Client - init utils methods needed for charts

fittrackee_client/src/utils/dates.ts

@@ -0,0 +1,42 @@
+import {
+  addDays,
+  addMonths,
+  addYears,
+  startOfMonth,
+  startOfWeek,
+  startOfYear,
+} from 'date-fns'
+
+export const startDate = (
+  duration: string,
+  day: Date,
+  weekStartingMonday: boolean
+): Date => {
+  switch (duration) {
+    case 'week':
+      return startOfWeek(day, { weekStartsOn: weekStartingMonday ? 1 : 0 })
+    case 'year':
+      return startOfYear(day)
+    case 'month':
+      return startOfMonth(day)
+    default:
+      throw new Error(
+        `Invalid duration, expected: "week", "month", "year", got: "${duration}"`
+      )
+  }
+}
+
+export const incrementDate = (duration: string, day: Date): Date => {
+  switch (duration) {
+    case 'week':
+      return addDays(day, 7)
+    case 'year':
+      return addYears(day, 1)
+    case 'month':
+      return addMonths(day, 1)
+    default:
+      throw new Error(
+        `Invalid duration, expected: "week", "month", "year", got: "${duration}"`
+      )
+  }
+}