/* Title: Gregorian Calendar
 * Authour: Robert B.
 * Assignemnt: Final ISU (Culnamating)
 * Date: June 18 2012
 */

public class finalISU
{
    public static void main (String[] args)
    {

        //variable declarations
        int mon = 1, date = 1900, y = 1900, y2 = 0, mon2 = 0, date2 = 0, n, i = 0, q = 0;
        int fday, start = 1900, dtotal = 0, dnum = 365, after;
        char option, loop1 = '$', loop2 = '$';
        boolean isleap, check = true;

        isleap = leapyear (y);

        while (loop1 == '$')
        {
            //prompts user for options
            System.out.println ("Please choose one of the following options: ");
            System.out.println ("(A) full calender/ (B) month / (C) day from date / (D) date from days / (E) Book Appointment");
            System.out.print ("Option: ");
            option = In.getChar ();

            //space
            System.out.println ();
            System.out.println ();
            System.out.println ();


            switch (option)
            {
                case 'A':

                    System.out.print ("Enter Year: ");
                    y = In.getInt ();
                    while (y < 1900)
                    {
                        System.out.println ("Error: must be a year after 1900");
                        System.out.print ("Enter Year: ");
                        y = In.getInt ();
                    }
                    //go to completecal method for info
                    completecal (y);
                    break;

                case 'B':

                    System.out.print ("Enter Year: ");
                    y = In.getInt ();


                    while (y < 1900)
                    {
                        System.out.println ("Error: must be a year after 1900");
                        System.out.print ("Enter Year: ");
                        y = In.getInt ();
                    }

                    System.out.print ("Enter Month (1-12): ");
                    mon = In.getInt ();


                    while (mon < 1 || mon > 12)
                    {
                        System.out.println ("Error: Invalid month");
                        System.out.println ("Enter Month (1-12): ");
                        mon = In.getInt ();
                    }

                    //
                    monthcal (y, mon);
                    break;

                case 'C':

                    System.out.print ("Enter Year: ");
                    y = In.getInt ();

                    while (y < 1900)
                    {
                        System.out.println ("Error: must be a year after 1900");
                        System.out.print ("Enter Year: ");
                        y = In.getInt ();
                    }

                    //


                    //
                    System.out.print ("Enter Month (1-12): ");
                    mon = In.getInt ();

                    while (mon < 1 || mon > 12)
                    {
                        System.out.println ("Error: Invalid month");
                        System.out.print ("Enter Month (1-12): ");
                        mon = In.getInt ();
                    }

                    //
                    System.out.print ("Enter Date (1-31): ");
                    date = In.getInt ();

                    //
                    while ((date < 1 || date > 31) || ((mon == 1 || mon == 3 || mon == 5 || mon == 7 || mon == 8 || mon == 10 || mon == 12) && date > 31))
                    {
                        System.out.println ("Error: Date must correspond to month");
                        System.out.print ("Enter Date (1-31): ");
                        date = In.getInt ();
                    }

                    while ((mon == 4 || mon == 6 || mon == 9 || mon == 11) && date > 30)
                    {
                        System.out.println ("Error: Date must correspond to month");
                        System.out.print ("Enter Date (1-31): ");
                        date = In.getInt ();
                    }

                    while ((mon == 2 && isleap == true) && date > 29)
                    {
                        System.out.println ("Error: Date must correspond to month");
                        System.out.print ("Enter Date (1-31): ");
                        date = In.getInt ();
                    }

                    //
                    WeekDay (y, mon, date);
                    break;

                case 'D':

                    //
                    System.out.print ("Enter Today's Year: ");
                    y = In.getInt ();

                    //
                    while (y < 1900)
                    {
                        System.out.println ("Error: Must be a year after 1900");
                        System.out.print ("Enter Today's Year: ");
                        y = In.getInt ();
                    }

                    System.out.print ("Enter Month (1-12): ");
                    mon = In.getInt ();

                    while (mon < 1 || mon > 12)
                    {
                        System.out.println ("Error: Invalid Month");
                        System.out.print ("Enter Month (1-12): ");
                        mon = In.getInt ();
                    }

