<?
/**
  * gravcache - a MySQL- and PHP caching system for Gravatar
  * Copyright (C) 2004 Tom Adams
  * Ported to PHP by Colin Ogilvie
  *
  * 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; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  * This is a Gravatar cache as proposed by Neil Turner
  * Gravatar:
  * http://www.gravatar.com/
  * Neil Turner's proposal:
  * http://www.neilturner.me.uk/2005/Jan/02/caching_gravatars.html
  *
  */

$mysql_server = "localhost";
$mysql_database = "grav";
$mysql_table = "grav_cache";
$mysql_user = "username";
$mysql_pass = "password";

// URL to fetch the Gravatar from
$gravuri = "http://www.gravatar.com/avatar.php";

// Malformed Request
if (!array_key_exists('gravatar_id', $_GET))
{
    doError();
}

// URL Paramaters
$gravatar_id = $_GET['gravatar_id'];
$rating = $_GET['rating'];
$size = $_GET['size'];
$default = $_GET['default'];
$border = $_GET['border'];

// Check table for existing avatar that is up-to-date

$dbh = @mysql_connect($mysql_server, $mysql_user, $mysql_pass) or doError("Database Connection Failed");
@mysql_select_db($mysql_database, $dbh) or doError("Database Select Failed");
$res = @mysql_query('SELECT data FROM `'.$mysql_table."` WHERE md5=MD5('".$gravatar_id."') AND DATE_SUB(CURDATE(),INTERVAL 1 DAY) <= updated;") or doError("Query Failed");

// Get Image
if ($data = @mysql_fetch_row($res))
{
    // Image came from the datbase
    $image = $data[0];
}
else
{
    // Construct Gravatar URL
    $url = $gravuri . create_link(array("gravatar_id" => $gravatar_id, "rating" => $rating, "size" => $size, "default" => $default, "border" => $border));
    // XXX:
    // Could create this request manually, to enable sniffing of the HTTP Response code
    $handle = fopen($url, "r");
    // The result of the URL Request, no headers
    $rawimage = "";
    do
    {
        $data = fread($handle, 8192);
        if (strlen($data) == 0) { break; }
        $rawimage .= $data;
    } while (true);
    fclose($handle);
    // Base 64 encode the image, for storing in the database
    // Note: It should be possible to store the actual raw image in a "BLOB" field
    // but the original script didn't do this.
    $image = base64_encode($rawimage);
    $res = @mysql_query('REPLACE INTO `'.$mysql_table."` SET md5=MD5('".$gravatar_id."'), updated=NOW(), data='".$image."';") or doError("Query Failed");
}

// I have no idea how to determine the mime type
// But this seems to work for PNG/GIF/JPEG... for some reason
// (Firefox 1.0)

// XXX: 
// I can only think of constructing the HTTP request above manually.
// This would mean I could sniff and store the Content-Type header from the HTTP
// Response and store it in the database.

header("Content-Type: image/jpeg");
print base64_decode($image);


// Error Handler
function doError($msg = "Bad Request")
{
    header("Content-Type: text/plain");
    print $msg;
    exit;
}

// Helper Function
function create_link ($in) {
	$out = "?";
	$i = 1;
	foreach ($in as $field => $val)
    {
	   if ($field && $val)
	   {
            if ($i) { $out .= "&"; }
            $out .= $field . "=" . urlencode($val);
	      	$i++;
	   }
    }
	return $out;
}