Signal-Android/src/org/thoughtcrime/securesms/database/AttachmentDatabase.java

/**
 * Copyright (C) 2011 Whisper Systems
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
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.graphics.Bitmap;
import android.media.MediaMetadataRetriever;
import android.net.Uri;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.annotation.VisibleForTesting;
import android.text.TextUtils;
import android.util.Log;
import android.util.Pair;

import org.thoughtcrime.securesms.ApplicationContext;
import org.thoughtcrime.securesms.attachments.Attachment;
import org.thoughtcrime.securesms.attachments.AttachmentId;
import org.thoughtcrime.securesms.attachments.DatabaseAttachment;
import org.thoughtcrime.securesms.crypto.AsymmetricMasterCipher;
import org.thoughtcrime.securesms.crypto.DecryptingPartInputStream;
import org.thoughtcrime.securesms.crypto.EncryptingPartOutputStream;
import org.thoughtcrime.securesms.crypto.MasterCipher;
import org.thoughtcrime.securesms.crypto.MasterSecret;
import org.thoughtcrime.securesms.crypto.MasterSecretUnion;
import org.thoughtcrime.securesms.mms.MediaStream;
import org.thoughtcrime.securesms.mms.PartAuthority;
import org.thoughtcrime.securesms.util.MediaUtil;
import org.thoughtcrime.securesms.util.MediaUtil.ThumbnailData;
import org.thoughtcrime.securesms.util.Util;
import org.thoughtcrime.securesms.video.EncryptedMediaDataSource;
import org.whispersystems.libsignal.InvalidMessageException;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;

import ws.com.google.android.mms.ContentType;
import ws.com.google.android.mms.MmsException;

public class AttachmentDatabase extends Database {
  
  private static final String TAG = AttachmentDatabase.class.getSimpleName();

          static final String TABLE_NAME             = "part";
          static final String ROW_ID                 = "_id";
          static final String ATTACHMENT_ID_ALIAS    = "attachment_id";
          static final String MMS_ID                 = "mid";
          static final String CONTENT_TYPE           = "ct";
          static final String NAME                   = "name";
          static final String CONTENT_DISPOSITION    = "cd";
          static final String CONTENT_LOCATION       = "cl";
          static final String DATA                   = "_data";
          static final String TRANSFER_STATE         = "pending_push";
          static final String SIZE                   = "data_size";
          static final String FILE_NAME              = "file_name";
          static final String THUMBNAIL              = "thumbnail";
          static final String THUMBNAIL_ASPECT_RATIO = "aspect_ratio";
          static final String UNIQUE_ID              = "unique_id";
          static final String DIGEST                 = "digest";

  public static final int TRANSFER_PROGRESS_DONE         = 0;
  public static final int TRANSFER_PROGRESS_STARTED      = 1;
  public static final int TRANSFER_PROGRESS_AUTO_PENDING = 2;
  public static final int TRANSFER_PROGRESS_FAILED       = 3;

  private static final String PART_ID_WHERE = ROW_ID + " = ? AND " + UNIQUE_ID + " = ?";

  private static final String[] PROJECTION = new String[] {ROW_ID + " AS " + ATTACHMENT_ID_ALIAS,
                                                           MMS_ID, CONTENT_TYPE, NAME, CONTENT_DISPOSITION,
                                                           CONTENT_LOCATION, DATA, THUMBNAIL, TRANSFER_STATE,
                                                           SIZE, FILE_NAME, THUMBNAIL, THUMBNAIL_ASPECT_RATIO,
                                                           UNIQUE_ID, DIGEST};

  public static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + " (" + ROW_ID + " INTEGER PRIMARY KEY, " +
    MMS_ID + " INTEGER, " + "seq" + " INTEGER DEFAULT 0, "                        +
    CONTENT_TYPE + " TEXT, " + NAME + " TEXT, " + "chset" + " INTEGER, "             +
    CONTENT_DISPOSITION + " TEXT, " + "fn" + " TEXT, " + "cid" + " TEXT, "  +
    CONTENT_LOCATION + " TEXT, " + "ctt_s" + " INTEGER, "                 +
    "ctt_t" + " TEXT, " + "encrypted" + " INTEGER, "                         +
    TRANSFER_STATE + " INTEGER, "+ DATA + " TEXT, " + SIZE + " INTEGER, "   +
    FILE_NAME + " TEXT, " + THUMBNAIL + " TEXT, " + THUMBNAIL_ASPECT_RATIO + " REAL, " +
    UNIQUE_ID + " INTEGER NOT NULL, " + DIGEST + " BLOB);";

