Periodic sync, reload from memory if outdated

app/src/main/java/de/sebse/fuplanner/MainActivity.java

@@ -1,6 +1,7 @@
 package de.sebse.fuplanner;
 
 import android.accounts.AccountManager;
+import android.content.ContentResolver;
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.Menu;
@@ -39,12 +40,13 @@ import de.sebse.fuplanner.fragments.moddetails.ModDetailFragment;
 import de.sebse.fuplanner.services.canteen.CanteenBrowser;
 import de.sebse.fuplanner.services.canteen.types.Canteen;
 import de.sebse.fuplanner.services.canteen.types.CanteenListener;
+import de.sebse.fuplanner.services.fulogin.AccountGeneral;
 import de.sebse.fuplanner.services.kvv.KVV;
 import de.sebse.fuplanner.services.kvv.KVVListener;
+import de.sebse.fuplanner.services.kvv.sync.KVVContentProvider;
 import de.sebse.fuplanner.services.kvv.types.LoginToken;
 import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.services.news.NewsManager;
-import de.sebse.fuplanner.services.fulogin.AccountGeneral;
 import de.sebse.fuplanner.tools.CustomAccountManager;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.NewAsyncQueue;
@@ -136,6 +138,12 @@ public class MainActivity extends AppCompatActivity
                     changeFragment(getDefaultFragmentAfterLogout());
             });
         }
+        ContentResolver.addPeriodicSync(
+                mAccountManager.getAccountByType(AccountGeneral.ACCOUNT_TYPE),
+                KVVContentProvider.PROVIDER_NAME,
+                Bundle.EMPTY,
+                AccountGeneral.SYNC_INTERVAL);
+
     }
 
     @Override
@@ -158,6 +166,7 @@ public class MainActivity extends AppCompatActivity
                     changeFragment(getDefaultFragmentAfterLogout());
                 }
             });
+            getKVV().modules().list().reloadIfOutdated();
         }
         isPaused = false;
     }

app/src/main/java/de/sebse/fuplanner/services/fulogin/AccountGeneral.java

@@ -4,4 +4,5 @@ public class AccountGeneral {
     public static final String ACCOUNT_TYPE = "de.sebse.fuplanner.fuauth";
     public static final String AUTHTOKEN_TYPE_KVV = "KVV";
     public static final String AUTHTOKEN_TYPE_BLACKBOARD = "Blackboard";
+    public static final long SYNC_INTERVAL = 6 * 60 * 60; // defined in seconds
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesList.java

@@ -46,6 +46,16 @@ public class ModulesList extends HTTPService {
         return null;
     }
 
+    public void reloadIfOutdated() {
+        try {
+            if (mModules != null && mModules.isNewerVersionInStorage(getContext())) {
+                restore();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
     public void find(String moduleID, NetworkCallback<Modules.Module> moduleNetworkCallback, NetworkErrorCallback errorCallback) {
         find(moduleID, moduleNetworkCallback, errorCallback, RETRY_COUNT);
     }
@@ -115,10 +125,10 @@ public class ModulesList extends HTTPService {
             this.upgrade(success -> {
                 if (this.mModules == null)
                     this.mModules = success;
-                else
+                else if(this.mModules.updateList(success)) {
-                    this.mModules.updateList(success);
+                    mListener.onModuleListChange();
-                mListener.onModuleListChange();
+                    store();
-                store();
+                }
                 callback.onResponse(this.mModules);
                 mQueue.next();
             }, error -> {

app/src/main/java/de/sebse/fuplanner/services/kvv/sync/KVVContentProvider.java

@@ -11,7 +11,7 @@ import androidx.annotation.Nullable;
 
 public class KVVContentProvider extends ContentProvider {
 
-    private static final String PROVIDER_NAME = "de.sebse.fuplanner.contentprovider.kvv.modules";
+    public static final String PROVIDER_NAME = "de.sebse.fuplanner.contentprovider.kvv.modules";
     private static final Uri CONTENT_URI = Uri.parse("content://" + PROVIDER_NAME + "/modules");
     private static final int MODULE = 1;
     private static final int MODULE_ID = 2;

