preventing duplicate files in php - php

Question

Trying to prevent a file from being duplicated in a users directory. This is what I have come up with,
$data = $connection->getMedia($fileid);
/**
* The test begins
*/
$dir = 'media/download/'.$username;
$files1 = scandir($dir);
foreach ($files1 as $i => $file) {
if (md5($file) == md5($data)) {
//statement
echo "Duplicate entry detected.";
}
else {
file_put_contents($finalPath, $data);
}
This, however, gives me an endless loop and I cant see what it is doing. So, can anyone give me a better idea.?
EDIT: the full code:
foreach ($accounts as $username => $password) {
$connection= new Connection($username,$password);
$fileList= $connection->getFiles();
echo '<br><p>Last available files for '.$username.': <br>';
if (!file_exists('media/download/'.$username)) {
mkdir('media/download/'.$username, 0777, true);
}
for ($i=0;$i<7;$i++)
{
$fileID= $fileList[$i]->id;
$data = $connection->getMedia($fileID);
if (!strlen($data) < 1 ) {
$recipient = $fileList[$i]->recipient;
$finalPath = 'media/download/'.$username.'/to'.$recipient.'_id'.$fildID.rand(0,200).'.jpg';
file_put_contents($finalPath, $data);
echo " <img src='".$finalPath."' height='100' width='100'> ";
}
}
}