#!perl
#
#  Copyright 2000 Philip Yuson
#  http://www.conceptsolutionsbc.com
#  Distributed as per the Perl copyright agreement.
#
# This script was written to illustrate Perl/Tk statements.
# it was written with Windows in mind as if this were written for
# Linux or Unix, I would have used the 'cal' command and the routines
# would be a lot simpler.
#
# How it works:
#
# perl calendar.pl [year] [month]
#                   year and month should be numeric.
#
# Revision Log:
# Key: R01-001
# Date: 5 January 2001
# Inspired by Eric Rosenfield
# Program gets the current date if no parameter passed to it.
#
# Key: R01-002
# Date: 13 January 2001
# Reported by: Rudi Farkas
# Rows for calendar increased to 8 instead of 7.
#
# Key: R01-003
# Date: 13 February 2001
# Reported by: William Curtis
# Error when displaying days in February.
#
# Name: Calendar Program in Perl/Tk

use strict;
use Tk;             # of course you need this
use Date::Calc;     # you need this to calculate your date


# Parms entered are year and month
my ($year, $month) = @ARGV;

# set the maximum number of days for each month
my @maxdays = (0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);

# R01-001 Begin
($year, $month) = (Date::Calc::Today())[0, 1] unless ("$year$month");
# R01-001 End
# Set $a to get the day of the week
my $a = Date::Calc::Date_to_Text($year, $month, 01);

# R01-003 Moved here. if leap year, change the max days for Feb
$maxdays[2] = 29 if Date::Calc::leap_year($year);

my @dateText = split(" ", $a);                     # split on spaces
my @Literal = split("-", $dateText[1]);            # split on '-'
$_ = $dateText[0];                              # set to day of week
my @dayArray = ('Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa');  # Set the day array

#set the day hash
my %days = ("Sun"=>0, "Mon"=>1, "Tue"=>2, "Wed"=>3, "Thu"=>4, "Fri"=>5, "Sat"=>6);
my $day = $days{$_};                          # get the day number
my $on;

my $ndx = 0;                                  # initialize day number
my $m = new MainWindow;                    # start a new window
$m->configure(-title=>"$Literal[1] $Literal[2]");  # set the window title
# R01-002 - Changed Row from 7 to 8
for (my $row = 0; $row < 8; $row++) {         # create calendar rows
    for (my $col = 0; $col < 7; $col++) {     # create calendar columns
        $b = $m->Button(-width=>2,         # Create Button
                 -activeforeground=>'white', # format the foreground
                 -activebackground=>'blue'); # also the background
        $b->grid(-row=>$row, -column=>$col);  # put this in the right place
        if ($row eq 0) {                   # if first row,
           $b->configure(-text=>$dayArray[$col], # disable the button
                                        -state=>'disabled');
        } else {
           if ($col eq $day && $row eq 1) { $on = 1; $ndx = 1 } # Turn on switch if start of day
           if (int($ndx) > int($maxdays[$month])) { $on = 0  }  # Turn off switch if all days are displayed
           if ($on) {
              $b->configure(-text=>$ndx++);  # put the day on the button
                                             # and add one to the day
              $b->bind("<ButtonPress>",      # If the button is presssed
                     [\&DateSelected, $year, $month]);  # execute the Date Selected subroutine
           } else {
              $b->configure(-state=>'disabled'); # if switch if off, disable button
           }
       }
       if ($col eq 0) {                   #if first column, this is Sunday
          $b->configure(-fg=>'red',   # configure button
                          -activeforeground=>'white',
                          -activebackground=>'red');
       }
    }
    if (int($ndx) > int($maxdays[$month])) { last  }  # if all days displayed. exit
}

MainLoop;  #Loop

sub DateSelected {                        # execute when button is pressed
    my ($w, $year, $month)  = @_;         # get the parms (widget, year and month)
    my $text = $w->cget(-text);              # get the text on the button
    print "Date Selected: $text\t$year\t$month\n";  # display information
}