IkiWiki/Plugin/calendar.pm



#! /usr/bin/perl
# Copyright (c) 2006, 2007 Manoj Srivastava <srivasta@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

require 5.002;
package IkiWiki::Plugin::calendar;

use warnings;
use strict;
use IkiWiki 3.00;
use Time::Local;
use POSIX;

my %cache;
my %linkcache;
my $time=time;
my @now=localtime($time);

sub import {
    hook(type => "getsetup", id => "calendar", call => \&getsetup);
    hook(type => "needsbuild", id => "calendar", call => \&needsbuild);
    hook(type => "preprocess", id => "calendar", call => \&preprocess);
}

sub getsetup () {
    return
        plugin => {
            safe => 1,
            rebuild => undef,
        },
        archivebase => {
            type => "string",
            example => "archives",
            description => "base of the archives hierarchy",
            safe => 1,
            rebuild => 1,
        },
}

sub is_leap_year (@) {
    my %params=@_;
    return ($params{year} % 4 == 0 && (($params{year} % 100 != 0) || $params{year} % 400 == 0));
}

sub month_days {
    my %params=@_;
    my $days_in_month = (31,28,31,30,31,30,31,31,30,31,30,31)[$params{month}-1];
    if ($params{month} == 2 && is_leap_year(%params)) {
        $days_in_month++;
    }
    return $days_in_month;
}

sub format_month (@) {
    my %params=@_;

    my $pagespec = $params{pages};
    my $year     = $params{year};
    my $month    = $params{month};
    my $pmonth   = $params{pmonth};
    my $nmonth   = $params{nmonth};
    my $pyear    = $params{pyear};
    my $nyear    = $params{nyear};

    my @list;
    my $calendar="\n";

    # When did this month start?
    my @monthstart = localtime(timelocal(0,0,0,1,$month-1,$year-1900));

    my $future_dom = 0;
    my $today      = 0;
    if ($year == $now[5]+1900 && $month == $now[4]+1) {
        $future_dom = $now[3]+1;
        $today      = $now[3];
    }

    # Find out month names for this, next, and previous months
    my $monthname=POSIX::strftime("%B", @monthstart);
    my $pmonthname=POSIX::strftime("%B", localtime(timelocal(0,0,0,1,$pmonth-1,$pyear-1900)));
    my $nmonthname=POSIX::strftime("%B", localtime(timelocal(0,0,0,1,$nmonth-1,$nyear-1900)));

    my $archivebase = 'archives';
    $archivebase = $config{archivebase} if defined $config{archivebase};
    $archivebase = $params{archivebase} if defined $params{archivebase};
  
    # Calculate URL's for monthly archives.
    my ($url, $purl, $nurl)=("$monthname",'','');
    if (exists $cache{$pagespec}{"$year/$month"}) {
        $url = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$year/".sprintf("%02d", $month),
            linktext => " $monthname ");
    }
    add_depends($params{page}, "$archivebase/$year/".sprintf("%02d", $month));
    if (exists $cache{$pagespec}{"$pyear/$pmonth"}) {
        $purl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$pyear/" . sprintf("%02d", $pmonth),
            linktext => " $pmonthname ");
    }
    add_depends($params{page}, "$archivebase/$pyear/".sprintf("%02d", $pmonth));
    if (exists $cache{$pagespec}{"$nyear/$nmonth"}) {
        $nurl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$nyear/" . sprintf("%02d", $nmonth),
            linktext => " $nmonthname ");
    }
    add_depends($params{page}, "$archivebase/$nyear/".sprintf("%02d", $nmonth));

    # Start producing the month calendar
    $calendar=<<EOF;
<table class="month-calendar">
    <caption class="month-calendar-head">
    $purl
    $url
    $nurl
    </caption>
    <tr>
EOF

    # Suppose we want to start the week with day $week_start_day
    # If $monthstart[6] == 1
    my $week_start_day = $params{week_start_day};

    my $start_day = 1 + (7 - $monthstart[6] + $week_start_day) % 7;
    my %downame;
    my %dowabbr;
    for my $dow ($week_start_day..$week_start_day+6) {
        my @day=localtime(timelocal(0,0,0,$start_day++,$month-1,$year-1900));
        my $downame = POSIX::strftime("%A", @day);
        my $dowabbr = POSIX::strftime("%a", @day);
        $downame{$dow % 7}=$downame;
        $dowabbr{$dow % 7}=$dowabbr;
        $calendar.= qq{\t\t<th class="month-calendar-day-head $downame">$dowabbr</th>\n};
    }

