#!/usr/local/bin/perl
# 
# Calendar Script
#
# Matt Kruse
# http://mkruse.netexpress.net/
#

$|=1;
print "Content-type: text/html\n\n";

#####################################################################
#
# Configuration Parameters
#
#####################################################################

$base_dir = "/usr/local/apache/htdocs/calendar/";
$template_dir = "/usr/local/apache/htdocs/calendar/templates/";
$vars{"CGI"} = "http://rshweb.com/calendar/calendar.cgi";
$vars{"BASE"} = "http://rshweb.com/calendar/";

$calendar_file = $base_dir . "calendar_events.txt";
$textcolor_today = "ff0000";
$cell_width=100;
$MonSunWeek = 0;

#####################################################################
# END CONFIG
#####################################################################

use lib ".";
unshift(@INC,$base_dir);
require "parse_template.pl";
&INITIALIZE;
&ReadParse;

#####################################################################
#
# Decide what to do based on the ACTION parameter
#
#####################################################################
if ($in{"ACTION"} eq "VIEWDAY") {
	&VIEWDAY;
	}
elsif ($in{"ACTION"} eq "ADD") {
	&ADD;
	}
else {
	&DISPLAY;
	}
exit(0);

#####################################################################
#
# DISPLAY()
#
# Display the calendar
#
#####################################################################
sub DISPLAY {
	&read_cal_data;
	$in{'Month'} = $in{Month} || $month;
	$in{'Year'} = $in{Year} || $year;
	$in{'Type'} = $DefaultType; 

	$xmonth = @months[int($in{'Month'})-1];
	$lastyear  = $in{Year}-1;
	$nextyear  = $in{Year}+1;
	$lastmonth = $in{Month}-1;
	$nextmonth = $in{Month}+1;
	if ($lastmonth < 1) { $lastmonth=12; }
	if ($nextmonth > 12){ $nextmonth=1;  }

	&PerpetualCalendar(int($in{'Month'}),1,int($in{'Year'}));

	# Create the calendar output into a variable
	# ------------------------------------------
	$calendar = <<"END";
<TABLE BORDER=6 CELLPADDING=0>
<TR>
	<TH COLSPAN=7 VALIGN=TOP>
	<A HREF="$vars{CGI}?Year=$in{Year}&Month=$lastmonth"><IMG SRC="images/month_left.gif" BORDER=0 ALIGN=LEFT></A>
	<A HREF="$vars{CGI}?Year=$in{Year}&Month=$nextmonth"><IMG SRC="images/month_right.gif" BORDER=0 ALIGN=RIGHT></A>
	<IMG SRC="images/$xmonth.gif">
	<BR>
	<FONT SIZE="+2">
	<A HREF="$vars{CGI}?Year=$lastyear&Month=$in{Month}">&lt;</A>&nbsp;&nbsp;
	$in{Year}
	&nbsp;&nbsp;<A HREF="$vars{CGI}?Year=$nextyear&Month=$in{Month}">&gt;</A>
	</FONT>
	</TH>
</TR>
<TR>
	<TH WIDTH=$cell_width>Sunday</TH>
	<TH WIDTH=$cell_width>Monday</TH>
	<TH WIDTH=$cell_width>Tuesday</TH>
	<TH WIDTH=$cell_width>Wednesday</TH>
	<TH WIDTH=$cell_width>Thursday</TH>
	<TH WIDTH=$cell_width>Friday</TH>
	<TH WIDTH=$cell_width>Saturday</TH>
</TR>
<TR>
END
	if ($perp_dow > 0) { $calendar .= "<TD COLSPAN=$perp_dow >&nbsp;</TD>"; }
	foreach $key (1..$perp_eom) {
		$calendar .= "<TD VALIGN=TOP>";
		if (($in{'Year'} == $year) && ($in{'Month'} == $month) && ($key == $mday)) {
			$calendar .= "<FONT COLOR=\"#$textcolor_today\">";
			$calendar .=  "<P><BIG><STRONG>$key</STRONG></BIG>";
		}
		else {
			$calendar .=  "<FONT><P><BIG>$key</BIG>";
		}
		$perp_sofar++;
		$perp_togo -= 1;
		$calendar .=  "</FONT>\n<FONT SIZE=\"-2\"><br>";
		$xdatestamp = sprintf("%4.4d%2.2d%2.2d",$in{Year},$in{Month},$key);
		foreach (0 .. 3) {
			next unless ${$events{$xdatestamp}{labels}}[$_];
			$calendar .= sprintf("%20.20s<BR>\n",${$events{$xdatestamp}{labels}}[$_]);
			}
		$xcount = $#{$events{$xdatestamp}{labels}};
		$xdatestamp = sprintf("0000%2.2d%2.2d",$in{Month},$key);
		if ($xcount < 3) {
			foreach (0 .. 2-$xcount) {
				$calendar .= sprintf("%20.20s<BR>\n",${$events{$xdatestamp}{labels}}[$_]);
				}
			}
		$xcount = $xcount + $#{$events{$xdatestamp}{labels}};
	
