//Jim Stroud
//CS 201
//Section 6
//Extra Credit:  Problem 3, page 383
//____________________________________________________________
//Program calendar.cpp prints a calendar for one year, given
//the year and the day of the week that January 1 falls on.

#include <iostream.h>
#include <iomanip.h>

//Prints the calendar for a month.
void PrintMonthlyCalendar( int, int& );

//Gets the days in the month and prints the months name.
void GetMonthData( int, int, int& );

int main()
{
	int year;        //the year for the calendar
	int firstDay;    //first day of the year and each month
	int monthCount;  //counts the months of the year
	int daysInMonth; //the number of days in a given month

	//Prompt for input
   cout << endl << endl << endl << endl << endl;
	cout << "This program prints a calendar for one year, " << endl
		  << "given the year and the day of the week that "  << endl
		  << "January 1 falls on. " << endl << endl;

	cout << "Enter year( a four digit number): ";
	cin  >> year;

	cout << "Enter day( a digit, 0-6, for Sunday thru Saturday): ";
	cin  >> firstDay;

	//Print year heading
	cout << endl << endl << endl << endl << setw( 12 ) << year;

	//Print monthly calendar
	for( monthCount = 1; monthCount <= 12; monthCount++ )
	{
		GetMonthData( year, monthCount, daysInMonth );
		PrintMonthlyCalendar( daysInMonth, firstDay );
	}

}//end main().

//***********************************************************
//Gets the days in the month and prints the months name.
//
void GetMonthData( /*IN*/  int year,     //the calendar year
						 /*IN*/  int month,    //the calendar month
						 /*OUT*/ int& numDays )//# days in month
//
//Pre:  year, month have been assigned
//Post: year == year@entry
//	     month == month@entry
//		  numDays == the number of days in the month@entry
{
	cout << endl << endl << endl;

	switch( month )
	{
		case 1:
					numDays = 31;
					cout << setw ( 14 ) << "January";
					break;
		case 2:
					if( year % 4 )
						numDays = 28;
					else
						numDays = 29;  //leap year

					cout << setw ( 14 ) << "February";
					break;

		case 3:
					numDays = 31;
					cout << setw ( 13 ) << "March";
					break;
		case 4:
					numDays = 30;
					cout << setw ( 13 ) << "April";
					break;
		case 5:
					numDays = 31;
					cout << setw ( 12 ) << "May";
					break;
		case 6:
					numDays = 30;
					cout << setw ( 12 ) << "June";
					break;
		case 7:
					numDays = 31;
					cout << setw ( 12 ) << "July";
					break;
		case 8:
					numDays = 31;
					cout << setw ( 13 ) << "August";
					break;
		case 9:
					numDays = 30;
					cout << setw ( 15 ) << "September";
					break;
		case 10:
					numDays = 31;
					cout << setw ( 14 ) << "October";
					break;
		case 11:
					numDays = 30;
					cout << setw ( 14 ) << "November";
					break;
		case 12:
					numDays = 31;
					cout << setw ( 14 ) << "December";
					break;
	}//endswitch.

   cout << endl << endl;

}//end GetMonthData().

//***********************************************************
//Prints the calendar for a month
//
void PrintMonthlyCalendar( /*IN*/ int numDays,    //# days in month
									/*IN/OUT*/int& dayOne )//day of the week
																  //for 1st day
																  //of the month
//
//Pre:  numDays has been assigned the number of days in the month
//	  && dayOne has been assigned the number for the day of the
//			   week for the first day in the month
//Post: numDays == numDays@entry
//   && dayOne  == the number for the day of the week for the
//							   first day of the next month
{
	int dayCount;   //Counts the num days printed
	int widthParam; //Parameter to the setw() function

	//Heading for days of the week
	cout << setw( 3 ) << 'S'
		  << setw( 3 ) << 'M'
		  << setw( 3 ) << 'T'
		  << setw( 3 ) << 'W'
		  << setw( 3 ) << 'T'
		  << setw( 3 ) << 'F'
		  << setw( 3 ) << 'S' << endl
		  << " ____________________" << endl;

	for( dayCount = 1; dayCount <= numDays; dayCount++ )
	{
		//The first day of the month must go under proper heading.
		if( dayCount == 1 )
			widthParam = 3 * dayOne + 3;
		else
			widthParam = 3;

		cout << setw( widthParam ) << dayCount;

		//If the last day of the week has been reached...
		if( dayOne == 6 )
		{
			dayOne = 0;              //..reset as first weekday..
			if( dayCount < numDays ) //...go to a newline for a
				cout << endl;         //new week
		}
		else
			dayOne++;


	}

}//end printMonthlyCalendar().