#!/usr/bin/perl -w
#
# A perl script which chooses a random image from the internet to display in your X background. 
# The image is sourced by using a google query consisting random selection of keywords ,
# choosing a suitable page from the results and choosing an image from the page.
#
# This works well with the image stretched and with transparent terminal windows , maybe add a cronjob.
# You should need no other setup than to make the /tmp/goggle directory writeable to the current user 
# and X user.
#
# I got the idea from a script called blink by someone called dave which did the same kind of thing
# way back when altavista was a search engine worth using . so props to dave , google , London.pm ,
# all the perlmongers who monged the modules and anyone who ever wrote a silly program.
# 
#    Copyright (C) 2004 Amias channer <goggle@amias.org.uk>
#
#    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; see the file COPYING.  If not, write to
#    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
#    Boston, MA 02111-1307, USA.
#
#
# Please send feedback , patches and offers of well paid Perl programming work but no pie.
# 
##########################
# OPTIONS
##########################

# DEBUG
#my $DEBUG = 0;   # silent 
#my $DEBUG = 1;   # spew keywords only
#my $DEBUG = 2;   # spew urls
#my $DEBUG = 3;   # spew image urls
#my $DEBUG = 4;   # tell you everything that is happening

# set the default debug level when no value is supplied
my $DEBUG = 3;

# GOOGLE 
#
# your google api key , get a free one from www.google.com/apis
my $key = 'get your own !';
# the maximum amount of results to fetch , keep this high to increase your chances of a good image.
my $result_count = 30;
# prepend this to the search terms to remove certain formats with out image links 
my $crank = '-pdf -pdf -doc -ppt -words -xls -lyx -tex -txt';

# AGENT 
#
# make your goggle pretend to be another browser , you should use a known browser string or some 
# sites may refuse to serve you webpages with images )
my $agent = "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020";

# WORD LIST 
# 
# the location of a file containing a list of words to choose randomly
my $word_list ='/usr/share/dict/words';
#'/home/amias/.xchat/xchatlogs/#london.pm.xchatlog';

# the amount of random words to use
my $word_count = 2;

# IMAGE DISPLAY 
# 
# This command line will be run to set the background image and will have a filename appended in quotes.
my $command_line = "gconftool-2 -t string -s /desktop/gnome/background/picture_filename"; # GNOME
#my $command_line = "xsetroot ";

# Looping
#
# How often in seconds to loop the program or 0 not too loop at all , override with -l seconds
my $LOOP = 0;

#########################
# CODE STARTS HERE
#########################

 
if ($DEBUG == 4) { print "Loading Modules:" };

use strict;
use DBI;
use Data::Dumper;
use Data::Random::WordList;
use Net::Google::Search;
use LWP::UserAgent;
use HTML::LinkExtor;
use URI::URL;
use File::Temp qw/ tempdir tempfile /;

if ($DEBUG == 4) { print " Done \n" };

my @rand_words;

print "Before overrides : D=$DEBUG \t L=$LOOP \n"; 

# override with command line vars
foreach my $value (@ARGV) {
    if ($value =~ m/^\-d/) { $DEBUG = substr($value,2) };
    if ($value =~ m/^\-l/) { $LOOP = substr($value,2) };
    if ($value !~ m/^\-/ ) { unshift @rand_words , $value };
}

print "After overrides : D=$DEBUG \t L=$LOOP \t ".join(',',@rand_words)."\n";
my (@imgs,@uniq_images);
my $filename;
my ($wl,$search,$ua);
my $quit = 'no';

while ($quit eq 'no') {
    # get random words if needed
    if ( $#rand_words < 0 ){
	$wl = new Data::Random::WordList( wordlist => $word_list );
	@rand_words = $wl->get_words($word_count);
	$wl->close();
    }
    
    print "Using ".join(' , ',@rand_words)."\n" if ($DEBUG > 0);
    
# apply hacks to force html pages
    unshift @rand_words,$crank;
    
    if ($DEBUG == 4) { print "Querying Google:" };
# look them up via google
    $search = Net::Google::Search->new( { key => $key, max_results => $result_count,}
			       ) or die('error creating search object');
    $search->query(@rand_words);
    if ($DEBUG == 4) { print "Done \n" };

    if ($DEBUG == 4) { print "Loading LWP:" };
    
# create LWP agent
    $ua = LWP::UserAgent->new;
    $ua->agent($agent);
    
    if ($DEBUG == 4) { print "Done \n" };
    
# loop through the results
foreach my $result (@{$search->results()}) {
    
    # get the url for the current result
    my $url = $result->URL() || 'null';
    
    # allow only a few known html docs  or /
    if ( $url =~ m/(html|htm|asp|pl|cgi)/ || $url =~ m/\/$/ ) {
	
	print "Got URL: $url \n" if ($DEBUG > 1);
	
	# declare storage for images and callback routine
	sub callback {
	    my($tag, %attr) = @_;
	    return if $tag ne 'img';  # we only look closer at <img ...>
	    push(@imgs, values %attr);
	}
	
	if ($DEBUG == 4) { print "Parsing Url:$url" };
	# Make the parser.
	my $p = HTML::LinkExtor->new(\&callback);
	
	# Request document and parse it as it arrives
	my $res = $ua->request(HTTP::Request->new(GET => $url), sub {$p->parse($_[0])} );
	
	# get url base
	my $base = $res->base;
	
	if ($DEBUG == 4) { print "Done \n" };
	print "Got images $#imgs:\n" if ($DEBUG >2);
	# list , dedupe and expand urls images
	my %seen;
	foreach my $image (@imgs) {
	    $seen{$image}++;
	    print "scanning \t $image (".$seen{$image}.") " if ($DEBUG >2);
	    unless ($seen{$image} > 2 ||
		    $image =~ m/(
				 spacer|clear|icon|arrow|banner|pixel|symbol|1x1|htm|
				 mast|\?|brand|trans|logo|nav|shim|menu|line|top|
				 bottom|button|\#|dot|zip|xml|w3c|adgo
				 )/ix ) {
		push(@uniq_images, url($image,$base)->abs);
		print "\t passed" if ($DEBUG >2);
	    }
	    print "\n" if ($DEBUG >2);
	}
	if ($#imgs ne -1) { last; };
    } else {
	print "$url doesn't look like HTML - skipping\n" if ($DEBUG >1);
    }
}
    
# randomize the order of the image array
    for (my $i = @uniq_images; --$i;) {
	my $j = int rand ($i+1);
	next if ($i == $j || $i < 0);
	my $temp = $uniq_images[$i];
	$uniq_images[$i] = $uniq_images[$j];
	$uniq_images[$j] = $temp;
    }
    
    my $image_file;
    
# try downloading an image , if not do the next
    foreach my $image (@uniq_images) {
	print "using $image \n" if ($DEBUG > 1);
	# download image to temp location
	my $getimage = $ua->request(HTTP::Request->new(GET => $image));
	if ($getimage->content) {
	    my ($fh,$filename) = tempfile( DIR=>'/tmp/goggle');  # make the tempfile configurable
	    print $fh $getimage->content or (next);
	    close $fh or (next);	    
	    print "wrote to ".$filename."\n" if ($DEBUG > 0);
	    $image_file = $filename;
	    last;
	}
    }
    
# now load image on to x background
    system "$command_line \"$image_file\"";
    
    if ($LOOP > 0) {
	print "sleeping for $LOOP \n";
	# null the random words in preperation for next loop
	$#rand_words = 0;

	# undef the google object to keep it fresh
	$search = undef;
	sleep ($LOOP);
    } else {
	$quit= 'yes';
    }
}