		if ( $xcount > 2) {
			$calendar .=  "...\n";
			}
		$xdatestamp = sprintf("%4.4d%2.2d%2.2d",$in{Year},$in{Month},$key);
		$calendar .=  "</FONT>\n<A HREF=\"javascript:viewday('$xdatestamp')\"><IMG SRC=\"images/curl.gif\" ALIGN=RIGHT BORDER=0></A></TD>\n";
		$weekday = ($key+$perp_dow)-(int(($key+$perp_dow)/7)*7);
		if (($weekday == 0) && !($key == $perp_eom)) {
			$calendar .=  "\n</TR><TR>\n";
		}
	}
	if ($weekday > 0) {
		$leftover = 7-$weekday;
		$calendar .=  "<TD COLSPAN=$leftover ><P>&nbsp;</TD>";
	}
	$calendar .= "</TR>\n</TABLE>\n";
	
	# Load the template and do the replace
	# ------------------------------------
	$template = &load_template("${template_dir}calendar.html");
	$vars{"CALENDAR"} = $calendar;
	
	$template = &parse_template($template, \%vars);
	print $template;
	
	exit;
	} #end of DISPLAY


#####################################################################
#
# VIEWDAY()
#
# Display a single day's events
#
#####################################################################
sub VIEWDAY {
	&read_cal_data;
	
	($year,$month,$date) = ($in{DATE} =~ /(....)(..)(..)/);
	$xmonth = $months[int($month)-1];
	
	$vars{"TITLE"} = "$xmonth $date, $year";
	
	$vars{"EVENTS"} = "";
	$xdatestamp = sprintf("%4.4d%2.2d%2.2d",$year,$month,$date);
	foreach (0 .. $#{$events{$xdatestamp}{desc}}) {
		$vars{"EVENTS"} .= "<LI>${$events{$xdatestamp}{desc}}[$_]<BR>\n";
		}
	$xdatestamp = sprintf("0000%2.2d%2.2d",$month,$date);
	foreach (0 .. $#{$events{$xdatestamp}{desc}}) {
		$vars{"EVENTS"} .= "<LI>${$events{$xdatestamp}{desc}}[$_]<BR>\n";
		}
	
	$template = &load_template("${template_dir}calendar_day.html");
	$template = &parse_template( $template, \%vars );
	$template = &parse_template( $template, \%in );
	print $template;
	
	exit;
	} #end of VIEWDAY

#####################################################################
#
# ADD()
#
# Add an entry
#
#####################################################################
sub ADD {	
	$in{description} =~ s|[\r\n]| |gs;
	
	open(OUT,">> $calendar_file") || die "Can't open $calendar_file for writing!";
	print OUT "$in{DATE}|$in{heading}|$in{description}\n";
	close(OUT);
	
	print <<"END";
<HTML><HEAD>
<META HTTP-EQUIV="refresh" CONTENT="0;URL=$vars{CGI}?ACTION=VIEWDAY&DATE=$in{DATE}">
</HEAD>
</HTML>

END
	exit(0);
	} #end of ADD
	
#####################################################################
#
# Initialize variables
#
#####################################################################
sub INITIALIZE {
	@months = (January,February,March,April,May,June,July,August,September,October,November,December);
	@shortmonths = (Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec);
	@days =(Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday);
	@shortdays = (Sun,Mon,Tue,Wed,Thu,Fri,Sat);

	# Current date and stuff

	$time = time;
	($mday,$month,$year) = (localtime($time))[3,4,5];
	$month = $month+1;
	$year = $year+1900;
	$datestamp = sprintf("%4.4d%2.2d%2.2d",$year,$month,$mday);
	