                    System.out.print ("Enter Date (1-31): ");
                    date = In.getInt ();

                    //
                    while ((date < 1 || date > 31) || ((mon == 1 || mon == 3 || mon == 5 || mon == 7 || mon == 8 || mon == 10 || mon == 12) && date > 31))
                    {
                        System.out.println ("Error: Date must correspond to month");
                        System.out.print ("Enter Date (1-31): ");
                        date = In.getInt ();
                    }

                    while ((mon == 4 || mon == 6 || mon == 9 || mon == 11) && date > 30)
                    {
                        System.out.println ("Error: Date must correspond to month");
                        System.out.print ("Enter Date (1-31): ");
                        date = In.getInt ();
                    }

                    while ((mon == 2 && isleap == true) && date > 29)
                    {
                        System.out.println ("Error: Date must correspond to month");
                        System.out.print ("Enter Date (1-31): ");
                        date = In.getInt ();
                    }

                    System.out.println ("Enter number of days after today: ");
                    after = In.getInt ();

                    addDay (year, month, date, after);

                    System.out.println ();

                case 'E':

                    System.out.print ("Enter number of timeslots: ");
                    n = In.getInt ();
                    int[] slots = new int [n];
                    int[] slote = new int [n];
                    int holds = 0, holde = 0;


                    while (0 < n)
                    {

                        while (loop2 == '$')
                        {
                            System.out.print ("Enter Year of reservation: ");
                            y = In.getInt ();

                            while (y < 1900)
                            {
                                System.out.println ("Error: Must be a year after 1900");
                                System.out.print ("Enter Year of reservations: ");
                                y = In.getInt ();
                            }

                            System.out.print ("Enter Month of reservation (1-12): ");
                            mon = In.getInt ();

                            while (mon < 1 || mon > 12)
                            {
                                System.out.println ("Error: Invalid Month");
                                System.out.print ("Enter Month of reservation (1-12): ");
                            }

                            System.out.print ("Enter date of reservation (1-31): ");
                            date = In.getInt ();

                            while ((date < 1 || date > 31) || ((mon == 1 || mon == 3 || mon == 5 || mon == 7 || mon == 8 || mon == 10 || mon == 12) && date > 31))
                            {
                                System.out.println ("Error: Date must correspond to month");
                                System.out.print ("Enter Date of reservation (1-31): ");
                                date = In.getInt ();
                            }

                            while ((mon == 4 || mon == 6 || mon == 9 || mon == 11) && date > 30)
                            {
                                System.out.println ("Error: Date must correspond to month");
                                System.out.print ("Enter Date of reservation (1-31): ");
                                date = In.getInt ();
                            }

                            while ((mon == 2 && isleap == true) && date > 29)
                            {
                                System.out.println ("Error: Date must correspond to month");
                                System.out.print ("Enter Date of reservation (1-31): ");
                                date = In.getInt ();
                            }

                            if (mon < 3)
                            {
                                mon = mon + 12;
                                y = y - 1;
                            }
                            fday = ((date + (2 * mon) + (6 * mon + 1) / 10) + y + (y / 4) - (y / 100) = (y / 400) + 1) % 7);

                            if (mon > 12)
                            {
                                mon = mon - 12;
                                y = y + 1;
                            }
                            while (fday == 1 || fday == 2 || fday = 3 || fday = 4 || fday == 5)
                            {
                                System.out.println ("Error: The date is not a Saturday or Sunday. Try again.");
                                System.out.print ("Enter Date of reservation (1-31): ");
                                date = In.getInt ();
                            }

                            if (mon < 3)
                            {
                                mon = mon + 12;
                                y = y - 1;
                            }

                            fday = ((date + (2 ^ mon) + 6 * (mon + 1) / 10) + y + (y / 4) - (y / 100) + y / 400) + 1) % 7;

                            if (month > 12)
                            {
                                month = month - 12;
                                year = year + 1;
                            }
                        }







                    }
            }
        }


        public static boolean leapyear (int y)
        {
            if ((y % 4 == 0) && (y % 100 != 0 || y % 400 == 0))
                return true;
            else
                return false;
        }
    }