#!/usr/bin/perl -w

# Blosxom Plugin: calendar
# Author: Todd Larason (jtl@molehill.org) with features by Ben Guaraldi (benj@bluesock.org)
# Version: 0+1i
# Blosxom Home/Docs/Licensing: http://www.raelity.org/blosxom
# Categories plugin Home/Docs/Licensing:
#   http://molelog.molehill.org/blox/Computers/Internet/Web/Blosxom/Calendar/

package calendar;

# --- Configuration Variables ---
# output format
#   'table' -> simple table; simplest, suitable for most people
my $output_format = 'table';

#  names in your preferred language
my @monthname = qw/January February March April May June July
  August September October November December/;
my @weekdayname = qw/Sun Mon Tue Wed Thu Fri Sat/;

# Do you want < and >'s that point to the next and previous 
# month?  If so, leave $nav = 1.  Else, put $nav = 0.
$nav = 1;

# Put the date that you want your calendar to start at.
# (e.g,, Mine starts at 9/1/04, so when you're in September,
# you can't go backwards any more months.)

$calstartdate = "20040901";

(undef, undef, undef, $dd, $mm, $yyyy) = localtime(time);
$calenddate   = sprintf("%04d%02d%02d", $yyyy+1900, $mm+1, $dd);

# The end date is set to the present date.  If you want to have the 
# calendar go into the future, then uncomment this line and enter the
# desired date:
# $calenddate = "20100901";

# --- End of Configuration Section ---

use Time::Local;

$calendar = '';
my %days;

sub report_month_start {
    my ($year, $month, $monthname) = @_;
    my $results = '';
    local $_;
    
    my $prevday, $nextday, $prevmonth, $nextmonth, $prevyear, $nextyear, $tempmonth;

    $prevyear = $nextyear = $year;
    $prevmonth = $month - 1;
    $nextmonth = $month + 1;
    if ($month == 1) {
	$prevmonth = 12;
	$prevyear = $year - 1;
    } elsif ($month == 12) {
	$nextmonth = 1;
	$nextyear = $year + 1;
    }

    $prevday   = days_in_month($prevyear, $prevmonth);
    $nextday   = "01";

    $prevmonth = prependzero($prevmonth);
    $nextmonth = prependzero($nextmonth);
    $tempmonth = prependzero($month);

    if ($output_format eq 'table') {
	$results = qq!<table class="calendar"><tr>!;
	if ($nav) {
	  if ("$prevyear$prevmonth" . "32" > $calstartdate) {
	    $results .= qq!<td rowspan="8" class="calendar_prev_next_link">\n! . 
#		qq!<a href="$blosxom::url/$prevyear/$prevmonth/$prevday" class="prev_next">\&lt;</a>\n! .
		qq!<a href="$blosxom::url/$prevyear/$prevmonth" class="prev_next">\&lt;</a>\n! .
		qq!</td>\n!;
	  } else {
	    $results .= qq!<td rowspan="8" class="calendar_prev_next_link">\n! . 
		qq!&nbsp;&nbsp;</td>\n!;
	  }
	}
	$results .= qq!<th colspan="7" class="calendar_month_head">! .
		qq!<a href="$blosxom::url/$year/$tempmonth" class="prev_next">$monthname $year</a></th>\n!;
	if ($nav) {
	  if ("$nextyear$nextmonth" . "01" <= $calenddate) {
	    $results .= qq!<td rowspan="8" class="calendar_prev_next_link">\n! . 
#		qq!&nbsp;<a href="$blosxom::url/$nextyear/$nextmonth/$nextday" class="prev_next">\&gt;</a>\n! .
		qq!&nbsp;<a href="$blosxom::url/$nextyear/$nextmonth" class="prev_next">\&gt;</a>\n! .
		qq!</td>\n!;
	  } else {
	    $results .= qq!<td rowspan="8" class="calendar_prev_next_link">\n! . 
		qq!&nbsp;&nbsp;</td>\n!;
	  }
	}
	$results .= qq!</tr>\n<tr>\n!;
	$results .= qq!<th class="calendar_day_head">$_</th>\n!
	  foreach (@weekdayname);
	$results .= qq!</tr>\n!;
    } else {
	warn "Unsupported output_format: $output_format";
    }
    return $results;
}

