Added sorting functions in search

src/models/Date.ts

@@ -7,3 +7,42 @@ export interface LeimDate {
 
 export type LeimPeriod = 'ante' | 'nante'
 export type LeimPeriodShort = 'A.R' | 'N.R'
+export type LeimDateOrder = 'asc' | 'desc'
+
+/**
+ * Check whether two dates are identical
+ *
+ * @param date1 First date
+ * @param date2 Second date
+ * @returns True if the dates are identical
+ */
+export function areDatesIdentical(date1: LeimDate, date2: LeimDate) {
+  // To refacto to be more precise
+  return JSON.stringify({ ...date1 }) === JSON.stringify({ ...date2 })
+}
+
+/**
+ * Compare dates
+ *
+ * @param date1 First date
+ * @param date2 Second date
+ * @returns 1 means the first date comes before the second, -1 means the second comes before the first, and 0 if they're identical
+ */
+export function compareDates(a: LeimDate, b: LeimDate, order: LeimDateOrder = 'desc'): number {
+  // Reverses the order if specified
+  const orderFactor = order === 'desc' ? 1 : -1
+
+  if (a.period === 'ante' && b.period === 'nante') return -1 * orderFactor
+  if (a.period === 'nante' && b.period === 'ante') return 1 * orderFactor
+
+  if (a.year < b.year) return -1 * orderFactor
+  if (a.year > b.year) return 1 * orderFactor
+
+  if (a.month < b.month) return -1 * orderFactor
+  if (a.month > b.month) return 1 * orderFactor
+
+  if (a.day < b.day) return -1 * orderFactor
+  if (a.day > b.day) return 1 * orderFactor
+
+  return 0
+}