add shared resources directory

shared/timezone.ts

@@ -0,0 +1,217 @@
+export const AUTO_TZ = "auto";
+export const DEFAULT_TZ = "UTC";
+
+export function resolveTz(tz?: string | null): string {
+  if (tz && tz !== AUTO_TZ) return tz;
+  try {
+    return Intl.DateTimeFormat().resolvedOptions().timeZone || DEFAULT_TZ;
+  } catch {
+    return DEFAULT_TZ;
+  }
+}
+
+export function dateStrInTz(date: Date, tz: string): string {
+  const parts = new Intl.DateTimeFormat("en-US", {
+    timeZone: tz,
+    year: "numeric",
+    month: "2-digit",
+    day: "2-digit",
+  }).formatToParts(date);
+  const get = (type: string) =>
+    parts.find((p) => p.type === type)?.value ?? "00";
+  return `${get("year")}-${get("month")}-${get("day")}`;
+}
+
+export function weekdayInTz(date: Date, tz: string): number {
+  const parts = new Intl.DateTimeFormat("en-US", {
+    timeZone: tz,
+    weekday: "short",
+  }).formatToParts(date);
+  const wd = parts.find((p) => p.type === "weekday")?.value ?? "";
+  const map: Record<string, number> = {
+    Sun: 0,
+    Mon: 1,
+    Tue: 2,
+    Wed: 3,
+    Thu: 4,
+    Fri: 5,
+    Sat: 6,
+  };
+  return map[wd] ?? date.getDay();
+}
+
+export function todayInTz(tz: string): string {
+  return dateStrInTz(new Date(), tz);
+}
+
+export function addDaysStr(dateStr: string, days: number): string {
+  const [y, m, d] = dateStr.split("-").map(Number);
+  const dt = new Date(Date.UTC(y, m - 1, d + days));
+  return dt.toISOString().slice(0, 10);
+}
+
+export function weekStart(payday: number, tz: string): string {
+  const today = todayInTz(tz);
+  const wd = weekdayInTz(new Date(), tz);
+  const back = (((wd - payday) % 7) + 7) % 7;
+  return addDaysStr(today, -back);
+}
+
+// The first configured-payday day strictly after dateStr (used to gate
+// payday-settled bonus rewards). Weekly: periodEnd (weekStart+6) → next payday.
+export function nextPaydayAfter(
+  dateStr: string,
+  payday: number,
+  tz: string,
+): string {
+  let d = addDaysStr(dateStr, 1);
+  while (weekdayInTz(new Date(d + "T12:00:00Z"), tz) !== payday) {
+    d = addDaysStr(d, 1);
+  }
+  return d;
+}
+
+function monthStartStr(): string {
+  const d = new Date();
+  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}-01`;
+}
+
+function monthEndStr(month?: string): string {
+  if (!month) {
+    const d = new Date();
+    month = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}`;
+  }
+  const [y, m] = month.split("-").map(Number);
+  const lastDay = new Date(y, m, 0).getDate();
+  return `${month}-${String(lastDay).padStart(2, "0")}`;
+}
+
+export function periodStart(
+  period: string,
+  payday: number,
+  tz: string,
+): string {
+  if (period === "daily") return todayInTz(tz);
+  if (period === "weekly") return weekStart(payday, tz);
+  if (period === "monthly") return monthStartStr();
+  return weekStart(payday, tz);
+}
+
+export function periodEnd(period: string, start: string): string {
+  if (period === "daily") return start;
+  if (period === "weekly") return addDaysStr(start, 6);
+  if (period === "monthly") return monthEndStr(start.slice(0, 7));
+  return start;
+}
+
+// The completion window a chore of a given frequency is "done for" in the
+// current period. Weekly chores are done once per week ([weekStart, +7)),
+// daily chores once per day ([today, +1)). Half-open [from, to).
+export function periodWindow(
+  frequency: string,
+  payday: number,
+  tz: string,
+): { from: string; to: string } {
+  if (frequency === "weekly") {
+    const from = weekStart(payday, tz);
+    return { from, to: addDaysStr(from, 7) };
+  }
+  const from = todayInTz(tz);
+  return { from, to: addDaysStr(from, 1) };
+}
+
+// True if any completion date falls within the current period window for the
+// chore's frequency. Dates may be YYYY-MM-DD or ISO (time portion ignored).
+export function isCompleteForPeriod(
+  frequency: string,
+  payday: number,
+  tz: string,
+  dates: string[],
+): boolean {
+  const { from, to } = periodWindow(frequency, payday, tz);
+  return dates.some((d) => {
+    const day = (d || "").slice(0, 10);
+    return day >= from && day < to;
+  });
+}
+
+export function wallClockToUtc(
+  dateStr: string,
+  time: string,
+  tz: string,
+): number {
+  const [y, m, d] = dateStr.split("-").map(Number);
+  const [h, min] = time.split(":").map(Number);
+  let epoch = Date.UTC(y, m - 1, d, h, min);
+  for (let i = 0; i < 4; i++) {
+    const parts = new Intl.DateTimeFormat("en-US", {
+      timeZone: tz,
+      year: "numeric",
+      month: "2-digit",
+      day: "2-digit",
+      hour: "2-digit",
+      minute: "2-digit",
+      hour12: false,
+    }).formatToParts(new Date(epoch));
+    const get = (type: string) =>
+      parts.find((p) => p.type === type)?.value ?? "00";
+    const gotDate = `${get("year")}-${get("month")}-${get("day")}`;
+    let gotHour = parseInt(get("hour"), 10);
+    if (gotHour === 24) gotHour = 0;
+    const gotEpoch = Date.UTC(
+      parseInt(get("year"), 10),
+      parseInt(get("month"), 10) - 1,
+      parseInt(get("day"), 10),
+      gotHour,
+      parseInt(get("minute"), 10),
+    );
+    if (gotEpoch === epoch && gotDate === dateStr) break;
+    epoch = Date.UTC(y, m - 1, d, h, min) + (epoch - gotEpoch);
+  }
+  return epoch;
+}
+
+export const COMMON_TIMEZONES: string[] = [
+  "Europe/London",
+  "Europe/Paris",
+  "Europe/Berlin",
+  "Europe/Madrid",
+  "Europe/Rome",
+  "Europe/Amsterdam",
+  "Europe/Lisbon",
+  "Europe/Dublin",
+  "Europe/Warsaw",
+  "Europe/Stockholm",
+  "Europe/Athens",
+  "Europe/Istanbul",
+  "Europe/Moscow",
+  "America/New_York",
+  "America/Chicago",
+  "America/Denver",
+  "America/Los_Angeles",
+  "America/Toronto",
+  "America/Vancouver",
+  "America/Sao_Paulo",
+  "America/Mexico_City",
+  "Asia/Tokyo",
+  "Asia/Shanghai",
+  "Asia/Hong_Kong",
+  "Asia/Singapore",
+  "Asia/Seoul",
+  "Asia/Kolkata",
+  "Asia/Dubai",
+  "Asia/Jerusalem",
+  "Asia/Bangkok",
+  "Asia/Manila",
+  "Australia/Sydney",
+  "Australia/Melbourne",
+  "Australia/Brisbane",
+  "Australia/Perth",
+  "Australia/Adelaide",
+  "Pacific/Auckland",
+  "Africa/Johannesburg",
+  "Africa/Cairo",
+  "Africa/Lagos",
+  "Africa/Nairobi",
+  "UTC",
+];