Pre expire tokens

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

@@ -309,7 +309,7 @@ public class EmailService implements AutoCloseable {
     public void connect(EntityAccount account) throws MessagingException {
         connect(
                 account.host, account.port,
-                account.auth_type, account.provider,
+                account.auth_type, account.provider, account.poll_interval,
                 account.user, account.password,
                 new ServiceAuthenticator.IAuthenticated() {
                     @Override
@@ -326,7 +326,7 @@ public class EmailService implements AutoCloseable {
     public void connect(EntityIdentity identity) throws MessagingException {
         connect(
                 identity.host, identity.port,
-                identity.auth_type, identity.provider,
+                identity.auth_type, identity.provider, 0,
                 identity.user, identity.password,
                 new ServiceAuthenticator.IAuthenticated() {
                     @Override
@@ -342,14 +342,16 @@ public class EmailService implements AutoCloseable {
 
     public void connect(
             String host, int port,
-            int auth, String provider, String user, String password,
+            int auth, String provider,
+            String user, String password,
             String certificate, String fingerprint) throws MessagingException {
-        connect(host, port, auth, provider, user, password, null, certificate, fingerprint);
+        connect(host, port, auth, provider, 0, user, password, null, certificate, fingerprint);
     }
 
     private void connect(
             String host, int port,
-            int auth, String provider, String user, String password,
+            int auth, String provider, int keep_alive,
+            String user, String password,
             ServiceAuthenticator.IAuthenticated intf,
             String certificate, String fingerprint) throws MessagingException {
         SSLSocketFactoryService factory = null;
@@ -378,7 +380,8 @@ public class EmailService implements AutoCloseable {
         }
 
         properties.put("mail." + protocol + ".forcepasswordrefresh", "true");
-        ServiceAuthenticator authenticator = new ServiceAuthenticator(context, auth, provider, user, password, intf);
+        ServiceAuthenticator authenticator = new ServiceAuthenticator(context,
+                auth, provider, keep_alive, user, password, intf);
 
         try {
             if (auth == AUTH_TYPE_GMAIL || auth == AUTH_TYPE_OAUTH) {

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

@@ -60,8 +60,17 @@ public class GmailState {
             return acquired + TOKEN_LIFETIME;
     }
 
-    void refresh(@NonNull Context context, @NonNull String user, boolean expire) throws AuthenticatorException, OperationCanceledException, IOException {
+    void refresh(@NonNull Context context, @NonNull String user, boolean expire, long keep_alive)
-        if (expire || acquired + TOKEN_LIFETIME < new Date().getTime())
+            throws AuthenticatorException, OperationCanceledException, IOException {
+        Long expiration = getAccessTokenExpirationTime();
+        if (expiration != null && expiration - keep_alive < new Date().getTime()) {
+            EntityLog.log(context, "Force invalidation" +
+                    " expiration=" + new Date(expiration) +
+                    " keep-alive=" + (keep_alive / 60 / 1000) + "m");
+            expire = true;
+        }
+
+        if (expire)
             try {
                 if (token != null) {
                     EntityLog.log(context, "Invalidating token user=" + user);

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

@@ -47,6 +47,7 @@ public class ServiceAuthenticator extends Authenticator {
     private Context context;
     private int auth;
     private String provider;
+    private long keep_alive;
     private String user;
     private String password;
     private IAuthenticated intf;
@@ -57,12 +58,13 @@ public class ServiceAuthenticator extends Authenticator {
 
     ServiceAuthenticator(
             Context context,
-            int auth, String provider,
+            int auth, String provider, int keep_alive,
             String user, String password,
             IAuthenticated intf) {
         this.context = context.getApplicationContext();
         this.auth = auth;
         this.provider = provider;
+        this.keep_alive = keep_alive * 60 * 1000L;
         this.user = user;
         this.password = password;
         this.intf = intf;
@@ -87,7 +89,7 @@ public class ServiceAuthenticator extends Authenticator {
     String refreshToken(boolean expire) throws AuthenticatorException, OperationCanceledException, IOException, JSONException, MessagingException {
         if (auth == AUTH_TYPE_GMAIL) {
             GmailState authState = GmailState.jsonDeserialize(password);
-            authState.refresh(context, user, expire);
+            authState.refresh(context, user, expire, keep_alive);
             Long expiration = authState.getAccessTokenExpirationTime();
             if (expiration != null)
                 EntityLog.log(context, user + " token expiration=" + new Date(expiration));
@@ -102,9 +104,7 @@ public class ServiceAuthenticator extends Authenticator {
             return authState.getAccessToken();
         } else if (auth == AUTH_TYPE_OAUTH) {
             AuthState authState = AuthState.jsonDeserialize(password);
-            if (expire)
+            OAuthRefresh(context, provider, authState, expire, keep_alive);
-                authState.setNeedsTokenRefresh(true);
-            OAuthRefresh(context, provider, authState);
             Long expiration = authState.getAccessTokenExpirationTime();
             if (expiration != null)
                 EntityLog.log(context, user + " token expiration=" + new Date(expiration));
@@ -125,8 +125,20 @@ public class ServiceAuthenticator extends Authenticator {
         void onPasswordChanged(String newPassword);
     }
 
-    private static void OAuthRefresh(Context context, String id, AuthState authState) throws MessagingException {
+    private static void OAuthRefresh(Context context, String id, AuthState authState, boolean expire, long keep_alive)
+            throws MessagingException {
         try {
+            Long expiration = authState.getAccessTokenExpirationTime();
+            if (expiration != null && expiration - keep_alive < new Date().getTime()) {
+                EntityLog.log(context, "OAuth force refresh" +
+                        " expiration=" + new Date(expiration) +
+                        " keep_alive=" + (keep_alive / 60 / 1000) + "m");
+                authState.setNeedsTokenRefresh(true);
+            }
+
+            if (expire)
+                authState.setNeedsTokenRefresh(true);
+
             ClientAuthentication clientAuth;
             EmailProvider provider = EmailProvider.getProvider(context, id);
             if (provider.oauth.clientSecret == null)