Squashed 'frontend/' content from commit 63375d1

git-subtree-dir: frontend
git-subtree-split: 63375d198b2160a3a5fc4427efe888f6c37bd92f

src/app/util.ts

@@ -0,0 +1,29 @@
+import { DateFilterFn } from "@angular/material/datepicker"
+import { DateTime } from "luxon"
+
+export const weekendFilter: DateFilterFn<DateTime | null> = (
+  date: DateTime | null
+): boolean => {
+  const day = date?.weekday
+  return day !== 6 && day !== 7
+}
+
+export function filterLook(filter: DateFilterFn<DateTime | null>, ab: "ahead" | "behind" = "ahead", date: DateTime = DateTime.now(), maxSearchDays = 365): DateTime | null {
+  let currentDate = date
+  switch (ab) {
+    case "ahead":
+      for (let i = 0; i < maxSearchDays; i++) {
+        if (filter(currentDate)) return currentDate
+        currentDate = currentDate.plus({day: 1})
+      }
+      return null;
+    case "behind":
+      for (let i = 0; i < maxSearchDays; i++) {
+        if (filter(currentDate)) return currentDate
+        currentDate = currentDate.minus({day: 1})
+      }
+      return null;
+    default:
+      return null;
+  }
+}