Expedite keep alive time for token refresh

app/src/main/java/eu/faircode/email/EmailService.java

@@ -889,8 +889,8 @@ public class EmailService implements AutoCloseable {
             return false;
     }
 
-    public void check() {
+    public Long getAccessTokenExpirationTime() {
-        authenticator.checkToken();
+        return authenticator.getAccessTokenExpirationTime();
     }
 
     public boolean isOpen() {

app/src/main/java/eu/faircode/email/ServiceAuthenticator.java

@@ -56,7 +56,7 @@ public class ServiceAuthenticator extends Authenticator {
     static final int AUTH_TYPE_GMAIL = 2;
     static final int AUTH_TYPE_OAUTH = 3;
 
-    static final long MIN_EXPIRE_INTERVAL = 12 * 60 * 1000L;
+    static final long MIN_EXPIRE_INTERVAL = 15 * 60 * 1000L;
 
     ServiceAuthenticator(
             Context context,
@@ -125,24 +125,19 @@ public class ServiceAuthenticator extends Authenticator {
             return password;
     }
 
-    void checkToken() {
+    Long getAccessTokenExpirationTime() {
-        Long expiration = null;
-
         try {
             if (auth == AUTH_TYPE_GMAIL) {
                 GmailState authState = GmailState.jsonDeserialize(password);
-                expiration = authState.getAccessTokenExpirationTime();
+                return authState.getAccessTokenExpirationTime();
             } else if (auth == AUTH_TYPE_OAUTH) {
                 AuthState authState = AuthState.jsonDeserialize(password);
-                expiration = authState.getAccessTokenExpirationTime();
+                return authState.getAccessTokenExpirationTime();
             }
         } catch (JSONException ex) {
             Log.e(ex);
         }
-
+        return null;
-        long slack = Math.min(keep_alive, MIN_EXPIRE_INTERVAL);
-        if (expiration != null && expiration - slack < new Date().getTime())
-            throw new IllegalStateException(Log.TOKEN_REFRESH_REQUIRED);
     }
 
     interface IAuthenticated {

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -2239,10 +2239,6 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                                 throw new StoreClosedException(iservice.getStore(), "Unrecoverable", cause);
                             }
 
-                            // Check token expiration
-                            if (!account.isTransient(this))
-                                iservice.check();
-
                             // Sends store NOOP
                             if (EmailService.SEPARATE_STORE_CONNECTION) {
                                 EntityLog.log(this, EntityLog.Type.Account, account,
@@ -2357,6 +2353,16 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                         try {
                             long duration = account.poll_interval * 60 * 1000L;
                             long trigger = System.currentTimeMillis() + duration;
+
+                            if (!account.isTransient(this)) {
+                                Long expirationTime = iservice.getAccessTokenExpirationTime();
+                                if (expirationTime != null && expirationTime < trigger) {
+                                    EntityLog.log(this, EntityLog.Type.Debug, "Expedite keep alive" +
+                                            " from " + new Date(trigger) + " to " + new Date(expirationTime));
+                                    trigger = expirationTime;
+                                }
+                            }
+
                             EntityLog.log(this, EntityLog.Type.Account, account,
                                     "### " + account.name + " keep alive" +
                                             " wait=" + account.poll_interval + " until=" + new Date(trigger));