fix: handle cache tags for service tokens

server/tokenManager.ts

@@ -1,35 +1,58 @@
+import { revalidateTag, unstable_cache } from "next/cache"
+
 import { env } from "@/env/server"
 
+import { generateServiceTokenTag } from "@/utils/generateTag"
+
+import { ServiceTokenScope } from "@/types/enums/serviceToken"
 import { ServiceTokenResponse } from "@/types/tokens"
 
-const SERVICE_TOKEN_REVALIDATE_SECONDS = 3599 // 59 minutes and 59 seconds.
+async function getServiceToken(scopes: ServiceTokenScope[]) {
+  const response = await fetch(`${env.CURITY_ISSUER_USER}/oauth/v2/token`, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/x-www-form-urlencoded",
+      Accept: "application/json",
+    },
+    body: new URLSearchParams({
+      grant_type: "client_credentials",
+      client_id: env.CURITY_CLIENT_ID_SERVICE,
+      client_secret: env.CURITY_CLIENT_SECRET_SERVICE,
+      scope: scopes.join(" "),
+    }),
+  })
+
+  if (!response.ok) {
+    throw new Error("Failed to obtain service token")
+  }
+
+  return response.json()
+}
 
 export async function fetchServiceToken(
-  scopes: string[]
+  scopes: ServiceTokenScope[]
 ): Promise<ServiceTokenResponse> {
   try {
-    const response = await fetch(`${env.CURITY_ISSUER_USER}/oauth/v2/token`, {
-      method: "POST",
-      headers: {
-        "Content-Type": "application/x-www-form-urlencoded",
-        Accept: "application/json",
-      },
-      body: new URLSearchParams({
-        grant_type: "client_credentials",
-        client_id: env.CURITY_CLIENT_ID_SERVICE,
-        client_secret: env.CURITY_CLIENT_SECRET_SERVICE,
-        scope: scopes.join(" "),
-      }),
-      next: {
-        revalidate: SERVICE_TOKEN_REVALIDATE_SECONDS,
-      },
-    })
+    const tag = generateServiceTokenTag(scopes)
+    const getCachedJwt = unstable_cache(
+      async (scopes) => {
+        const jwt = await getServiceToken(scopes)
 
-    if (!response.ok) {
-      throw new Error("Failed to obtain service token")
+        const expiresAt = Date.now() + jwt.expires_in * 1000
+        return { expiresAt, jwt }
+      },
+      scopes,
+      { tags: [tag] }
+    )
+
+    const cachedJwt = await getCachedJwt(scopes)
+    if (cachedJwt.expiresAt < Date.now()) {
+      revalidateTag(tag)
+      const newToken = await getServiceToken(scopes)
+      return newToken
     }
 
-    return response.json()
+    return cachedJwt.jwt
   } catch (error) {
     console.error("Error fetching service token:", error)
     throw error

server/trpc.ts

@@ -17,6 +17,10 @@ import { langInput } from "./utils"
 
 import type { Session } from "next-auth"
 
+import {
+  ServiceTokenScope,
+  ServiceTokenScopeEnum,
+} from "@/types/enums/serviceToken"
 import type { Meta } from "@/types/trpc/meta"
 
 const t = initTRPC
@@ -121,7 +125,7 @@ export const safeProtectedProcedure = t.procedure.use(async function (opts) {
   })
 })
 
-function createServiceProcedure(serviceName: string) {
+function createServiceProcedure(serviceName: ServiceTokenScope) {
   return t.procedure.use(async (opts) => {
     const { access_token } = await fetchServiceToken([serviceName])
     if (!access_token) {
@@ -135,9 +139,15 @@ function createServiceProcedure(serviceName: string) {
   })
 }
 
-export const bookingServiceProcedure = createServiceProcedure("booking")
-export const hotelServiceProcedure = createServiceProcedure("hotel")
-export const profileServiceProcedure = createServiceProcedure("profile")
+export const bookingServiceProcedure = createServiceProcedure(
+  ServiceTokenScopeEnum.booking
+)
+export const hotelServiceProcedure = createServiceProcedure(
+  ServiceTokenScopeEnum.hotel
+)
+export const profileServiceProcedure = createServiceProcedure(
+  ServiceTokenScopeEnum.profile
+)
 
 export const serverActionProcedure = t.procedure.experimental_caller(
   experimental_nextAppDirCaller({

types/enums/serviceToken.ts

@@ -0,0 +1,7 @@
+export enum ServiceTokenScopeEnum {
+  profile = "profile",
+  hotel = "hotel",
+  booking = "booking",
+}
+
+export type ServiceTokenScope = keyof typeof ServiceTokenScopeEnum

utils/generateTag.ts

@@ -99,3 +99,13 @@ export function generateLoyaltyConfigTag(
 ) {
   return `${lang}:loyalty_config:${contentTypeUid}:${id}`
 }
+
+/**
+ * Function to generate tags for service tokens
+ *
+ * @param serviceTokenScope scope of service token
+ * @returns string
+ */
+export function generateServiceTokenTag(serviceTokenScopes: string[]) {
+  return `service_token:${serviceTokenScopes.join("-")}`
+}