feat: add version upgrade functionality

app/src/main/java/ai/elimu/content_provider/BaseApplication.java

@@ -3,7 +3,8 @@
 import android.app.Application;
 import android.util.Log;
 
-import ai.elimu.content_provider.language.SharedPreferencesHelper;
+import ai.elimu.content_provider.util.SharedPreferencesHelper;
+import ai.elimu.content_provider.util.VersionHelper;
 import ai.elimu.model.v2.enums.Language;
 import retrofit2.Retrofit;
 import retrofit2.converter.gson.GsonConverterFactory;
@@ -14,6 +15,8 @@ public class BaseApplication extends Application {
     public void onCreate() {
         Log.i(getClass().getName(), "onCreate");
         super.onCreate();
+
+        VersionHelper.updateAppVersion(getApplicationContext());
     }
 
     public Retrofit getRetrofit() {

app/src/main/java/ai/elimu/content_provider/MainActivity.java

@@ -18,7 +18,7 @@
 import com.google.android.material.navigation.NavigationView;
 
 import ai.elimu.content_provider.language.SelectLanguageActivity;
-import ai.elimu.content_provider.language.SharedPreferencesHelper;
+import ai.elimu.content_provider.util.SharedPreferencesHelper;
 import ai.elimu.model.v2.enums.Language;
 
 public class MainActivity extends AppCompatActivity {

app/src/main/java/ai/elimu/content_provider/language/LanguageListDialogFragment.java

@@ -1,8 +1,6 @@
 package ai.elimu.content_provider.language;
 
-import android.content.Context;
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -18,6 +16,7 @@
 
 import ai.elimu.content_provider.MainActivity;
 import ai.elimu.content_provider.R;
+import ai.elimu.content_provider.util.SharedPreferencesHelper;
 import ai.elimu.model.v2.enums.Language;
 
 /**
@@ -84,8 +83,7 @@ public void onBindViewHolder(ViewHolder holder, int position) {
                 public void onClick(View v) {
                     Log.i(getClass().getName(), "onClick");
                     Log.i(getClass().getName(), "language: " + language);
-                    SharedPreferences sharedPreferences = getActivity().getSharedPreferences("shared_preferences", Context.MODE_PRIVATE);
-                    sharedPreferences.edit().putString("language", language.toString()).apply();
+                    SharedPreferencesHelper.storeLanguage(getContext(), language);
                     Intent mainActivityIntent = new Intent(getContext(), MainActivity.class);
                     startActivity(mainActivityIntent);
                     getActivity().finish();

app/src/main/java/ai/elimu/content_provider/util/SharedPreferencesHelper.java

@@ -0,0 +1,51 @@
+package ai.elimu.content_provider.util;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.text.TextUtils;
+
+import ai.elimu.model.v2.enums.Language;
+
+public class SharedPreferencesHelper {
+
+    public static final String SHARED_PREFS = "shared_prefs";
+
+    public static final String PREF_APP_VERSION_CODE = "pref_app_version_code";
+    public static final String PREF_LANGUAGE = "pref_language";
+
+    public static void clearAllPreferences(Context context) {
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
+        sharedPreferences.edit().clear().apply();
+    }
+
+
+    public static void storeAppVersionCode(Context context, int appVersionCode) {
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
+        sharedPreferences.edit().putInt(PREF_APP_VERSION_CODE, appVersionCode).apply();
+    }
+
+    public static int getAppVersionCode(Context context) {
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
+        return sharedPreferences.getInt(PREF_APP_VERSION_CODE, 0);
+    }
+
+
+    public static void storeLanguage(Context context, Language language) {
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
+        sharedPreferences.edit().putString(PREF_LANGUAGE, language.toString()).apply();
+    }
+
+    public static Language getLanguage(Context context) {
+        SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
+        String languageAsString = sharedPreferences.getString(PREF_LANGUAGE, null);
+        if (TextUtils.isEmpty(languageAsString)) {
+            return null;
+        } else {
+            try {
+                return Language.valueOf(languageAsString);
+            } catch (IllegalArgumentException e) {
+                return null;
+            }
+        }
+    }
+}

app/src/main/java/ai/elimu/content_provider/util/VersionHelper.java

@@ -0,0 +1,52 @@
+package ai.elimu.content_provider.util;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.util.Log;
+
+/**
+ * Helps detect upgrades from previously installed versions of the app.
+ */
+public class VersionHelper {
+
+    public static int getAppVersionCode(Context context) {
+        Log.i(VersionHelper.class.getName(), "getAppVersionCode");
+
+        try {
+            PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
+            return packageInfo.versionCode;
+        } catch (PackageManager.NameNotFoundException e) {
+            throw new RuntimeException("Could not get package name: " + e);
+        }
+    }
+
+    /**
+     * Stores the version code of the application currently installed. And detects upgrades from previously installed
+     * versions.
+     */
+    public static void updateAppVersion(Context context) {
+        Log.i(VersionHelper.class.getName(), "updateAppVersion");
+
+        // Check if the application's versionCode was upgraded
+        int oldVersionCode = SharedPreferencesHelper.getAppVersionCode(context);
+        int newVersionCode = VersionHelper.getAppVersionCode(context);
+        if (oldVersionCode == 0) {
+            SharedPreferencesHelper.storeAppVersionCode(context, newVersionCode);
+            oldVersionCode = newVersionCode;
+        }
+        Log.i(VersionHelper.class.getName(),"oldVersionCode: " + oldVersionCode);
+        Log.i(VersionHelper.class.getName(),"newVersionCode: " + newVersionCode);
+
+        // Handle upgrade from previous version
+        if (oldVersionCode < newVersionCode) {
+            Log.i(VersionHelper.class.getName(), "Upgrading application from version " + oldVersionCode + " to " + newVersionCode + "...");
+
+//            if (oldVersionCode < ???) {
+//                ...
+//            }
+
+            SharedPreferencesHelper.storeAppVersionCode(context, newVersionCode);
+        }
+    }
+}