Upload multiple files

if (!empty($_FILES)) {

            // Set filename and upload path
            $tempFile = $_FILES['file']['tmp_name'];
            $fileName = $_FILES['file']['name'];
            $fileSize = $_FILES['file']['size'];
            $targetPath = getcwd() . '/uploads/';
            $targetFile = $targetPath . $fileName;
            $initialFileName = $fileName;

            // Get file info to get file name
            $path_parts = pathinfo($targetFile);

            // Duplicate file counter
            $fileIncrement = 1;

            // Prevent rewriting of existing documents with the same name
            while (file_exists($targetFile) && $fileIncrement < 50) {    // Limit to 50 duplicate files for safety.
                // 1 increment will likely be enough

                // If file with the name exists add '-file-1' continue increment by replacing last increment
                $pattern = '/(.+)-attachment-(\d)+/i';
                $replacement = '${1}';
                $originalFilename = preg_replace($pattern, $replacement, $path_parts['filename']);

                // Prepare new filename and file path
                $fileName = $originalFilename . '-attachment-' . $fileIncrement . '.' . $path_parts['extension'];
                $targetFile = $targetPath . $fileName;

                // Prepare next increment
                $fileIncrement += 1;

            }

            // Moves temporary file to new location
            move_uploaded_file($tempFile, $targetFile);

            if ($file_id = $this->attachments_model->add_attachment(array('filename' => $fileName, 'original_filename'=>$initialFileName, 'file_size' => $fileSize))) {
                return $this->output
                    ->set_content_type('application/json')
                    ->set_status_header(200)
                    ->set_output(json_encode(array('filepath' => $targetFile, 'file_id' => $file_id, 'file_name'=>$fileName)));
            }

        }else{
            //
            return $this->output
                ->set_content_type('application/json')
                ->set_status_header(200)
                ->set_output(json_encode(array('success' => false)));
        }