#!/usr/bin/perl -w

use strict;
use utf8;

use Encode;
use LWP::Simple;
use XML::RSS;
use Digest::MD5 qw(md5_hex);
use IO::File;
use Fcntl qw(:flock);
use Net::Twitter;
use HTTP::Lite;

#
# login for Twitter
#
our $twit = Net::Twitter->new(
	username=>'hotentry',
	password=>'xxxxxxx'
);

#
# get hotentry
#
our $cacheDir = '/path/to/.cache/rss';
mkdir $cacheDir, 0755 unless -e $cacheDir;

my $url = 'http://b.hatena.ne.jp/hotentry?mode=rss';
my $rss_cache = $cacheDir . '/' . md5_hex($url) . '.xml';
my $history_cache = $cacheDir . '/' . md5_hex($url) . '.post';

my $status = LWP::Simple::mirror($url, $rss_cache) ;
if($status == RC_NOT_MODIFIED || is_error($status)){
	die "NOT modified";
}

#
# get history
#
my @histories = ();
if(-f $history_cache){
	my $ior = IO::File->new($history_cache, 'r');
	@histories = $ior->getlines;
	$ior->close;
}


#
# parse rss
#
my $rss = XML::RSS->new();
$rss->parsefile($rss_cache);

my @rss_items = @{$rss->{items}};
my @rss_links = (); 
my %rss_hash = ();
for my $item (@rss_items){
	utf8::encode($item->{title});
	utf8::encode($item->{link});
	push(@rss_links, $item->{link});
	$rss_hash{$item->{link} . "\n"} = $item->{title};
}


#
# update twitter
#
my $iow = IO::File->new($history_cache, 'w+');
my @diff_links = &lookup(\@rss_links, \@histories);
for my $link (@diff_links){
	&update_twit($rss_hash{$link}, $link);
}

#
# update history
#
my @new_history = (@diff_links, @histories);
for my $item (@new_history){
	$iow->print($item);
}
$iow->close;



#
# update message for twitter
#
sub update_twit(){
	my($title, $link) = @_;
	my $hatena_url = &trim('http://b.hatena.ne.jp/entry/' . $link);
	my $http = new HTTP::Lite;
	my $http_res = $http->request('http://tinyurl.com/api-create.php?url=' . $hatena_url) || die('unable to get tiny url');
	my $tiny_url = $http->body();
	my $msg = $title . ' ' . $tiny_url;
	print $msg . "\n";
	$twit->update($msg);
}

#
# get diff array
#
sub lookup (\@){
	my ($target, $base) = @_;
	my %seen = (); 
	my @diff= ();
	foreach my $item (@$base) { $seen{$item} = 1; }
	foreach my $item (@$target) {
		$item = $item . "\n";
		unless ($seen{$item}) {
			push(@diff, $item);
		}
	}
	return @diff;
}

#
# trim
#
sub trim {
	my $val = shift;
	$val =~ s/^\s*(.*?)\s*$/$1/;
	return $val;
}