WearDispatcher.java

package com.segment.analytics;

import static android.os.Process.THREAD_PRIORITY_BACKGROUND;

import android.content.Context;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.wearable.MessageApi;
import com.google.android.gms.wearable.Node;
import com.google.android.gms.wearable.NodeApi;
import com.google.android.gms.wearable.Wearable;
import com.segment.analytics.internal.Utils;
import java.util.Collection;
import java.util.HashSet;

class WearDispatcher {

  private static final String DISPATCHER_THREAD_NAME = Utils.THREAD_PREFIX + "Wear-Dispatcher";

  final Handler handler;
  final HandlerThread dispatcherThread;
  final GoogleApiClient googleApiClient;
  final Cartographer cartographer;

  WearDispatcher(Context context) {
    googleApiClient = new GoogleApiClient.Builder(context).addApi(Wearable.API).build();
    cartographer = Cartographer.INSTANCE;
    dispatcherThread = new HandlerThread(DISPATCHER_THREAD_NAME, THREAD_PRIORITY_BACKGROUND);
    dispatcherThread.start();
    handler = new DispatcherHandler(dispatcherThread.getLooper(), this);
  }

  void dispatchPayload(WearPayload payload) {
    handler.sendMessage(handler.obtainMessage(DispatcherHandler.REQUEST_DISPATCH, payload));
  }

  void performDispatch(WearPayload payload) {
    googleApiClient.blockingConnect();

    for (String node : getNodes(googleApiClient)) {
      MessageApi.SendMessageResult result =
          Wearable.MessageApi.sendMessage(
                  googleApiClient,
                  node,
                  WearAnalytics.ANALYTICS_PATH,
                  cartographer.toJson(payload).getBytes())
              .await();
      if (!result.getStatus().isSuccess()) {
        // todo: log error
      }
    }
  }

  private Collection<String> getNodes(GoogleApiClient googleApiClient) {
    HashSet<String> results = new HashSet<>();
    NodeApi.GetConnectedNodesResult nodes =
        Wearable.NodeApi.getConnectedNodes(googleApiClient).await();
    for (Node node : nodes.getNodes()) {
      results.add(node.getId());
    }
    return results;
  }

  private static class DispatcherHandler extends Handler {

    static final int REQUEST_DISPATCH = 0;
    private final WearDispatcher wearDispatcher;

    public DispatcherHandler(Looper looper, WearDispatcher wearDispatcher) {
      super(looper);
      this.wearDispatcher = wearDispatcher;
    }

    @Override
    public void handleMessage(final Message msg) {
      switch (msg.what) {
        case REQUEST_DISPATCH:
          WearPayload payload = (WearPayload) msg.obj;
          wearDispatcher.performDispatch(payload);
          break;
        default:
          Analytics.HANDLER.post(
              new Runnable() {
                @Override
                public void run() {
                  throw new AssertionError("Unhandled dispatcher message." + msg.what);
                }
              });
      }
    }
  }
}