#!/usr/bin/perl 

use strict;
use warnings;

use v5.10;
use XML::LibXML 1.70;
use File::Slurp;
require LWP::UserAgent;
use Image::LibRSVG;
use SVG::Parser;
use Digest::file qw(digest_file_hex);

my $API_PATH="http://commons.wikimedia.org/w/api.php?action=query&titles=File:Tripolitanian_Front.svg&prop=imageinfo&iilimit=500&iiprop=url|timestamp&iiend=20110411220000&format=xml";

my $rsvg = new Image::LibRSVG();
my $ua = LWP::UserAgent->new;
my $response = $ua->get($API_PATH);
my (@sources, @sorted);
my %found;
if ($response->is_success) {
	my $dom = XML::LibXML->load_xml( string => $response->decoded_content );
	foreach my $node ($dom->findnodes("//ii")) {
		my $url = $node->getAttribute("url");
		my $time = $node->getAttribute("timestamp");
		my $svg = "sources/$time.svg";
		my $png = "rendered/$time.png";
		if( ! -f $svg ) {
			$response = $ua->get($url);
			if ($response->is_success) {
				my $data = $response->decoded_content;
				my $svg_dom=SVG::Parser->new()->parse($data);
				write_file($svg, $svg_dom->xmlify);
				say "wrote $svg";
			}
		}
		push @sources, [$time, digest_file_hex($svg, 'MD5')]
	}

	foreach my $source( @sources ) {
		my ($time, $md5) = @$source;
		if( exists $found{$md5} ) {
			for(reverse @sorted) {
				last if $_->[1] eq $md5;
				if( $_->[2] ) {
					say "skipping $_->[0]"
				}
				$_->[2] = 0;
			}
		} else {
			$found{$md5} = 1;
			push @sorted, [$time, $md5,1];
		}
	}
use File::Copy;
	my $counter = 0;
	system("mkdir -p res; rm -rf res/*");
	foreach my $source (reverse @sorted) {
		my ($time, $md5, $keep) = @$source;
		my $png = "rendered/$time.png";
		my $svg = "sources/$time.svg";
		my $res = sprintf "res/img_%03d.png", $counter;
		++$counter;
		unless($keep == 1) {
			# earlier "last" might have been reverted
			if( -f $png ) {
				unlink($png);
			}
			next;
		}
		if( ! -f $png ) {
			$rsvg->convertAtSize($svg, $png, 800, 329);
			say "wrote $png";
		}
		copy($png,$res);

	}
}
else {
	die $response->status_line;
}