  public static final String[] CREATE_INDEXS = {
    "CREATE INDEX IF NOT EXISTS part_mms_id_index ON " + TABLE_NAME + " (" + MMS_ID + ");",
    "CREATE INDEX IF NOT EXISTS pending_push_index ON " + TABLE_NAME + " (" + TRANSFER_STATE + ");",
  };

  private final ExecutorService thumbnailExecutor = Util.newSingleThreadedLifoExecutor();

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

  public @NonNull InputStream getAttachmentStream(MasterSecret masterSecret, AttachmentId attachmentId)
      throws IOException
  {
    InputStream dataStream = getDataStream(masterSecret, attachmentId, DATA);

    if (dataStream == null) throw new IOException("No stream for: " + attachmentId);
    else                    return dataStream;
  }

  public @NonNull InputStream getThumbnailStream(@NonNull MasterSecret masterSecret, @NonNull AttachmentId attachmentId)
      throws IOException
  {
    Log.w(TAG, "getThumbnailStream(" + attachmentId + ")");
    InputStream dataStream = getDataStream(masterSecret, attachmentId, THUMBNAIL);

    if (dataStream != null) {
      return dataStream;
    }

    try {
      InputStream generatedStream = thumbnailExecutor.submit(new ThumbnailFetchCallable(masterSecret, attachmentId)).get();

      if (generatedStream == null) throw new FileNotFoundException("No thumbnail stream available: " + attachmentId);
      else                         return generatedStream;
    } catch (InterruptedException ie) {
      throw new AssertionError("interrupted");
    } catch (ExecutionException ee) {
      Log.w(TAG, ee);
      throw new IOException(ee);
    }
  }

  public void setTransferProgressFailed(AttachmentId attachmentId, long mmsId)
      throws MmsException
  {
    SQLiteDatabase database = databaseHelper.getWritableDatabase();
    ContentValues  values   = new ContentValues();
    values.put(TRANSFER_STATE, TRANSFER_PROGRESS_FAILED);

    database.update(TABLE_NAME, values, PART_ID_WHERE, attachmentId.toStrings());
    notifyConversationListeners(DatabaseFactory.getMmsDatabase(context).getThreadIdForMessage(mmsId));
  }

  public @Nullable DatabaseAttachment getAttachment(@Nullable MasterSecret masterSecret, AttachmentId attachmentId)
  {
    SQLiteDatabase database = databaseHelper.getReadableDatabase();
    Cursor cursor           = null;

    try {
      cursor = database.query(TABLE_NAME, PROJECTION, PART_ID_WHERE, attachmentId.toStrings(), null, null, null);

      if (cursor != null && cursor.moveToFirst()) return getAttachment(masterSecret, cursor);
      else                                        return null;

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

  public @NonNull List<DatabaseAttachment> getAttachmentsForMessage(@Nullable MasterSecret masterSecret, long mmsId) {
    SQLiteDatabase           database = databaseHelper.getReadableDatabase();
    List<DatabaseAttachment> results  = new LinkedList<>();
    Cursor                   cursor   = null;

    try {
      cursor = database.query(TABLE_NAME, PROJECTION, MMS_ID + " = ?", new String[] {mmsId+""},
                              null, null, null);

      while (cursor != null && cursor.moveToNext()) {
        results.add(getAttachment(masterSecret, cursor));
      }

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

  public @NonNull List<DatabaseAttachment> getPendingAttachments(@NonNull MasterSecret masterSecret) {
    final SQLiteDatabase           database    = databaseHelper.getReadableDatabase();
    final List<DatabaseAttachment> attachments = new LinkedList<>();

