.WriteLine("Please enter your birthday.");

        string strBirthday = Console.ReadLine( );

        //Rules to calculate loan:

        //1.For an undergraduate student, the default loan amount is $30,000.

        //However, if the household’s income is greater than 70,000, the loan amount is $20,000.

        //2.For a graduate student, the default loan amountis $50,000.

        //However, if the household’s income is greater than 90,000, the loan amount is $40,000.

        //(Hint: Use a Nested if to calculate the loan.)

        if (strType == "u")

        {

            if (intIncome > 70000)

            {

                Console.WriteLine("Loan amount: $20,000");

            }

            else if (intIncome <= 70000)

            {

                Console.WriteLine("Loan amount: $30,000");

            }

        }

        else if (strType == "g")

        {

            if (intIncome > 90000)

            {

                Console.WriteLine("Loan amount: $40,000");

            }

            else if (intIncome <= 90000)

            {

                Console.WriteLine("Loan amount: $50,000");

            }

        }

        //3.After you calculate the loan, you should further consider the following two casesto calculate the “extra loan amount.”

        //•IU studentsoIUK Corp. would like to provide an extra $3,000 loan amount for IU students.

        //oIf a student’s email domain equals "iu.edu", the student is anIU student.

        string[] strDate = strBirthday.Split('/');

        string strDay = strDate[0].ToString();

        string strMonth = strDate[1].ToString();

        string strYear = strDate[2].ToString();

        int intDay = Convert.ToInt32(strDay);

        int intMonth = Convert.ToInt32(strMonth);

        int intYear = Convert.ToInt32(strYear);

        int intBirthdayValue = intDay + intMonth + intYear;

        int intstartIndexD1 = (intAtSign + 1);

        int intlengthD1 = (intStringSize - intstartIndexD1);

        string strDomain1 = stremailaddress.Substring(intstartIndexD1, intlengthD1);

        if (intBirthdayValue % 4 == 0 && strDomain1 == "iu.edu")

        {

            Console.WriteLine("Extra Loan Amount: $5,000");

        }

        else if (intBirthdayValue % 4 == 0 && strDomain1 != "iu.edu")

        {

            Console.WriteLine("Extra Loan Amount: $2,000");

        }

        else if (strDomain1 == "iu.edu" && intBirthdayValue % 4 != 0);

        {

            Console.WriteLine("Extra Loan Amount: $3,000");

        }

        //•Lucky draw

        //oSumming up the value of an individual’s Day, Month, and Year of birthday. 

        //(e.g. 06/15/1999=> 6 + 15 + 1999= 2020)

        //oIf the value can be divisible by 4, the student gets an extra $2,000loan amount.

        //4)Use string functionssuch as Splits,Convert functionsand % (math operator)to complete the lucky draw.

        //4.Print out “Loan Amount” and “Extra Loan Amount”, separately.

        //2)Consider using ToString() to format your output.

    }

}