feat: Add date/time template options to template titles

app/utils/date.ts

@@ -0,0 +1,90 @@
+import {
+  isToday,
+  isYesterday,
+  differenceInCalendarWeeks,
+  differenceInCalendarMonths,
+  differenceInCalendarYears,
+  format as formatDate,
+} from "date-fns";
+import { startCase } from "lodash";
+import { TFunction } from "react-i18next";
+import {
+  getCurrentDateAsString,
+  getCurrentDateTimeAsString,
+  getCurrentTimeAsString,
+  unicodeCLDRtoBCP47,
+} from "@shared/utils/date";
+import User from "~/models/User";
+import { dateLocale } from "~/utils/i18n";
+
+export function dateToHeading(
+  dateTime: string,
+  t: TFunction,
+  userLocale: string | null | undefined
+) {
+  const date = Date.parse(dateTime);
+  const now = new Date();
+  const locale = dateLocale(userLocale);
+
+  if (isToday(date)) {
+    return t("Today");
+  }
+
+  if (isYesterday(date)) {
+    return t("Yesterday");
+  }
+
+  // If the current calendar week but not today or yesterday then return the day
+  // of the week as a string. We use the LocaleTime component here to gain
+  // async bundle loading of languages
+  const weekDiff = differenceInCalendarWeeks(now, date);
+
+  if (weekDiff === 0) {
+    return formatDate(Date.parse(dateTime), "iiii", {
+      locale,
+    });
+  }
+
+  if (weekDiff === 1) {
+    return t("Last week");
+  }
+
+  const monthDiff = differenceInCalendarMonths(now, date);
+
+  if (monthDiff === 0) {
+    return t("This month");
+  }
+
+  if (monthDiff === 1) {
+    return t("Last month");
+  }
+
+  const yearDiff = differenceInCalendarYears(now, date);
+
+  if (yearDiff === 0) {
+    return t("This year");
+  }
+
+  // If older than the current calendar year then just print the year e.g 2020
+  return formatDate(Date.parse(dateTime), "y", {
+    locale,
+  });
+}
+
+/**
+ * Replaces template variables in the given text with the current date and time.
+ *
+ * @param text The text to replace the variables in
+ * @param user The user to get the language/locale from
+ * @returns The text with the variables replaced
+ */
+export function replaceTitleVariables(text: string, user?: User) {
+  const locales = user?.language
+    ? unicodeCLDRtoBCP47(user.language)
+    : undefined;
+
+  return text
+    .replace("{date}", startCase(getCurrentDateAsString(locales)))
+    .replace("{time}", startCase(getCurrentTimeAsString(locales)))
+    .replace("{datetime}", startCase(getCurrentDateTimeAsString(locales)));
+}