Merge pull request #755 from rivaldi8/cl-555-books-db-empty

Recover from empty books database

Author: codinguser

app/src/main/java/org/gnucash/android/app/GnuCashApplication.java

@@ -150,7 +150,7 @@ public static void initializeDatabaseAdapters() {
             mDbHelper = new DatabaseHelper(getAppContext(),
                                            mBooksDbAdapter.getActiveBookUID());
         } catch (BooksDbAdapter.NoActiveBookFoundException e) {
-            fixBooksDatabase();
+            mBooksDbAdapter.fixBooksDatabase();
             mDbHelper = new DatabaseHelper(getAppContext(),
                                            mBooksDbAdapter.getActiveBookUID());
         }
@@ -174,13 +174,6 @@ public static void initializeDatabaseAdapters() {
         mBudgetsDbAdapter           = new BudgetsDbAdapter(mainDb, mBudgetAmountsDbAdapter, mRecurrenceDbAdapter);
     }
 
-    /** Sets the first book in the database as active. */
-    private static void fixBooksDatabase() {
-        Book firstBook = BooksDbAdapter.getInstance().getAllRecords().get(0);
-        firstBook.setActive(true);
-        BooksDbAdapter.getInstance().addRecord(firstBook);
-    }
-
     public static AccountsDbAdapter getAccountsDbAdapter() {
         return mAccountsDbAdapter;
     }

app/src/main/java/org/gnucash/android/db/adapter/BooksDbAdapter.java

@@ -23,9 +23,11 @@
 import android.database.sqlite.SQLiteStatement;
 import android.net.Uri;
 import android.support.annotation.NonNull;
+import android.util.Log;
 
 import org.gnucash.android.R;
 import org.gnucash.android.app.GnuCashApplication;
+import org.gnucash.android.db.DatabaseHelper;
 import org.gnucash.android.db.DatabaseSchema.BookEntry;
 import org.gnucash.android.model.Book;
 import org.gnucash.android.ui.settings.PreferenceActivity;
@@ -190,6 +192,72 @@ public NoActiveBookFoundException(String message) {
         }
     }
 
+    /** Tries to fix the books database. */
+    public void fixBooksDatabase() {
+        Log.w(LOG_TAG, "Looking for books to set as active...");
+        if (getRecordsCount() <= 0) {
+            Log.w(LOG_TAG, "No books found in the database. Recovering books records...");
+            recoverBookRecords();
+        }
+        setFirstBookAsActive();
+    }
+
+    /**
+     * Restores the records in the book database.
+     *
+     * Does so by looking for database files from books.
+     */
+    private void recoverBookRecords() {
+        for (String dbName : getBookDatabases()) {
+            Book book = new Book(getRootAccountUID(dbName));
+            book.setUID(dbName);
+            book.setDisplayName(generateDefaultBookName());
+            addRecord(book);
+            Log.w(LOG_TAG, "Recovered book record: " + book.getUID());
+        }
+    }
+
+    /**
+     * Returns the root account UID from the database with name dbName.
+     */
+    private String getRootAccountUID(String dbName) {
+        Context context = GnuCashApplication.getAppContext();
+        DatabaseHelper databaseHelper = new DatabaseHelper(context, dbName);
+        SQLiteDatabase db = databaseHelper.getReadableDatabase();
+        AccountsDbAdapter accountsDbAdapter = new AccountsDbAdapter(db,
+                new TransactionsDbAdapter(db, new SplitsDbAdapter(db)));
+        String uid = accountsDbAdapter.getOrCreateGnuCashRootAccountUID();
+        db.close();
+        return uid;
+    }
+
+    /**
+     * Sets the first book in the database as active.
+     */
+    private void setFirstBookAsActive() {
+        Book firstBook = getAllRecords().get(0);
+        firstBook.setActive(true);
+        addRecord(firstBook);
+        Log.w(LOG_TAG, "Book " + firstBook.getUID() + " set as active.");
+    }
+
+    /**
+     * Returns a list of database names corresponding to book databases.
+     */
+    private List<String> getBookDatabases() {
+        List<String> bookDatabases = new ArrayList<>();
+        for (String database : GnuCashApplication.getAppContext().databaseList()) {
+            if (isBookDatabase(database)) {
+                bookDatabases.add(database);
+            }
+        }
+        return bookDatabases;
+    }
+
+    private boolean isBookDatabase(String databaseName) {
+        return databaseName.matches("[a-z0-9]{32}"); // UID regex
+    }
+
     public @NonNull List<String> getAllBookUIDs(){
         List<String> bookUIDs = new ArrayList<>();
         try (Cursor cursor = mDb.query(true, mTableName, new String[]{BookEntry.COLUMN_UID},

app/src/test/java/org/gnucash/android/test/unit/db/BooksDbAdapterTest.java

@@ -36,6 +36,7 @@
 
 import javax.xml.parsers.ParserConfigurationException;
 
+import static junit.framework.Assert.fail;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -158,6 +159,42 @@ public void testGeneratedDisplayNames_shouldBeUnique(){
         assertThat(generatedName).isEqualTo("Book 4");
     }
 
+    @Test
+    public void recoverFromNoActiveBookFound() {
+        Book book1 = new Book(BaseModel.generateUID());
+        book1.setActive(false);
+        mBooksDbAdapter.addRecord(book1);
+
+        Book book2 = new Book(BaseModel.generateUID());
+        book2.setActive(false);
+        mBooksDbAdapter.addRecord(book2);
+
+        try {
+            mBooksDbAdapter.getActiveBookUID();
+            fail("There shouldn't be any active book.");
+        } catch (BooksDbAdapter.NoActiveBookFoundException e) {
+            mBooksDbAdapter.fixBooksDatabase();
+        }
+
+        assertThat(mBooksDbAdapter.getActiveBookUID()).isEqualTo(book1.getUID());
+    }
+
+    /**
+     * Tests the recovery from an empty books database.
+     */
+    @Test
+    public void recoverFromEmptyDatabase() {
+        createNewBookWithDefaultAccounts();
+        mBooksDbAdapter.deleteAllRecords();
+        assertThat(mBooksDbAdapter.getRecordsCount()).isZero();
+
+        mBooksDbAdapter.fixBooksDatabase();
+
+        // Should've recovered the one from setUp() plus the one created above
+        assertThat(mBooksDbAdapter.getRecordsCount()).isEqualTo(2);
+        mBooksDbAdapter.getActiveBookUID(); // should not throw exception
+    }
+
     /**
      * Creates a new database with default accounts
      * @return The book UID for the new database