Returns the oauth access token "expires at" date

- in case the server did return it

Fixes: SE-13502

src/main/java/sirius/web/security/oauth/ReceivedTokens.java

@@ -22,10 +22,12 @@
  * @param accessToken           the access token received from the authorization server
  * @param refreshToken          the refresh token received from the authorization server
  * @param type                  the type of the tokens received from the authorization server, e.g. "Bearer" or "MAC"
+ * @param accessTokenExpiresAt  the date at which the access token expires, might be null if the server response
+ *                              contains no information
  * @param refreshTokenExpiresAt the date at which the refresh token expires, might be estimated if no JWT bearer
  *                              token is given
  */
-public record ReceivedTokens(String accessToken, String refreshToken, String type,
+public record ReceivedTokens(String accessToken, String refreshToken, String type, LocalDateTime accessTokenExpiresAt,
                              LocalDateTime refreshTokenExpiresAt) {
 
     private static final long TWO_DAYS_IN_SECONDS = 2 * 24 * 60 * 60L;
@@ -41,26 +43,27 @@ public static ReceivedTokens fromJson(ObjectNode response) {
         String accessToken = response.required(OAuth.ACCESS_TOKEN).asText("");
         String refreshToken = response.required(OAuth.REFRESH_TOKEN).asText("");
         String type = response.required(OAuth.TOKEN_TYPE).asText("");
+        long accessTokenExpiresIn = response.path(OAuth.EXPIRES_IN).asLong(0L);
+        LocalDateTime accessTokenExpiresAt = LocalDateTime.now().plusSeconds(accessTokenExpiresIn);
         if (OAuth.TOKEN_TYPE_BEARER.equalsIgnoreCase(type)) {
             try {
                 // Try to read the exact refresh token expiration date from the JWT token itself
                 LocalDateTime refreshTokenExpiresAt =
                         JWT.decode(refreshToken).getExpiresAtAsInstant().atZone(ZoneOffset.UTC).toLocalDateTime();
-                return new ReceivedTokens(accessToken, refreshToken, type, refreshTokenExpiresAt);
+                return new ReceivedTokens(accessToken, refreshToken, type, accessTokenExpiresAt, refreshTokenExpiresAt);
             } catch (JWTDecodeException exception) {
                 // No valid JWT, fall back to implementation from OAuth expires_in or the default value
             }
         }
 
-        // Check if the 'expires in' field, actually meant for the access token, is better than our default tomorrow.
-        long expiresIn = response.path(OAuth.EXPIRES_IN).asLong(0L);
-        if (expiresIn > TWO_DAYS_IN_SECONDS) {
-            LocalDateTime expiresDate = LocalDateTime.now().plusSeconds(expiresIn);
-            return new ReceivedTokens(accessToken, refreshToken, type, expiresDate);
+        // Check if the 'expires in' field, actually meant for the access token, is better than our refresh token
+        // default expires value tomorrow.
+        if (accessTokenExpiresIn > TWO_DAYS_IN_SECONDS) {
+            return new ReceivedTokens(accessToken, refreshToken, type, accessTokenExpiresAt, accessTokenExpiresAt);
         }
 
         // Use default value tomorrow, we expect a refresh token to be valid at least for one more day
         LocalDateTime expiresDate = LocalDateTime.now().plusDays(MINIMUM_REFRESH_EXPIRES_DAYS);
-        return new ReceivedTokens(accessToken, refreshToken, type, expiresDate);
+        return new ReceivedTokens(accessToken, refreshToken, type, accessTokenExpiresAt, expiresDate);
     }
 }