/**
 * RRULE building and parsing helpers.
 */

export type RepeatType = "Tag" | "Woche" | "Monat" | "Jahr";

const REPEAT_TYPE_TO_FREQ: Record<RepeatType, string> = {
  Tag: "DAILY",
  Woche: "WEEKLY",
  Monat: "MONTHLY",
  Jahr: "YEARLY",
};

/**
 * Build an RRULE string from repeat count and type.
 *
 * @param repeatType - The type of repetition (Tag, Woche, Monat, Jahr)
 * @param interval - The interval between repetitions (default: 1)
 * @returns RRULE string like "FREQ=WEEKLY;INTERVAL=2"
 */
export function buildRRule(repeatType: RepeatType, interval: number = 1): string {
  const freq = REPEAT_TYPE_TO_FREQ[repeatType];

  if (interval <= 1) {
    return `FREQ=${freq}`;
  }

  return `FREQ=${freq};INTERVAL=${interval}`;
}