session-android/src/org/thoughtcrime/securesms/database/MessagingDatabase.java

package org.thoughtcrime.securesms.database;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.text.TextUtils;
import android.util.Log;

import org.thoughtcrime.securesms.database.documents.Document;
import org.thoughtcrime.securesms.database.documents.IdentityKeyMismatch;
import org.thoughtcrime.securesms.database.documents.IdentityKeyMismatchList;
import org.thoughtcrime.securesms.util.JsonUtils;
import org.whispersystems.libaxolotl.IdentityKey;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

public abstract class MessagingDatabase extends Database implements MmsSmsColumns {

  private static final String TAG = MessagingDatabase.class.getSimpleName();

  public MessagingDatabase(Context context, SQLiteOpenHelper databaseHelper) {
    super(context, databaseHelper);
  }

  protected abstract String getTableName();

  public void addMismatchedIdentity(long messageId, long recipientId, IdentityKey identityKey) {
    try {
      addToDocument(messageId, MISMATCHED_IDENTITIES,
                    new IdentityKeyMismatch(recipientId, identityKey),
                    IdentityKeyMismatchList.class);
    } catch (IOException e) {
      Log.w(TAG, e);
    }
  }

  public void removeMismatchedIdentity(long messageId, long recipientId, IdentityKey identityKey) {
    try {
      removeFromDocument(messageId, MISMATCHED_IDENTITIES,
                         new IdentityKeyMismatch(recipientId, identityKey),
                         IdentityKeyMismatchList.class);
    } catch (IOException e) {
      Log.w(TAG, e);
    }
  }

  protected <D extends Document<I>, I> void removeFromDocument(long messageId, String column, I object, Class<D> clazz) throws IOException {
    SQLiteDatabase database = databaseHelper.getWritableDatabase();
    database.beginTransaction();

    try {
      D           document = getDocument(database, messageId, column, clazz);
      Iterator<I> iterator = document.getList().iterator();

      while (iterator.hasNext()) {
        I item = iterator.next();

        if (item.equals(object)) {
          iterator.remove();
          break;
        }
      }

      setDocument(database, messageId, column, document);
      database.setTransactionSuccessful();
    } finally {
      database.endTransaction();
    }
  }

  protected <T extends Document<I>, I> void addToDocument(long messageId, String column, final I object, Class<T> clazz) throws IOException {
    List<I> list = new ArrayList<I>() {{
      add(object);
    }};

    addToDocument(messageId, column, list, clazz);
  }

  protected <T extends Document<I>, I> void addToDocument(long messageId, String column, List<I> objects, Class<T> clazz) throws IOException {
    SQLiteDatabase database = databaseHelper.getWritableDatabase();
    database.beginTransaction();

    try {
      T document = getDocument(database, messageId, column, clazz);
      document.getList().addAll(objects);
      setDocument(database, messageId, column, document);

      database.setTransactionSuccessful();
    } finally {
      database.endTransaction();
    }
  }

  private void setDocument(SQLiteDatabase database, long messageId, String column, Document document) throws IOException {
    ContentValues contentValues = new ContentValues();

    if (document == null || document.size() == 0) {
      contentValues.put(column, (String)null);
    } else {
      contentValues.put(column, JsonUtils.toJson(document));
    }

    database.update(getTableName(), contentValues, ID_WHERE, new String[] {String.valueOf(messageId)});
  }

  private <D extends Document> D getDocument(SQLiteDatabase database, long messageId,
                                             String column, Class<D> clazz)
  {
    Cursor cursor = null;

    try {
      cursor = database.query(getTableName(), new String[] {column},
                              ID_WHERE, new String[] {String.valueOf(messageId)},
                              null, null, null);

      if (cursor != null && cursor.moveToNext()) {
        String document = cursor.getString(cursor.getColumnIndexOrThrow(column));

        try {
          if (!TextUtils.isEmpty(document)) {
            return JsonUtils.fromJson(document, clazz);
          }
        } catch (IOException e) {
          Log.w(TAG, e);
        }
      }

      try {
        return clazz.newInstance();
      } catch (InstantiationException | IllegalAccessException e) {
        throw new AssertionError(e);
      }

    } finally {
      if (cursor != null)
        cursor.close();
    }
  }
}