sub report_week_start {
    return qq!<tr>\n! if ($output_format eq 'table');
    return qq!!;
}

sub report_day_noday {
    return qq!<td class="calendar_day_noday">&nbsp;</td>\n!
      if ($output_format eq 'table');
    return qq!!;
}

sub report_day_link {
    my ($year, $month, $day) = @_;
    my $zday, $zmonth;
    $zmonth = prependzero($month);
    $zday = prependzero($day);
    return qq!<td class="calendar_day_link"><a href="$blosxom::url/$year/$zmonth/$zday">$day</a></td>\n!
      if ($output_format eq 'table');
    return qq!!;
}
sub report_day_nolink {
    my ($year, $month, $day) = @_;
    return qq!<td class="calendar_day_nolink">$day</td>\n!
      if ($output_format eq 'table');
    return qq!!;
}
sub report_week_end {
    return qq!</tr>\n! if ($output_format eq 'table');
    return qq!!;
}

sub report_month_end {
    return qq!</table>\n! if ($output_format eq 'table');
    return qq!!;
}

sub days_in_month {
    my ($year, $month) = @_;
    my $days = (31,28,31,30,31,30,31,31,30,31,30,31)[$month-1];
    if ($month == 2 &&
	($year % 4 == 0 &&
	 (($year % 100 != 0) ||
	  ($year % 400 == 0)))) {
	$days++;
    }
    return $days;
}

sub build_calendar {
    my $results;

    my ($now, @now, $monthstart, @monthstart);
    my ($year, $month, $day, $days, $wday, $today);

    $now   	= time;
    @now   	= localtime($now);
    $year  	= $blosxom::path_info_yr ?
			$blosxom::path_info_yr : $now[5] + 1900;
    $month 	= $blosxom::path_info_mo ?
			$blosxom::path_info_mo + 0 : $now[4] + 1;
    $today	= $blosxom::path_info_da ?
			$blosxom::path_info_da + 0 : $now[3];
    $days  	= days_in_month($year, $month);
    # XXX this isn't quite right in the face of daylight savings time
#   $monthstart = $now - ($now[3]-1)*86400;
    $monthstart = timelocal(0,0,0,1,$month-1,$year-1900);
    @monthstart = localtime($monthstart);

    $results = report_month_start($year, $month, $monthname[$month-1]);

    # First, skip over the first partial week (possibly empty)
    # before the month started
    for ($wday = 0; $wday < $monthstart[6]; $wday++) {
	$results .= report_week_start() if ($wday == 0);
	$results .= report_day_noday();
    }

    # now do the month itself
    for ($day = 1; $day <= $days; $day++) {
	$results .= report_week_start() if ($wday == 0);
	if ($days{"$year/$month/$day"}) {
	    $results .= report_day_link($year, $month, $day);
	} else {
	    $results .= report_day_nolink($year, $month, $day);
	}
	if (++$wday == 7) {
	    $wday = 0;
	    $results .= report_week_end();
	}
    }

    # and finish up the last week, if any left
    if ($wday) {
	while (++$wday <= 7) {
	    $results .= report_day_noday();
	}
	$results .= report_week_end();
    }

    $results .= report_month_end();

    return $results;
}

sub start {
    return 1;
}

sub filter {
    my ($pkg, $files) = @_;
    foreach (keys %{$files}) {
	my @date = localtime($files->{$_});
	my $mday  = $date[3];
	my $month = $date[4] + 1;
	my $year  = $date[5] + 1900;
	$days{"$year"}++;
	$days{"$year/$month"}++;
	$days{"$year/$month/$mday"}++;
    }

    $calendar = build_calendar();
}

sub prependzero {
    my $num = $_[0];
    if (length($num) == 1) { return "0$num"; }
    return $num;
}

1;