<?php

## fetch a chart either from cache or remotely
## used for google charts, so verify that's the one being used

$url = $_GET['url'];
$url = str_replace('&amp;','&',$url);

if (strpos($url,'chart.apis.google.com/chart') === false) {
  print 'Error';
  exit;
}

## cleanup once a month
Sql_Query(sprintf('delete from %s where month(added) < month(now())',$GLOBALS['tables']['gchartcache']));

$cache = Sql_Fetch_Row_Query(sprintf('select content from %s where url = "%s"',$GLOBALS['tables']['gchartcache'],$url),1);

ob_end_clean();
ob_start();

if (empty($cache[0])) {
  $content = file_get_contents($url);
  Sql_Query(sprintf('insert into %s (url,content,added) values("%s","%s",now())',$GLOBALS['tables']['gchartcache'],$url,base64_encode($content)),1);
} else {
  $content = base64_decode($cache[0]);
}
header('Content-type: image/png');
print $content;

exit;