    Cursor cursor = null;
    try {
      cursor = database.query(TABLE_NAME, PROJECTION, TRANSFER_STATE + " = ?", new String[] {String.valueOf(TRANSFER_PROGRESS_STARTED)}, null, null, null);
      while (cursor != null && cursor.moveToNext()) {
        attachments.add(getAttachment(masterSecret, cursor));
      }
    } finally {
      if (cursor != null) cursor.close();
    }

    return attachments;
  }

  @SuppressWarnings("ResultOfMethodCallIgnored")
  public void deleteAttachmentsForMessage(long mmsId) {
    SQLiteDatabase database = databaseHelper.getWritableDatabase();
    Cursor cursor           = null;

    try {
      cursor = database.query(TABLE_NAME, new String[] {DATA, THUMBNAIL}, MMS_ID + " = ?",
                              new String[] {mmsId+""}, null, null, null);

      while (cursor != null && cursor.moveToNext()) {
        String data = cursor.getString(0);
        String thumbnail = cursor.getString(1);

        if (!TextUtils.isEmpty(data)) {
          new File(data).delete();
        }

        if (!TextUtils.isEmpty(thumbnail)) {
          new File(thumbnail).delete();
        }
      }
    } finally {
      if (cursor != null)
        cursor.close();
    }

    database.delete(TABLE_NAME, MMS_ID + " = ?", new String[] {mmsId + ""});
  }

  @SuppressWarnings("ResultOfMethodCallIgnored")
  public void deleteAllAttachments() {
    SQLiteDatabase database = databaseHelper.getWritableDatabase();
    database.delete(TABLE_NAME, null, null);

    File   attachmentsDirectory = context.getDir("parts", Context.MODE_PRIVATE);
    File[] attachments          = attachmentsDirectory.listFiles();

    for (File attachment : attachments) {
      attachment.delete();
    }
  }

  public long insertAttachmentsForPlaceholder(@NonNull MasterSecret masterSecret, long mmsId,
                                              @NonNull AttachmentId attachmentId,
                                              @NonNull InputStream inputStream)
      throws MmsException
  {
    SQLiteDatabase   database = databaseHelper.getWritableDatabase();
    Pair<File, Long> partData = setAttachmentData(masterSecret, inputStream);
    ContentValues    values   = new ContentValues();

    values.put(DATA, partData.first.getAbsolutePath());
    values.put(SIZE, partData.second);
    values.put(TRANSFER_STATE, TRANSFER_PROGRESS_DONE);
    values.put(CONTENT_LOCATION, (String)null);
    values.put(CONTENT_DISPOSITION, (String)null);
    values.put(DIGEST, (byte[])null);
    values.put(NAME, (String) null);

    if (database.update(TABLE_NAME, values, PART_ID_WHERE, attachmentId.toStrings()) == 0) {
      //noinspection ResultOfMethodCallIgnored
      partData.first.delete();
    } else {
      notifyConversationListeners(DatabaseFactory.getMmsDatabase(context).getThreadIdForMessage(mmsId));
      notifyConversationListListeners();
    }

    thumbnailExecutor.submit(new ThumbnailFetchCallable(masterSecret, attachmentId));
    return partData.second;
  }

  void insertAttachmentsForMessage(@NonNull MasterSecretUnion masterSecret,
                                   long mmsId,
                                   @NonNull List<Attachment> attachments)
      throws MmsException
  {
    Log.w(TAG, "insertParts(" + attachments.size() + ")");

    for (Attachment attachment : attachments) {
      AttachmentId attachmentId = insertAttachment(masterSecret, mmsId, attachment);
      Log.w(TAG, "Inserted attachment at ID: " + attachmentId);
    }
  }

  public @NonNull Attachment updateAttachmentData(@NonNull MasterSecret masterSecret,
                                                  @NonNull Attachment attachment,
                                                  @NonNull MediaStream mediaStream)
      throws MmsException
  {
    SQLiteDatabase     database           = databaseHelper.getWritableDatabase();
    DatabaseAttachment databaseAttachment = (DatabaseAttachment) attachment;
    File               dataFile           = getAttachmentDataFile(databaseAttachment.getAttachmentId(), DATA);

    if (dataFile == null) {
      throw new MmsException("No attachment data found!");
    }

    long dataSize = setAttachmentData(masterSecret, dataFile, mediaStream.getStream());

