Uploads a file [PHP]

upload_file.php

<?php
/**
 * Uploads a file
 * 
 * @param $_FILES $file
 * @param string $directory
 * @param string $filename
 * @param array $formats
 * @return string/array filepath/errors
*/
function upload_file( $file, $directory = '/uploads', $name = NULL, $formats = NULL )
{
	$fullpath = $_SERVER['DOCUMENT_ROOT'].$directory;
	$errors = array();

	// Make directory if doesn't exist
	if ( !is_dir($fullpath ) ) {
		if ( !mkdir( $fullpath, 0700 ) ) {
			array_push( $errors, 'There was a problem uploading to the given directory.' );
		}
	}

	// Check if filetype is allowed (document)
	$type = pathinfo( $file['name'], PATHINFO_EXTENSION );
	$allowed = $formats != NULL ? in_array( strtolower( $type ), $formats ) : true;
	if ( $allowed ) {

		// Set name
		$name = $name == NULL ? 'upload-' . date('Y-m-d-g-i-s') . '.' . $type : $name . '.' . $type;

		// Move uploaded file to the directory
		if ( move_uploaded_file( $file['tmp_name'], $fullpath . '/' . $name ) ) {
			return $directory . $name;

		// Problem with moving file
		} else {
			array_push( $errors, 'There was a problem processing your file.' );
		}

	// Invalid filetype
	} elseif ( $formats != NULL ) {
		array_push( $errors, 'Your file must be one of the following types: '.implode( ', ', $formats ) );
	}

	return $errors;
}