api_get_step_details from class-ow-process-flow.php

public function api_get_step_details( $step_details_criteria ) {
	if ( ! wp_verify_nonce( $step_details_criteria->get_header( 'x_wp_nonce' ), 'wp_rest' ) ) {
		wp_die( esc_html__( 'Unauthorized access.', 'oasisworkflow' ) );
	}

	if ( ! current_user_can( 'ow_submit_to_workflow' ) && ! current_user_can( 'ow_sign_off_step' ) ) {
		wp_die( esc_html__( 'You are not allowed to get workflow step details.', 'oasisworkflow' ) );
	}

	// sanitize incoming data
	$history_id = intval( $step_details_criteria['action_history_id'] );
	$step_id    = intval( $step_details_criteria['step_id'] );
	$post_id    = intval( $step_details_criteria['post_id'] );


	// create an array of all the inputs
	$step_details_params = array(
		"step_id"    => $step_id,
		"post_id"    => $post_id,
		"history_id" => $history_id
	);

	// initialize the return array
	$step_details = array(
		"users"         => "",
		"process"       => "",
		"assign_to_all" => 0,
		"due_date"      => ""
	);

	// get step users
	$users_and_process_info = $this->get_users_in_step( $step_id, $post_id );

	if ( $users_and_process_info != null ) {
		$step_details["users"]         = $users_and_process_info["users"];
		$step_details["process"]       = $users_and_process_info["process"];
		$step_details["assign_to_all"] = $users_and_process_info["assign_to_all"];
	}

	// get the due date for the step
	$default_due_days = get_option( 'oasiswf_default_due_days' ) ? get_option( 'oasiswf_default_due_days' ) : 1;
	$due_date         = date_i18n( OASISWF_EDIT_DATE_FORMAT, current_time( 'timestamp' ) + DAY_IN_SECONDS * $default_due_days );

	$start          = '-';
	$end            = ' ';
	$replace_string = '';
	$formatted_date = preg_replace( '#(' . preg_quote( $start ) . ')(.*?)(' . preg_quote( $end ) . ')#si', '$1' . $replace_string . '$3', $due_date );
	$formatted_date = str_replace( "-", "", $formatted_date );

	$final_due_date = '';

	// Try normal parsing first
	try {
		$date_obj = new DateTime($formatted_date);
		if ($date_obj) {
			$final_due_date = $date_obj->format('Y-m-d');
		}
	} catch (Exception $e) {
		$final_due_date = '';
	}

	// If still empty, it's mean formatting failed due to invalid date Or irregular date format Or contain special characters
	// In that case, do a "digits only" parse
	if (!$final_due_date) {
		$clean_date = preg_replace('/[^\d ]/', ' ', $formatted_date);
		$clean_date = preg_replace('/\s+/', ' ', trim($clean_date));

		$parts = explode(' ', $clean_date);
		if (count($parts) >= 3) {
			list($month, $day, $year) = $parts;
			if (checkdate((int)$month, (int)$day, (int)$year)) {
				$final_due_date = sprintf('%04d-%02d-%02d', $year, $month, $day);
			}
		}
	}

	$step_details["due_date"] = $final_due_date;

	return $step_details;
}