#!/usr/bin/perl
use strict;
use warnings;

#############################################################################
# Takes rss files from across the internet and sticks them into the database.
# Best ran from cron
#############################################################################
if( -f '/var/run/retrieve_rss.pid'){
	system('kill -9 `cat /var/run/retrieve_rss.pid`');
	system('rm /var/run/retrieve_rss.pid');
}
open(PIDFILE,'>/var/run/retrieve_rss.pid');
print PIDFILE $$,"\n";
close(PIDFILE);

my $DEBUG = defined $ARGV[0] ? $ARGV[0] : 0;

### initial setup
use LWP::Simple;
use XML::RSS;
use DBI;
my $dbh = DBI->connect('DBI:Pg:dbname=DBNAME','DBUSER','DBPASS',{AutoCommit => '0'});

my $sth = $dbh->prepare('select sid,url from rsssites where active is true');
$sth->execute();
while(my ($site_id,$site_url) = $sth->fetchrow_array()){
	eval 'get_links($site_id,$site_url)';
	print $@,"\n" if $@;
}

### disconnect
$sth->finish();
$dbh->disconnect;
### done
unlink '/var/run/retrieve_rss.pid';
1;

### this is for rss sites
sub get_links {

	my ($id,$url) = @_;

	### DEBUG
	print "Getting links for $url\n" if $DEBUG;

	my $document = get($url) || return;
	# clean the string (this fixes some broken rss)
	$document =~ s/\015\012?/\012/g || 1;
	$document =~ s/&(?!(?:[a-zA-Z0-9]+|#\d+);)/&/g || 1;

	# parse a string
	my $rss = new XML::RSS(Style => 'Debug') || return;
	$rss->parse($document) || return;

	# clear out the db, check for a failure, rollback, and move on...
	unless( clear_db($id) ){
		$dbh->rollback;
		return;
	}

	foreach my $item (@{$rss->{'items'}}) {

		my ($title,$link);
		$title = $item->{'title'};
		$link = $item->{'link'};
		chomp($title,$link);
	
		### remove unsightly site specific links
		next if ($title =~ /Customize this feed/i);

		### stick it into the database
		my $sth = $dbh->prepare('insert into rsscontent (cid,title,url) values (?,?,?)');
		$sth->execute($id,$title,$link);
		$sth->finish();

		# check to see if an error has been raised and rollback if true
		if($dbh->errstr){
			$dbh->rollback;
			print "Rolling back line [$title][$link]: $dbh->errstr\n" if $DEBUG;
			return;
		}
	}
	# check to see if an error has been raised...
	# if so, rollback, if not, commit
	unless($dbh->errstr){
		print "Committing for $url\n" if $DEBUG;
		$dbh->commit;
	}else{
		print "Rolling back $url: $dbh->errstr\n" if $DEBUG;
		$dbh->rollback;
	}
	return;
}

sub clear_db {

	my ($sid) = @_;
	if( defined($sid) ){
		$dbh->do("delete from rsscontent where cid = $sid");
		unless($DBI::errstr){
			print "Successfully cleared content for $sid\n" if $DEBUG;
			return 1;
		}else{
			print "Failed to clear content for $sid: $DBI::errstr\n" if $DEBUG;
			return 0;
		}
	}
	return 0;
}