arcanechat-android/src/main/java/org/thoughtcrime/securesms/ResolveMediaTask.java

package org.thoughtcrime.securesms;

import static org.thoughtcrime.securesms.util.MediaUtil.getMimeType;

import android.app.Activity;
import android.database.Cursor;
import android.net.Uri;
import android.os.AsyncTask;
import android.provider.OpenableColumns;
import android.util.Log;
import de.cketti.safecontentresolver.SafeContentResolver;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.util.HashSet;
import org.thoughtcrime.securesms.providers.PersistentBlobProvider;

public class ResolveMediaTask extends AsyncTask<Uri, Void, Uri> {

  private static final String TAG = "ResolveMediaTask";

  interface OnMediaResolvedListener {
    void onMediaResolved(Uri uri);
  }

  private final WeakReference<Activity> contextRef;
  private final WeakReference<OnMediaResolvedListener> listenerWeakReference;

  private static final HashSet<ResolveMediaTask> instances = new HashSet<>();

  ResolveMediaTask(Activity activityContext, ResolveMediaTask.OnMediaResolvedListener listener) {
    this.contextRef = new WeakReference<>(activityContext);
    this.listenerWeakReference = new WeakReference<>(listener);
    instances.add(this);
  }

  @Override
  protected Uri doInBackground(Uri... uris) {
    try {
      Uri uri = uris[0];
      if (uris.length != 1 || uri == null) {
        return null;
      }

      InputStream inputStream;
      String fileName = null;
      Long fileSize = null;

      SafeContentResolver safeContentResolver = SafeContentResolver.newInstance(contextRef.get());
      inputStream = safeContentResolver.openInputStream(uri);

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

      Cursor cursor =
          contextRef
              .get()
              .getContentResolver()
              .query(
                  uri,
                  new String[] {OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE},
                  null,
                  null,
                  null);

      try {
        if (cursor != null && cursor.moveToFirst()) {
          try {
            fileName = cursor.getString(cursor.getColumnIndexOrThrow(OpenableColumns.DISPLAY_NAME));
            fileSize = cursor.getLong(cursor.getColumnIndexOrThrow(OpenableColumns.SIZE));
          } catch (IllegalArgumentException e) {
            Log.w(TAG, e);
          }
        }
      } finally {
        if (cursor != null) cursor.close();
      }

      if (fileName == null) {
        fileName = uri.getLastPathSegment();
      }

      String mimeType = getMimeType(contextRef.get(), uri);
      return PersistentBlobProvider.getInstance()
          .create(contextRef.get(), inputStream, mimeType, fileName, fileSize);
    } catch (NullPointerException | FileNotFoundException ioe) {
      Log.w(TAG, ioe);
      return null;
    }
  }

  @Override
  protected void onPostExecute(Uri uri) {
    instances.remove(this);
    if (!this.isCancelled()) {
      listenerWeakReference.get().onMediaResolved(uri);
    }
  }

  @Override
  protected void onCancelled() {
    instances.remove(this);
    super.onCancelled();
    listenerWeakReference.get().onMediaResolved(null);
  }

  public static boolean isExecuting() {
    return !instances.isEmpty();
  }

  public static void cancelTasks() {
    for (ResolveMediaTask task : instances) {
      task.cancel(true);
    }
  }

  private boolean hasFileScheme(Uri uri) {
    if (uri == null) {
      return false;
    }
    return "file".equals(uri.getScheme());
  }
}