#!/usr/bin/perl

#(c) 2005 Christopher Uriarte
# rssflckr.cgi - parses a flckr atom feed to show the most recent MAXENTRIES, links and date added

use LWP::Simple;
use XML::Parser;

####
#Static Values
####
$MAXENTRIES = 5;
$url = 'http://www.flickr.com/services/feeds/photos_public.gne?id=64426228@N00&format=atom_03';
#Tag Tracker
my $thistag;
#Track if we're in an <entry> block
my $entryflag;
#count the number of entries
my $count = 0;

####
#Retrieve XML Date
####
my $data;
$SIG{ALRM} = \&timed_out;
eval	{
	alarm(30);
	#get the base URL
	$data = get($url) || die "Can't retrieve feed at $url";
	alarm(0);
	};	

sub timed_out	{
	my $time; 
	$time = localtime();
	die "$time: Timed out while accessing feed at $url\n";
}
	



my $parser = new XML::Parser(ErrorContext => 2);
$parser->setHandlers(Start => \&start_handler,
                      End   => \&end_handler,
                      Char  => \&char_handler);
  
$parser->parse($data);

#We start here when we encounter an HTML Tag
sub start_handler {
     	my $expat = $_[0];
	my $element = $_[1];
	#print "Encountered element $element\n";

	#If we enter an <entry> tag, we have a new element
	#Increase the county by 1 and set the entry flag to 1
	if ($element eq "entry")
		{
		$count++;
		$entryflag = 1;
		#print "Count is now $count and entryflag is set to $entryflag.\n";
		}

	if ($element eq "title" && $entryflag == 1)
		{
		$thistag = "title";
		}


	#Grab the title and href element of the second "link" tag
	#exclude service.edit links, we want the "alternate" tag link
	#print "Encountering Element=$element,entryflag=$entryflag,dollar_1,2,3=$_[1],$_[2],$_[3] \n";
	if ( ($element eq "link") and ($entryflag == 1) and ($_[3] eq "alternate") )
		{
		$ENTRIES{$count}->{link} = $_[7];
		#print "Link: $_[7]\n";
		}


	if ($element eq "issued" && $entryflag == 1)
		{
		$thistag = "issued";
		#print "Added: $_";
		}
}


#This is where we handle the values within the tag
sub char_handler {
     	my ($p, $data) = @_;
	
	#print the modified date
	if ($thistag eq "issued" && $entryflag == 1)
		{
		#Get the first 11 Chars of the date, that's all we care about
		$date = substr($data,0,10);
		#print "$date\n";
		$ENTRIES{$count}->{date} = $date;
		$thistag = "";
		}

	if ( ($thistag eq "title") and ($entryflag == 1) )
		{
		$ENTRIES{$count}->{title} = $data;
		$thistag = "";
		}

	1;

}


sub end_handler {
    	my $expat = shift; 
	my $element = shift;

	#If we're at the end of an <entry> block, clear the entry flag
	if ($element eq "entry")
		{
		$entryflag = 0;
		#print "\n\n";
		}

	1;
}



#Determine how many entries to display

#If our set maximum amt of entries is less than what we encountered
#we only display up to $MAXENTRIES 
if ($MAXENTRIES < $count)
	{
	$MAX = $MAXENTRIES;
	}
#Otherwise, we display what we encountered
else	
	{
	$MAX = $count;
	}

#Map through the %ENTRIES hash from 1 to $MAX  to display the links
for ($c=1; $c<=$MAX; $c++)
	{
	#print "Loop is $c, count is $count\n";
	$title = $ENTRIES{$c}->{title};
	$link = $ENTRIES{$c}->{link};
	$date = $ENTRIES{$c}->{date};
	print "-<A HREF=\"$link\">$title</A> (added: $date)<BR>\n";
	}