    $calendar.=<<EOF;
    </tr>
EOF

    my $wday;
    # we start with a week_start_day, and skip until we get to the first
    for ($wday=$week_start_day; $wday != $monthstart[6]; $wday++, $wday %= 7) {
        $calendar.=qq{\t<tr>\n} if $wday == $week_start_day;
        $calendar.=qq{\t\t<td class="month-calendar-day-noday $downame{$wday}">&nbsp;</td>\n};
    }

    # At this point, either the first is a week_start_day, in which case
    # nothing has been printed, or else we are in the middle of a row.
    for (my $day = 1; $day <= month_days(year => $year, month => $month);
         $day++, $wday++, $wday %= 7) {
        # At tihs point, on a week_start_day, we close out a row,
        # and start a new one -- unless it is week_start_day on the
        # first, where we do not close a row -- since none was started.
        if ($wday == $week_start_day) {
            $calendar.=qq{\t</tr>\n} unless $day == 1;
            $calendar.=qq{\t<tr>\n};
        }
        
        my $tag;
        my $mtag = sprintf("%02d", $month);
        if (defined $cache{$pagespec}{"$year/$mtag/$day"}) {
            if ($day == $today) {
                $tag='month-calendar-day-this-day';
            }
            else {
                $tag='month-calendar-day-link';
            }
            $calendar.=qq{\t\t<td class="$tag $downame{$wday}">};
            $calendar.=htmllink($params{page}, $params{destpage}, 
                                pagename($linkcache{"$year/$mtag/$day"}),
                                "linktext" => "$day");
            push @list, pagename($linkcache{"$year/$mtag/$day"});
            $calendar.=qq{</td>\n};
        }
        else {
            if ($day == $today) {
                $tag='month-calendar-day-this-day';
            }
            elsif ($day == $future_dom) {
                $tag='month-calendar-day-future';
            }
            else {
                $tag='month-calendar-day-nolink';
            }
            $calendar.=qq{\t\t<td class="$tag $downame{$wday}">$day</td>\n};
        }
    }

    # finish off the week
    for (; $wday != $week_start_day; $wday++, $wday %= 7) {
        $calendar.=qq{\t\t<td class="month-calendar-day-noday $downame{$wday}">&nbsp;</td>\n};
    }
    $calendar.=<<EOF;
    </tr>
</table>
EOF

    # Add dependencies to update the calendar whenever pages
    # matching the pagespec are added or removed.
    add_depends($params{page}, $params{pages});
    # Explicitly add all currently linked pages as dependencies, so
        # that if they are removed, the calendar will be sure to be updated.
        add_depends($params{page}, join(" or ", @list));

    return $calendar;
}

sub format_year (@) {
    my %params=@_;

    my $pagespec = $params{pages};
    my $year     = $params{year};
    my $month    = $params{month};
    my $pmonth   = $params{pmonth};
    my $nmonth   = $params{nmonth};
    my $pyear    = $params{pyear};
    my $nyear    = $params{nyear};

    my $calendar="\n";

    my $future_month = 0;
    $future_month = $now[4]+1 if ($year == $now[5]+1900);

    my $archivebase = 'archives';
    $archivebase = $config{archivebase} if defined $config{archivebase};
    $archivebase = $params{archivebase} if defined $params{archivebase};

    # calculate URL's for previous and next years
    my ($url, $purl, $nurl)=("$year",'','');
    if (exists $cache{$pagespec}{"$year"}) {
        $url = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$year",
            linktext => "$year");
    }
    add_depends($params{page}, "$archivebase/$year");
    if (exists $cache{$pagespec}{"$pyear"}) {
        $purl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$pyear",
            linktext => "\&larr;");
    }
    add_depends($params{page}, "$archivebase/$pyear");
    if (exists $cache{$pagespec}{"$nyear"}) {
        $nurl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$nyear",
            linktext => "\&rarr;");
    }
    add_depends($params{page}, "$archivebase/$nyear");