    ContentValues contentValues = new ContentValues();
    contentValues.put(SIZE, dataSize);
    contentValues.put(CONTENT_TYPE, mediaStream.getMimeType());

    database.update(TABLE_NAME, contentValues, PART_ID_WHERE, databaseAttachment.getAttachmentId().toStrings());

    return new DatabaseAttachment(databaseAttachment.getAttachmentId(),
                                  databaseAttachment.getMmsId(),
                                  databaseAttachment.hasData(),
                                  databaseAttachment.hasThumbnail(),
                                  mediaStream.getMimeType(),
                                  databaseAttachment.getTransferState(),
                                  dataSize,
                                  databaseAttachment.getFileName(),
                                  databaseAttachment.getLocation(),
                                  databaseAttachment.getKey(),
                                  databaseAttachment.getRelay(),
                                  databaseAttachment.getDigest());
  }


  public void updateAttachmentFileName(@NonNull MasterSecret masterSecret,
                                       @NonNull AttachmentId attachmentId,
                                       @Nullable String fileName)
  {
    SQLiteDatabase database = databaseHelper.getWritableDatabase();

    if (fileName != null) {
      fileName = new MasterCipher(masterSecret).encryptBody(fileName);
    }

    ContentValues contentValues = new ContentValues(1);
    contentValues.put(FILE_NAME, fileName);

    database.update(TABLE_NAME, contentValues, PART_ID_WHERE, attachmentId.toStrings());
  }

  public void markAttachmentUploaded(long messageId, Attachment attachment) {
    ContentValues  values   = new ContentValues(1);
    SQLiteDatabase database = databaseHelper.getWritableDatabase();

    values.put(TRANSFER_STATE, TRANSFER_PROGRESS_DONE);
    database.update(TABLE_NAME, values, PART_ID_WHERE, ((DatabaseAttachment)attachment).getAttachmentId().toStrings());

    notifyConversationListeners(DatabaseFactory.getMmsDatabase(context).getThreadIdForMessage(messageId));
  }

  public void setTransferState(long messageId, @NonNull Attachment attachment, int transferState) {
    if (!(attachment instanceof DatabaseAttachment)) {
      throw new AssertionError("Attempt to update attachment that doesn't belong to DB!");
    }

    setTransferState(messageId, ((DatabaseAttachment) attachment).getAttachmentId(), transferState);
  }

  public void setTransferState(long messageId, @NonNull AttachmentId attachmentId, int transferState) {
    final ContentValues  values   = new ContentValues(1);
    final SQLiteDatabase database = databaseHelper.getWritableDatabase();

    values.put(TRANSFER_STATE, transferState);
    database.update(TABLE_NAME, values, PART_ID_WHERE, attachmentId.toStrings());
    notifyConversationListeners(DatabaseFactory.getMmsDatabase(context).getThreadIdForMessage(messageId));
    ApplicationContext.getInstance(context).notifyMediaControlEvent();
  }

  @VisibleForTesting
  protected @Nullable InputStream getDataStream(MasterSecret masterSecret, AttachmentId attachmentId, String dataType)
  {
    File dataFile = getAttachmentDataFile(attachmentId, dataType);

    try {
      if (dataFile != null) return DecryptingPartInputStream.createFor(masterSecret, dataFile);
      else                  return null;
    } catch (IOException e) {
      Log.w(TAG, e);
      return null;
    }
  }

  private @Nullable File getAttachmentDataFile(@NonNull AttachmentId attachmentId,
                                               @NonNull String dataType)
  {
    SQLiteDatabase database = databaseHelper.getReadableDatabase();
    Cursor         cursor   = null;

    try {
      cursor = database.query(TABLE_NAME, new String[]{dataType}, PART_ID_WHERE, attachmentId.toStrings(),
                              null, null, null);

      if (cursor != null && cursor.moveToFirst()) {
        if (cursor.isNull(0)) {
          return null;
        }

        return new File(cursor.getString(0));
      } else {
        return null;
      }
    } finally {
      if (cursor != null)
        cursor.close();
    }