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Modules.java

@@ -2,6 +2,8 @@ package de.sebse.fuplanner.services.kvv.types;
 
 import android.content.Context;
 
+import com.google.android.gms.common.internal.Objects;
+
 import org.jetbrains.annotations.NotNull;
 
 import java.io.FileInputStream;
@@ -25,8 +27,10 @@ import androidx.annotation.Nullable;
 public class Modules implements Iterable<Modules.Module>, Serializable {
     private SortedListModule list;
     private final String mUsername;
+    private transient long mLastTimestamp = 0;
     //private transient Logger log = new Logger(this);
     private static final String FILE_NAME = "ModuleListSaving";
+    private static final String FILE_NAME_TIMESTAMP = "ModuleListSavingTimestamp";
 
     public Modules(String username) {
         this.mUsername = username;
@@ -75,15 +79,38 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
         Modules modules = (Modules) readObject;
         is.close();
         fis.close();
+
+        fis = context.openFileInput(FILE_NAME_TIMESTAMP);
+        is = new ObjectInputStream(fis);
+        modules.mLastTimestamp = is.readLong();
+        is.close();
+        fis.close();
+
         return modules;
     }
 
+    public boolean isNewerVersionInStorage(Context context) throws IOException {
+        FileInputStream fis = context.openFileInput(FILE_NAME_TIMESTAMP);
+        ObjectInputStream is = new ObjectInputStream(fis);
+        boolean result = this.mLastTimestamp < is.readLong();
+        is.close();
+        fis.close();
+        return result;
+    }
+
     public void save(Context context) throws IOException {
         FileOutputStream fos = context.openFileOutput(FILE_NAME, Context.MODE_PRIVATE);
         ObjectOutputStream os = new ObjectOutputStream(fos);
         os.writeObject(this);
         os.close();
         fos.close();
+
+        fos = context.openFileOutput(FILE_NAME_TIMESTAMP, Context.MODE_PRIVATE);
+        os = new ObjectOutputStream(fos);
+        this.mLastTimestamp = System.currentTimeMillis();
+        os.writeLong(this.mLastTimestamp);
+        os.close();
+        fos.close();
     }
 
     public void delete(Context context) {
@@ -94,19 +121,36 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
         return mUsername;
     }
 
-    public void updateList(Modules modules) {
+    public boolean updateList(Modules modules) {
         SortedListModule old = this.list;
         this.list = modules.list;
+        boolean isChanged = false;
         for (Module oldModule : old) {
             Module newModule = this.list.getById(oldModule.getID());
             if (newModule != null) {
+                if (!isChanged && !hashEquals(oldModule, newModule))
+                    isChanged = true;
                 newModule.announcements = oldModule.announcements;
                 newModule.assignments = oldModule.assignments;
                 newModule.events = oldModule.events;
                 newModule.gradebook = oldModule.gradebook;
                 newModule.resources = oldModule.resources;
+            } else {
+                isChanged = true;
             }
         }
+        if (this.list.size() != old.size())
+            isChanged = true;
+        return isChanged;
+    }
+
+    private boolean hashEquals(Module o1, Module o2) {
+        if (o1 == null && o2 == null)
+            return true;
+        else if (o1 == null || o2 == null)
+            return false;
+        else
+            return o1.hashCode() == o2.hashCode();
     }
 
     public class Module implements Serializable {
@@ -166,5 +210,10 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
                     "\ntype: "+type+
                     "\nID: "+ID;
         }
+
+        @Override
+        public int hashCode() {
+            return Objects.hashCode(semester, lvNumber, title, lecturer, type, description, ID);
+        }
     }
 }

app/src/main/java/de/sebse/fuplanner/tools/CustomAccountManager.java

@@ -122,6 +122,13 @@ public class CustomAccountManager {
         return mAccountManager.getAccountsByType(accountType).length != 0;
     }
 
+    public Account getAccountByType(String accountType) {
+        Account[] accountsByType = mAccountManager.getAccountsByType(accountType);
+        if (accountsByType.length > 0)
+            return accountsByType[0];
+        return null;
+    }
+
     @FunctionalInterface
     public interface ActivityInterface {
         @Nullable