#!/usr/bin/perl

# Local configuration
$use_auth = 1;
my $username = "SOMEBODY";
my $password = "SOMEPASSWORD";

my $owner = "SOME@EMAIL.ADDRESS";

$ENV{'QUERY_STRING'} = 'user=$username';
my $no_http = 1;

# Set this to avoid querying LJ - for testing only!
my $cache_override = 0;

# Also see $limit, $cache_folder, etc below.

############################################################################
#
# Friend RSS Generator
# Written by Ben Gutierrez (nullmemoirs)
# Local (non-CGI) operation and updates by Daniel Jacobowitz <drow@false.org>
# 
# Usage:
# http://www.domain.com/cgi-bin/ljfriendfeed.pl?user=username
# http://www.domain.com/cgi-bin/ljfriendfeed.pl?user=username&limit=5
# http://www.domain.com/cgi-bin/ljfriendfeed.pl?user=username&friend=stalked1&friend=stalked2
# http://www.domain.com/cgi-bin/ljfriendfeed.pl?user=username&skip=5
# http://www.domain.com/cgi-bin/ljfriendfeed.pl?user=username&rmfriend=unwanted
# 
# Installation: Very easy. Just drop it in your cgi-bin. Needs only 
# LWP::Simple
#
# Creating a cache folder is highly recommended. Make sure it is writeable
# by the web server.
#
# Email me at mowgli@mowgli.org
# 
############################################################################

# Uncomment for LWP::Simple logging.
# use LWP::Debug qw(+);
use LWP::Simple qw(get mirror $ua);

$ua->agent("ljfriendfeed.pl; $owner; ");

if ($use_auth) {
    $ua->credentials ('www.livejournal.com:80', 'lj', $username, $password);
}

# Use this to set the limit
my $limit = 1000;

# Uncomment this to use a cache (Recommended highly!)
# my $cache_folder = '/home/user/lj';

my $cache_enabled = (defined($cache_folder) && -d $cache_folder && -w $cache_folder);

if (!$no_http) {
    print "Content-Type: text/xml; charset=utf-8\n\n";
}

# So far, only works if there is a user.
if ($ENV{'QUERY_STRING'} =~ /user=(\w+)/ ) {
    make_feed($1);
} else { print error_message('no user') and die; };

# Primary function
# Usage: makefeed('user_name');
sub make_feed{
    my $user = shift;
    my @friends = friends($user);

    # RSS Beginning
    print "<!-- Friend RSS Genereator by Ben Gutierrez (nullmemoirs)
Download it at http://www.mowgli.org/lj/ljfriendfeed.pl -->
<rss version=\"2.0\" xmlns:lj='http://www.livejournal.org/rss/lj/1.0/'>
<channel>
  <title>Friends of $user</title>
  <link>http://www.livejournal.com/users/$user/friends</link>
  <description>News Feed of all $user's friends.</description>
  <generator>http://www.mowgli.org/cgi-bin/ljfriendfeed.pl</generator>\n";

    print all_feeds(@friends);

    #RSS End
    print "</channel>\n</rss>";
}

# Returns all friends for user, plus any in the url.
# Usage: friends('user_name')
sub friends {
    my $user = shift;

    # The user data is always generated new.
    my $user_info = get "http://www.livejournal.com/users/$user/data/foaf";

    if (!$user_info) { print error_message('no server') and die; }

    # Friends of user
    my @user_friends;

    while ($user_info =~ s/<foaf:nick>(\w*?)</foaf:nick>/) {
	my $friend = $1;
	next if ($ENV{'QUERY_STRING'} =~ /rmfriend=($friend)/);
	push @user_friends, $friend;
    }

    # Friends in the url.
    if (my @q_friends = $ENV{'QUERY_STRING'} =~ /[^m]friend=(\w+)/g) {
	push @user_friends, @q_friends;
    }

    # First friend is the user. Baleeted!
    shift @user_friends;

    return @user_friends;
}

# Get friends, get feeds for each,
# sort them, return them.
# Usage: all_feeds(@friend_list)
sub all_feeds {
    my @friends = @_;
    my @feeds;
    push @feeds, news_feed($_) foreach(@friends);

