package eu.ortlepp.notificationsender.service;

import java.util.List;

/**
 * Interface for notification senders.
 */
public interface NotificationSender {

  /**
   * Send a list of notifications.
   *
   * @param notifications The notifications to send
   * @return The result of the sending; true = successful, false = error occurred
   */
  boolean sendNotifications(final List<String> notifications);


  /**
   * Format notifications for sending (default implementation).
   * If only one notification is passed, it is returned as is.
   * If multiple notifications are passed, a numbered list of notifications is returned.
   *
   * @param notifications The notifications to format
   * @return The formatted notifications
   */
  default String formatNotifications(final List<String> notifications) {
    if (notifications.size() == 1) {
      return notifications.getFirst() + "\n\n";
    }
    StringBuilder builder = new StringBuilder();
    for (int i = 0; i < notifications.size(); i++) {
      builder.append(i + 1)
              .append(". Notification:\n")
              .append(notifications.get(i))
              .append("\n\n");
    }
    return builder.toString();
  }

}