feat(user-auth): improve token refresh logic and default values

backend/src/lib/fn/index.ts

@@ -6,4 +6,5 @@ export * from "./array";
 export * from "./dates";
 export * from "./object";
 export * from "./string";
+export * from "./time";
 export * from "./undefined";

backend/src/lib/fn/time.ts

@@ -0,0 +1,34 @@
+const convertToMilliseconds = (exp: string | number): number => {
+  if (typeof exp === "number") {
+    return exp * 1000;
+  }
+
+  const match = exp.match(/^(\d+)\s*([a-z]*)$/i);
+  if (!match) {
+    throw new Error(`Invalid expiration format: ${exp}`);
+  }
+
+  const value = parseInt(match[1], 10);
+  const unit = match[2].toLowerCase();
+
+  switch (unit) {
+    case "":
+    case "s":
+      return value * 1000; // seconds
+    case "m":
+      return value * 60 * 1000; // minutes
+    case "h":
+      return value * 60 * 60 * 1000; // hours
+    case "d":
+      return value * 24 * 60 * 60 * 1000; // days
+    default:
+      throw new Error(`Unsupported time unit: ${unit}`);
+  }
+};
+
+export const getMinExpiresIn = (exp1: string | number, exp2: string | number): string | number => {
+  const ms1 = convertToMilliseconds(exp1);
+  const ms2 = convertToMilliseconds(exp2);
+
+  return ms1 <= ms2 ? exp1 : exp2;
+};