    @feeds = sort by_date @feeds;

    # Skip feature
    @feeds = splice(@feeds, $1) if ($ENV{'QUERY_STRING'} =~ /skip=(\d+)/);

    # Set the appropriate limit.
    $limit = $1 if ($ENV{'QUERY_STRING'} =~ /limit=(\d+)/ && $1 < $limit);

    @feeds = @feeds[0 .. ($limit-1)];

    return @feeds;
}

# Gets a feed for one user
# Usage: news_feed('user_name')
sub news_feed {
    my $user = shift;
    my $rss;
    my $url = "http://www.livejournal.com/users/$user/data/rss";
    
    if ($use_auth) {
        $url .= "?auth=digest";
        # Around 2006-01-18 LiveJournal switched to using redirects...
        if ($user =~ /^_/) {
          $ua->credentials ("users.livejournal.com:80", 'lj', $username, $password);
        } else {
	  my $tmpuser = $user;
	  $tmpuser =~ s/_/-/g;
          $ua->credentials ("${tmpuser}.livejournal.com:80", 'lj', $username, $password);
        }
    }

    # Use a cache whenever possible.
    if ($cache_enabled) {
	my $local_copy = "$cache_folder/$user.xml";
        if (!$cache_override || !-e $local_copy) {
	    mirror($url, $local_copy);
	}
	$rss = `cat $local_copy`;
    } else {
	$rss = get($url);
    }

    # Just return if there are no feeds
    if (!$rss) { return; }
    my @items;

    # Gets each item and sticks it in an array.
    while($rss =~ /(<item>.*?<\/item>)/sg) {
	my $item = $1;

	# If there isn't a title, make one based on description.
	unless ($item =~ s/<title>(.*)<\/title>/<title>$user - $1<\/title>/) {
	    $item =~ /<description>(.*)<\/description>/s;
	    my $content = $1;
	    $content =~ s/&lt;br \/&gt;.*/./g;    # Remove everything after first <br />
	    $content =~ s/&lt;.*?&gt;//g;         # Remove tags (may be assuming too much here)
	    $content =~ s/(.+?[\.\n!\?]).*/$1/sg; # Remove everything after end of first sentance

	    # Insert title after pubDate
	    $item =~ s/<\/pubDate>/<\/pubDate>\n<title>$user - $content<\/title>/;
	}
	push @items, $item;
    }

    return @items;
}

# Sorting function for items based on date.
sub by_date {
    $a =~ /<pubDate>.* (\d\d) (\w+) (\d{4}) ([\d:]+).*<\/pubDate>/;
    my $mon = month_to_num($2);
    my $a_date = "$3$mon$1$4";

    $b =~ /<pubDate>.* (\d\d) (\w+) (\d{4}) ([\d:]+) .*<\/pubDate>/;
    $mon = month_to_num($2);
    my $b_date = "$3$mon$1$4";

    $b_date cmp $a_date;
}

# Simple month to number conversion.
sub month_to_num {
    my $month = shift;
    return '01' if ($month eq 'Jan');
    return '02' if ($month eq 'Feb');
    return '03' if ($month eq 'Mar');
    return '04' if ($month eq 'Apr');
    return '05' if ($month eq 'May');
    return '06' if ($month eq 'Jun');
    return '07' if ($month eq 'Jul');
    return '08' if ($month eq 'Aug');
    return '09' if ($month eq 'Sep');
    return '10' if ($month eq 'Oct');
    return '11' if ($month eq 'Nov');
    return '12';
}

# Handle an error or two.
sub error_message {
    my $error_type = shift;
    my $error;
    if ($error_type eq 'no server')  { $error = "Unable to connect to livejournal.com"; }
    elsif ($error_type eq 'no user') { $error = "No user: Use http://www.mowgli.org/cgi-bin/ljfriendfeed.pl?user=username"; }

    my $error_message = "<rss version=\"2.0\">
<channel>
  <title>Empty Feed - $error</title>
</channel>
</rss>";

#  <item>
#    <title>$error</title>
#  </item>

    return $error_message;
}