    # Start producing the year calendar
    $calendar=<<EOF;
<table class="year-calendar">
    <caption class="year-calendar-head">
    $purl
    $url
    $nurl
    </caption>
    <tr>
        <th class="year-calendar-subhead" colspan="$params{months_per_row}">Months</th>
    </tr>
EOF

    for ($month = 1; $month <= 12; $month++) {
        my @day=localtime(timelocal(0,0,0,15,$month-1,$year-1900));
        my $murl;
        my $monthname = POSIX::strftime("%B", @day);
        my $monthabbr = POSIX::strftime("%b", @day);
        $calendar.=qq{\t<tr>\n}  if ($month % $params{months_per_row} == 1);
        my $tag;
        my $mtag=sprintf("%02d", $month);
        if ($month == $params{month}) {
            if ($cache{$pagespec}{"$year/$mtag"}) {
                $tag = 'this_month_link';
            }
            else {
                $tag = 'this_month_nolink';
            }
        }
        elsif ($cache{$pagespec}{"$year/$mtag"}) {
            $tag = 'month_link';
        } 
        elsif ($future_month && $month >= $future_month) {
            $tag = 'month_future';
        } 
        else {
            $tag = 'month_nolink';
        }

        if ($cache{$pagespec}{"$year/$mtag"}) {
            $murl = htmllink($params{page}, $params{destpage}, 
                "$archivebase/$year/$mtag",
                linktext => "$monthabbr");
            $calendar.=qq{\t<td class="$tag">};
            $calendar.=$murl;
            $calendar.=qq{\t</td>\n};
        }
        else {
            $calendar.=qq{\t<td class="$tag">$monthabbr</td>\n};
        }
        add_depends($params{page}, "$archivebase/$year/$mtag");

        $calendar.=qq{\t</tr>\n} if ($month % $params{months_per_row} == 0);
    }

    $calendar.=<<EOF;
</table>
EOF

    return $calendar;
}

sub preprocess (@) {
    my %params=@_;
    $params{pages} = "*"            unless defined $params{pages};
    $params{type}  = "month"        unless defined $params{type};
    $params{month} = sprintf("%02d", $params{month}) if defined  $params{month};
    $params{week_start_day} = 0     unless defined $params{week_start_day};
    $params{months_per_row} = 3     unless defined $params{months_per_row};

    if (! defined $params{year} || ! defined $params{month}) {
        # Record that the calendar next changes at midnight.
        $pagestate{$params{destpage}}{calendar}{nextchange}=($time
            + (60 - $now[0])        # seconds
            + (59 - $now[1]) * 60       # minutes
            + (23 - $now[2]) * 60 * 60  # hours
        );
        
        $params{year}  = 1900 + $now[5] unless defined $params{year};
        $params{month} = 1    + $now[4] unless defined $params{month};
    }
    else {
        delete $pagestate{$params{destpage}}{calendar};
    }

    # Calculate month names for next month, and previous months
    my $pmonth = $params{month} - 1;
    my $nmonth = $params{month} + 1;
    my $pyear  = $params{year}  - 1;
    my $nyear  = $params{year}  + 1;

    # Adjust for January and December
    if ($params{month} == 1) {
        $pmonth = 12;
        $pyear--;
    }
    if ($params{month} == 12) {
        $nmonth = 1;
        $nyear++;
    }

    $params{pmonth}=$pmonth;
    $params{nmonth}=$nmonth;
    $params{pyear} =$pyear;
    $params{nyear} =$nyear;

    my $calendar="\n";
    my $pagespec=$params{pages};
    my $page =$params{page};

    if (! defined $cache{$pagespec}) {
        foreach my $p (keys %pagesources) {
            next unless pagespec_match($p, $pagespec);
            my $mtime = $IkiWiki::pagectime{$p};
            my $src   = $pagesources{$p};
            my @date  = localtime($mtime);
            my $mday  = $date[3];
            my $month = $date[4] + 1;
            my $year  = $date[5] + 1900;
            my $mtag  = sprintf("%02d", $month);

            # Only one posting per day is being linked to.
            $linkcache{"$year/$mtag/$mday"} = "$src";
            $cache{$pagespec}{"$year"}++;
            $cache{$pagespec}{"$year/$mtag"}++;
            $cache{$pagespec}{"$year/$mtag/$mday"}++;
        }
    }

    if ($params{type} =~ /month/i) {
        $calendar=format_month(%params);
    }
    elsif ($params{type} =~ /year/i) {
        $calendar=format_year(%params);
    }

    return "\n<div><div class=\"calendar\">$calendar</div></div>\n";
} #}}

sub needsbuild (@) {
    my $needsbuild=shift;
    foreach my $page (keys %pagestate) {
        if (exists $pagestate{$page}{calendar}{nextchange}) {
            if ($pagestate{$page}{calendar}{nextchange} <= $time) {
                # force a rebuild so the calendar shows
                # the current day
                push @$needsbuild, $pagesources{$page};
            }
            if (exists $pagesources{$page} && 
                grep { $_ eq $pagesources{$page} } @$needsbuild) {
                # remove state, will be re-added if
                # the calendar is still there during the
                # rebuild
                delete $pagestate{$page}{calendar};
            }
        }
    }
}

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