Initial Commit

packages/security-stack/security/license/src/time/time.ts

@@ -0,0 +1,60 @@
+import type { Clock } from "@suaveplan/types";
+import { MS_PER_DAY } from "../constants/constants.js";
+import { TimeEncodingType } from "../types/license.js";
+
+const defaultClock: Clock = () => Date.now();
+
+/**
+ * Convert a `Date` (or now) to days since the Unix epoch. The 18-bit
+ * `timeValue` field can hold ~718 years of day numbers.
+ */
+export function getDayNumber(date?: Date, clock: Clock = defaultClock): number {
+    const ms = date !== undefined ? date.getTime() : clock();
+    return Math.floor(ms / MS_PER_DAY);
+}
+
+/** Inverse of {@link getDayNumber}. */
+export function dayNumberToDate(dayNumber: number): Date {
+    return new Date(dayNumber * MS_PER_DAY);
+}
+
+/**
+ * Determine whether a license is expired given its time-encoding metadata.
+ * The optional `clock` defaults to `Date.now()` and is read only when
+ * `referenceDate` is omitted.
+ */
+export function checkExpiration(
+    timeEncodingType: TimeEncodingType,
+    timeValue: number,
+    referenceDate?: Date,
+    creationDate?: Date,
+    clock: Clock = defaultClock
+): { isExpired: boolean; expirationDate?: Date } {
+    const ref = referenceDate ?? new Date(clock());
+
+    switch (timeEncodingType) {
+        case TimeEncodingType.NONE:
+            return { isExpired: false };
+
+        case TimeEncodingType.ABSOLUTE_DAYS: {
+            const expirationDate = dayNumberToDate(timeValue);
+            return { isExpired: ref > expirationDate, expirationDate };
+        }
+
+        case TimeEncodingType.RELATIVE_DAYS: {
+            const creation = creationDate ?? ref;
+            const expirationDate = new Date(
+                creation.getTime() + timeValue * MS_PER_DAY
+            );
+            return { isExpired: ref > expirationDate, expirationDate };
+        }
+
+        case TimeEncodingType.ABSOLUTE_TIMESTAMP: {
+            const expirationDate = new Date(timeValue * 1000);
+            return { isExpired: ref > expirationDate, expirationDate };
+        }
+
+        default:
+            return { isExpired: false };
+    }
+}