<?php

// You will need SimplePie
include_once("simplepie.inc");

define("THE_FILE", strval(date("YtdHms") . rand(0,9)) . ".jpg");
define("THE_TEMP", "temp_" . THE_FILE . ".jpg");
define("MAX_W", 1024);
define("MAX_H", 768);
define("AREA", MAX_H * MAX_W);

// Error messages
function PikachoorError($msg = null) {
    if ($msg == null) {
        PikachoorError('No error message passed.');
    }
    echo('ERROR: ' . $msg);
    exit;
}

function getImage(&$baseimg, &$area, $url = null) {
    $tempimg = null;
    $imgdata = getimagesize($url);
    
    if (preg_match("/jpeg/", $imgdata['mime'])) {
        $tempimg = @imagecreatefromjpeg($url);
    }
    else if (preg_match("/png/", $imgdata['mime'])) {
        $tempimg = @imagecreatefrompng($url);
    }
    else if (preg_match("/gif/", $imgdata['mime'])) {
        $tempimg = @imagecreatefromgif($url);
    }
    else {
        PikachoorError("Unknown file type...");
    }

    if ($tempimg != false) {
        imagejpeg($tempimg, THE_TEMP);
        imagedestroy($tempimg);
        
        $imgdata = getimagesize(THE_TEMP);
        $newimg = imagecreatefromjpeg(THE_TEMP);
        $coord = findFirstBlank($area);
        $coord['w'] = $imgdata[0];
        $coord['h'] = $imgdata[1];
        
        imagecopy($baseimg, $newimg, $coord['x'], $coord['y'], 0, 0, $imgdata[0], $imgdata[1]);
        imagejpeg($baseimg, THE_FILE);
        imagedestroy($newimg);
        unlink(THE_TEMP);
        return $coord;
    }
    else {
        sleep(1);
        getImage($url);
    }
}

function fetchImageList($urls=null) {
    $list = array();
    $feed = new SimplePie();
    $feed->enable_cache(false);
    $feed->enable_order_by_date();
    $feed->set_feed_url($urls);
    $feed->init();
    $feed->handle_content_type();
    
    foreach($feed->get_items() as $i) {
        $html = $i->get_description();
        if (strlen($html) == 0) {
            $html = $i->get_content();
        }
        preg_match('/src="(.*)"(.*)>/', $html, $matches);
        $parts = preg_split('/\"/', $matches[1]);
        $list[] = $parts[0];
    }
    if (count($list) == 0) {
        return false;
    }
    return $list;
}

function initializeArray(&$area) {
    for($y = 0; $y < MAX_H; $y++) {
        for($x = 0; $x < MAX_W; $x++) {
            $area[$y][$x] = "0";
        }
    }
}

function fillinArray(&$area, $img=null) {
    $yend = 0;
    $xend = 0;
    
    $lasty = $img['y'] + $img['h'];
    if ($lasty >= MAX_H) { $yend = MAX_H; }
    else { $yend = $lasty; }
    
    $lastx = $img['x'] + $img['w'];
    if ($lastx >= MAX_W) { $xend = MAX_W; }
    else { $xend = $lastx; }
    
    for($y = $img['y']; $y < $yend; $y++) {
        for($x = $img['x']; $x < $xend; $x++) {
            $area[$y][$x] = "1";
        }
    }    
}

function totalArray(&$area) {
    $total = 0;
    for($y = 0; $y < MAX_H; $y++) {
        for($x = 0; $x < MAX_W; $x++) {
            $total += $area[$y][$x];
        }
    }
    return $total;
}

function findFirstBlank(&$area) {
    $coords = array('x' => 0, 'y' => 0);
    for($y = 0; $y < MAX_H; $y++) {
        for($x = 0; $x < MAX_W; $x++) {
            if ($area[$y][$x] == "0") {
                $coords['y'] = $y; $coords['x'] = $x;
                return $coords;
            }
        }
    }
}

function noDuplicateUrl(&$pics, &$used) {
    $count_check = 0;
    $url = $pics[rand(0, count($pics)-1)];
    while (in_array($url, $used)) {
        $url = $pics[rand(0, count($pics)-1)];
        $count_check++;
        if ($count_check > 100) { break; }
    }
    $used[] = $url;
    return $url;
}

function main($urls=null) {
    if ($urls == null || count($urls) == 0) { PikachoorError("No urls given."); }
    $pics = fetchImageList($urls);
    if ($pics == false) { PikachoorError("No urls."); }
    
    $total = 0; $used = array(); $area = array();
    
    initializeArray($area);
    
    $baseimg = imagecreatetruecolor(MAX_W, MAX_H);
    $bg = imagecolorallocate($baseimg, 0xFF, 0xFF, 0xFF);
    imagefill($baseimg, 0, 0, $bg);
    
    while ($total < AREA) {
        $img = getImage($baseimg, $area, noDuplicateUrl($pics, $used));
        fillinArray($area, $img);
        $total = totalArray($area);
    }
    
    imagedestroy($baseimg);
    printf("Your collage is: %s\n", THE_FILE);    
}

// Starts the program
main(array("http://backend.deviantart.com/rss.xml?q=boost%3Apopular+pinkie%20pie&type=deviation",
           "http://feed.photobucket.com/images/pinkie+pie/feed.rss"));

?>