  }

  private @NonNull Pair<File, Long> setAttachmentData(@NonNull MasterSecret masterSecret,
                                                      @NonNull Uri uri)
      throws MmsException
  {
    try {
      InputStream inputStream = PartAuthority.getAttachmentStream(context, masterSecret, uri);
      return setAttachmentData(masterSecret, inputStream);
    } catch (IOException e) {
      throw new MmsException(e);
    }
  }

  private @NonNull Pair<File, Long> setAttachmentData(@NonNull MasterSecret masterSecret,
                                                      @NonNull InputStream in)
      throws MmsException
  {
    try {
      File partsDirectory = context.getDir("parts", Context.MODE_PRIVATE);
      File dataFile       = File.createTempFile("part", ".mms", partsDirectory);

      return new Pair<>(dataFile, setAttachmentData(masterSecret, dataFile, in));
    } catch (IOException e) {
      throw new MmsException(e);
    }
  }

  private long setAttachmentData(@NonNull MasterSecret masterSecret,
                                 @NonNull File destination,
                                 @NonNull InputStream in)
      throws MmsException
  {
    try {
      OutputStream out = new EncryptingPartOutputStream(destination, masterSecret);
      return Util.copy(in, out);
    } catch (IOException e) {
      throw new MmsException(e);
    }
  }

  DatabaseAttachment getAttachment(@Nullable MasterSecret masterSecret, Cursor cursor) {
    String encryptedFileName = cursor.getString(cursor.getColumnIndexOrThrow(FILE_NAME));
    String fileName          = null;

    if (masterSecret != null && !TextUtils.isEmpty(encryptedFileName)) {
      try {
        fileName = new MasterCipher(masterSecret).decryptBody(encryptedFileName);
      } catch (InvalidMessageException e) {
        Log.w(TAG, e);
      }
    }

    return new DatabaseAttachment(new AttachmentId(cursor.getLong(cursor.getColumnIndexOrThrow(ATTACHMENT_ID_ALIAS)),
                                                   cursor.getLong(cursor.getColumnIndexOrThrow(UNIQUE_ID))),
                                  cursor.getLong(cursor.getColumnIndexOrThrow(MMS_ID)),
                                  !cursor.isNull(cursor.getColumnIndexOrThrow(DATA)),
                                  !cursor.isNull(cursor.getColumnIndexOrThrow(THUMBNAIL)),
                                  cursor.getString(cursor.getColumnIndexOrThrow(CONTENT_TYPE)),
                                  cursor.getInt(cursor.getColumnIndexOrThrow(TRANSFER_STATE)),
                                  cursor.getLong(cursor.getColumnIndexOrThrow(SIZE)),
                                  fileName,
                                  cursor.getString(cursor.getColumnIndexOrThrow(CONTENT_LOCATION)),
                                  cursor.getString(cursor.getColumnIndexOrThrow(CONTENT_DISPOSITION)),
                                  cursor.getString(cursor.getColumnIndexOrThrow(NAME)),
                                  cursor.getBlob(cursor.getColumnIndexOrThrow(DIGEST)));
  }


  private AttachmentId insertAttachment(MasterSecretUnion masterSecret, long mmsId, Attachment attachment)
      throws MmsException
  {
    Log.w(TAG, "Inserting attachment for mms id: " + mmsId);

    SQLiteDatabase   database = databaseHelper.getWritableDatabase();
    Pair<File, Long> partData = null;
    long             uniqueId = System.currentTimeMillis();
    String           fileName = null;

    if (masterSecret.getMasterSecret().isPresent() && attachment.getDataUri() != null) {
      partData = setAttachmentData(masterSecret.getMasterSecret().get(), attachment.getDataUri());
      Log.w(TAG, "Wrote part to file: " + partData.first.getAbsolutePath());
    }

    if (masterSecret.getMasterSecret().isPresent() && !TextUtils.isEmpty(attachment.getFileName())) {
      fileName = new MasterCipher(masterSecret.getMasterSecret().get()).encryptBody(attachment.getFileName());
    }

