refactor: organize backend by business responsibility

src/modules/investments/investment-calendar.ts

@@ -0,0 +1,43 @@
+export type DateOnlyRange = { from: string; to: string };
+const moscow = 'Europe/Moscow';
+export function moscowDate(value: Date): string {
+  const parts = new Intl.DateTimeFormat('en-CA', {
+    timeZone: moscow,
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+  }).formatToParts(value);
+  const get = (type: string) => parts.find((part) => part.type === type)?.value;
+  return `${get('year')}-${get('month')}-${get('day')}`;
+}
+
+export function dateOnlyBounds(range: DateOnlyRange): { from: Date; to: Date } {
+  const from = dateParts(range.from);
+  const end = dateParts(range.to);
+  const to = new Date(Date.UTC(end[0], end[1] - 1, end[2], 20, 59, 59, 999));
+  return {
+    from: new Date(Date.UTC(from[0], from[1] - 1, from[2], -3)),
+    to: to > new Date() ? new Date() : to,
+  };
+}
+
+export function dateParts(value: string): [number, number, number] {
+  const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value);
+  if (!match) throw new Error('Invalid date');
+  const parts = [Number(match[1]), Number(match[2]), Number(match[3])] as [
+    number,
+    number,
+    number,
+  ];
+  if (utcDate(value).toISOString().slice(0, 10) !== value)
+    throw new Error('Invalid date');
+  return parts;
+}
+
+export function utcDate(value: string): Date {
+  const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value);
+  if (!match) return new Date(NaN);
+  return new Date(
+    Date.UTC(Number(match[1]), Number(match[2]) - 1, Number(match[3])),
+  );
+}