wr: jwt 남은시간

apps/wr/src/entities/auth/lib/token-manager.ts

@@ -1,6 +1,13 @@
 import { AUTH_USER_ID, CLAIM_NAME } from "@/src/shared/config";
 import { getCookie, removeCookie, setCookie } from "@/src/shared/lib/cookie";
 
+type JwtPayload = {
+  sub?: string; // 토큰 subject
+  exp?: number; // 만료 시각(초 단위)
+  iat?: number; // 발급 시각(초 단위)
+  [key: string]: unknown;
+};
+
 export class TokenManager {
   private static instance: TokenManager;
   private refreshTimer: NodeJS.Timeout | null = null;
@@ -18,6 +25,49 @@ export class TokenManager {
     return getCookie(key);
   }
 
+  private parseJwt(token: string): JwtPayload {
+    const parts = token.split(".");
+    if (parts.length !== 3) {
+      throw new Error("유효한 JWT 형식이 아닙니다.");
+    }
+
+    const base64Url = parts[1] ?? ""; // Payload를 가져온다.
+    const base64 = base64Url.replace(/-/g, "+").replace(/_/g, "/");
+    const padded = base64.padEnd(Math.ceil(base64.length / 4) * 4, "=");
+    const jsonPayload = decodeURIComponent(
+      atob(padded)
+        .split("")
+        .map((char) => `%${char.charCodeAt(0).toString(16).padStart(2, "0")}`)
+        .join("")
+    );
+
+    return JSON.parse(jsonPayload) as JwtPayload;
+  }
+
+  public getRemainingMsFromToken(key: string = CLAIM_NAME): number | null {
+    const token = this.getToken(key);
+    if (!token) {
+      return null;
+    }
+
+    try {
+      const payload = this.parseJwt(token);
+      if (typeof payload.exp !== "number") {
+        return null;
+      }
+
+      return payload.exp * 1000 - Date.now();
+    } catch (error) {
+      console.error("JWT 파싱 오류:", error);
+      return null;
+    }
+  }
+
+  public isExpiredToken(key: string = CLAIM_NAME): boolean {
+    const remainingMs = this.getRemainingMsFromToken(key);
+    return remainingMs === null || remainingMs <= 0;
+  }
+
   public setToken(key: string, value: string): void {
     setCookie(key, value, {
       secure: window.location.protocol === "https:",