    ContentValues contentValues = new ContentValues();
    contentValues.put(MMS_ID, mmsId);
    contentValues.put(CONTENT_TYPE, attachment.getContentType());
    contentValues.put(TRANSFER_STATE, attachment.getTransferState());
    contentValues.put(UNIQUE_ID, uniqueId);
    contentValues.put(CONTENT_LOCATION, attachment.getLocation());
    contentValues.put(DIGEST, attachment.getDigest());
    contentValues.put(CONTENT_DISPOSITION, attachment.getKey());
    contentValues.put(NAME, attachment.getRelay());
    contentValues.put(FILE_NAME, fileName);
    contentValues.put(SIZE, attachment.getSize());

    if (partData != null) {
      contentValues.put(DATA, partData.first.getAbsolutePath());
      contentValues.put(SIZE, partData.second);
    }

    long         rowId        = database.insert(TABLE_NAME, null, contentValues);
    AttachmentId attachmentId = new AttachmentId(rowId, uniqueId);

    if (partData != null) {
      Log.w(TAG, "Submitting thumbnail generation job...");
      thumbnailExecutor.submit(new ThumbnailFetchCallable(masterSecret.getMasterSecret().get(), attachmentId));
    }

    return attachmentId;
  }


  @VisibleForTesting
  protected void updateAttachmentThumbnail(MasterSecret masterSecret, AttachmentId attachmentId, InputStream in, float aspectRatio)
      throws MmsException
  {
    Log.w(TAG, "updating part thumbnail for #" + attachmentId);

    Pair<File, Long> thumbnailFile = setAttachmentData(masterSecret, in);

    SQLiteDatabase database = databaseHelper.getWritableDatabase();
    ContentValues  values   = new ContentValues(2);

    values.put(THUMBNAIL, thumbnailFile.first.getAbsolutePath());
    values.put(THUMBNAIL_ASPECT_RATIO, aspectRatio);

    database.update(TABLE_NAME, values, PART_ID_WHERE, attachmentId.toStrings());

    Cursor cursor = database.query(TABLE_NAME, new String[] {MMS_ID}, PART_ID_WHERE, attachmentId.toStrings(), null, null, null);

    try {
      if (cursor != null && cursor.moveToFirst()) {
        notifyConversationListeners(DatabaseFactory.getMmsDatabase(context).getThreadIdForMessage(cursor.getLong(cursor.getColumnIndexOrThrow(MMS_ID))));
      }
    } finally {
      if (cursor != null) cursor.close();
    }
  }


  @VisibleForTesting
  class ThumbnailFetchCallable implements Callable<InputStream> {

    private final MasterSecret masterSecret;
    private final AttachmentId attachmentId;

    ThumbnailFetchCallable(MasterSecret masterSecret, AttachmentId attachmentId) {
      this.masterSecret = masterSecret;
      this.attachmentId = attachmentId;
    }

    @Override
    public @Nullable InputStream call() throws Exception {
      Log.w(TAG, "Executing thumbnail job...");
      final InputStream stream = getDataStream(masterSecret, attachmentId, THUMBNAIL);

      if (stream != null) {
        return stream;
      }

      DatabaseAttachment attachment = getAttachment(masterSecret, attachmentId);

      if (attachment == null || !attachment.hasData()) {
        return null;
      }

      ThumbnailData data;

      if (ContentType.isVideoType(attachment.getContentType())) {
        data = generateVideoThumbnail(masterSecret, attachmentId);
      } else{
        data = MediaUtil.generateThumbnail(context, masterSecret, attachment.getContentType(), attachment.getDataUri());
      }

      if (data == null) {
        return null;
      }

      updateAttachmentThumbnail(masterSecret, attachmentId, data.toDataStream(), data.getAspectRatio());

      return getDataStream(masterSecret, attachmentId, THUMBNAIL);
    }

    private ThumbnailData generateVideoThumbnail(MasterSecret masterSecret, AttachmentId attachmentId) {
      if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
        Log.w(TAG, "Video thumbnails not supported...");
        return null;
      }

      File mediaFile = getAttachmentDataFile(attachmentId, DATA);

      if (mediaFile == null) {
        Log.w(TAG, "No data file found for video thumbnail...");
        return null;
      }

      EncryptedMediaDataSource dataSource = new EncryptedMediaDataSource(masterSecret, mediaFile);
      MediaMetadataRetriever   retriever  = new MediaMetadataRetriever();
      retriever.setDataSource(dataSource);

      Bitmap bitmap = retriever.getFrameAtTime(1000);

      Log.w(TAG, "Generated video thumbnail...");
      return new ThumbnailData(bitmap);
    }
  }
}