	}


#####################################################################
#
# Read in calendar data file
#
#####################################################################
sub read_cal_data {
	open(IN,"$calendar_file") || die "Can't open $calendar_file";
	while (<IN>) {
		chomp;
		next unless /^\d/;
		($xdatestamp,$label,$desc) = split(/\|/,$_,3);
		push(@{$events{$xdatestamp}{desc}},$desc);
		push(@{$events{$xdatestamp}{labels}},$label);
		}
	close(IN);
	
	}

#####################################################################
#
# Parse input
#
#####################################################################
sub ReadParse {
 local (*in) = @_ if @_;  local ($i, $loc, $key, $val);
 if ($ENV{'REQUEST_METHOD'} eq "GET") { $in = $ENV{'QUERY_STRING'};} 
 elsif ($ENV{'REQUEST_METHOD'} eq "POST")
      {read(STDIN,$in,$ENV{'CONTENT_LENGTH'});}
 @in = split(/&/,$in);
 foreach $i (0 .. $#in) {
  $in[$i] =~ s/\+/ /g;    ($key, $val) = split(/=/,$in[$i],2);
  $key =~ s/%(..)/pack("c",hex($1))/ge;
  $val =~ s/%(..)/pack("c",hex($1))/ge;
  $in{$key} .= "\0" if (defined($in{$key})); 
  $in{$key} .= $val;  
  }  
 return 1; 
 }


#####################################################################
#
# Calendar logic
#
#####################################################################
sub PerpetualCalendar {
	# This perpetual calendar routine provides accurate day/date
	# correspondences for dates from 1601 to 2899 A.D.  It is based on
	# the Gregorian calendar, so be aware that early correspondences
	# may not always be historically accurate.  The Gregorian calendar
	# was adopted by the Italian states, Portugal and Spain in 1582,
	# and by the Catholic German states in 1583.  However, it was not
	# adopted by the Protestant German states until 1699, by England
	# and its colonies until 1752, by Sweden until 1753, by Japan
	# until 1873, by China until 1912, by the Soviet Union until 1918,
	# and by Greece until 1923.
	($perp_mon,$perp_day,$perp_year) = @_;
	%day_counts =
	  (1,0,2,31,3,59,4,90,5,120,6,151,7,181,
	  8,212,9,243,10,273,11,304,12,334);
	$perp_days = (($perp_year-1601)*365)+(int(($perp_year-1601)/4));
	$perp_days += $day_counts{$perp_mon};
	$perp_days += $perp_day;
	$perp_sofar = $day_counts{$perp_mon};
	$perp_sofar += $perp_day;
	$perp_togo = 365-$perp_sofar;
	if (int(($perp_year-1600)/4) eq (($perp_year-1600)/4)) {
		$perp_togo++;
		if ($perp_mon > 2) {
			$perp_days++;
			$perp_sofar++;
			$perp_togo -= 1;
		}
	}
	foreach $key (1700,1800,1900,2100,2200,2300,2500,2600,2700) {
		if ((($perp_year == $key) && ($perp_mon > 2))
		  || ($perp_year > $key)) {
			$perp_days -= 1;
		}
	}
	$perp_dow = $perp_days - (int($perp_days/7)*7);
	if ($perp_dow == 7) { $perp_dow = 0; }
	if ($MonSunWeek) {
		$perp_dow -= 1;
		if ($perp_dow == -1) { $perp_dow = 6; }
	}
	$perp_eom = 31;
	if (($perp_mon == 4) || ($perp_mon == 6)
	  || ($perp_mon == 9) || ($perp_mon == 11)) {
		$perp_eom = 30;
	}
	if (($perp_mon == 2)) {
		$perp_eom = 28;
	}
	if ((int(($perp_year-1600)/4) eq (($perp_year-1600)/4))
	  && ($perp_mon == 2)) {
		$perp_eom = 29;
	}
	foreach $key (1700,1800,1900,2100,2200,2300,2500,2600,2700) {
		if ($perp_year == $key) {
			if ($perp_mon == 1) {
				$perp_togo -= 1;
			}
			elsif ($perp_mon == 2) {
				$perp_togo -= 1;
				$perp_eom = 28;
			}
			else {
				$perp_sofar -= 1;
			}
		}
	}
}