bp_document_upload_handler( string $file_id = 'file' )

function bp_document_upload_handler( $file_id = 'file' ) {

	/**
	 * Include required files.
	 */

	if ( ! function_exists( 'wp_generate_attachment_metadata' ) ) {
		require_once ABSPATH . 'wp-admin' . '/includes/image.php';
		require_once ABSPATH . 'wp-admin' . '/includes/file.php';
		require_once ABSPATH . 'wp-admin' . '/includes/media.php';
	}

	if ( ! function_exists( 'media_handle_upload' ) ) {
		require_once ABSPATH . 'wp-admin/includes/admin.php';
	}

	add_filter( 'upload_mimes', 'bp_document_allowed_mimes', 9999999, 1 );

	$aid = media_handle_upload(
		$file_id,
		0,
		array(),
		array(
			'test_form'            => false,
			'upload_error_strings' => array(
				false,
				__( 'The uploaded file exceeds ', 'buddyboss' ) . bp_document_file_upload_max_size( true ),
				__( 'The uploaded file exceeds ', 'buddyboss' ) . bp_document_file_upload_max_size( true ),
				__( 'The uploaded file was only partially uploaded.', 'buddyboss' ),
				__( 'No file was uploaded.', 'buddyboss' ),
				'',
				__( 'Missing a temporary folder.', 'buddyboss' ),
				__( 'Failed to write file to disk.', 'buddyboss' ),
				__( 'File upload stopped by extension.', 'buddyboss' ),
			),
		)
	);

	// if has wp error then throw it.
	if ( is_wp_error( $aid ) ) {
		return $aid;
	}

	$attachment = get_post( $aid );

	if ( ! empty( $attachment ) ) {
		update_post_meta( $attachment->ID, 'bp_document_upload', true );
		update_post_meta( $attachment->ID, 'bp_document_saved', '0' );

		return $attachment;
	}

	return new WP_Error( 'error_uploading', __( 'Error while uploading document.', 'buddyboss' ), array( 'status' => 500 ) );

}