package com.mapbox.mapboxsdk.telemetry;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.ServiceInfo;
import android.os.AsyncTask;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.util.Log;

/**
 * Manages Startup and Shutdown of Telemetry resources
 */
public class TelemetryService extends Service {

    private static final String TAG = "TelemetryService";

    private TelemetryLocationReceiver telemetryLocationReceiver = null;

    /**
     * Return the communication channel to the service.  May return null if
     * clients can not bind to the service.  The returned
     * {@link IBinder} is usually for a complex interface
     * that has been <a href="{@docRoot}guide/components/aidl.html">described using
     * aidl</a>.
     *
     * <p><em>Note that unlike other application components, calls on to the
     * IBinder interface returned here may not happen on the main thread
     * of the process</em>.  More information about the main thread can be found in
     * <a href="{@docRoot}guide/topics/fundamentals/processes-and-threads.html">Processes and
     * Threads</a>.</p>
     *
     * @param intent The Intent that was used to bind to this service,
     *               as given to {@link Context#bindService
     *               Context.bindService}.  Note that any extras that were included with
     *               the Intent at that point will <em>not</em> be seen here.
     * @return Return an IBinder through which clients can call on to the
     * service.
     */
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }


    /**
     * Called by the system when the service is first created.  Do not call this method directly.
     */
    @Override
    public void onCreate() {
        super.onCreate();

        Log.i(TAG, "onCreate() called");

        // Enable Location Listening for lifecycle of app
        IntentFilter filter = new IntentFilter(TelemetryLocationReceiver.INTENT_STRING);
        telemetryLocationReceiver = new TelemetryLocationReceiver();
        registerReceiver(telemetryLocationReceiver, filter);
    }

    /**
     * Called by the system to notify a Service that it is no longer used and is being removed.  The
     * service should clean up any resources it holds (threads, registered
     * receivers, etc) at this point.  Upon return, there will be no more calls
     * in to this Service object and it is effectively dead.  Do not call this method directly.
     */
    @Override
    public void onDestroy() {
        shutdownTelemetry();
        super.onDestroy();
    }

    /**
     * This is called if the service is currently running and the user has
     * removed a task that comes from the service's application.  If you have
     * set {@link ServiceInfo#FLAG_STOP_WITH_TASK ServiceInfo.FLAG_STOP_WITH_TASK}
     * then you will not receive this callback; instead, the service will simply
     * be stopped.
     *
     * @param rootIntent The original root Intent that was used to launch
     *                   the task that is being removed.
     */
    @Override
    public void onTaskRemoved(Intent rootIntent) {
        shutdownTelemetry();
        super.onTaskRemoved(rootIntent);
    }

    /**
     * Called by the system every time a client explicitly starts the service by calling
     * {@link Context#startService}, providing the arguments it supplied and a
     * unique integer token representing the start request.  Do not call this method directly.
     *
     * <p>For backwards compatibility, the default implementation calls
     * {@link #onStart} and returns either {@link #START_STICKY}
     * or {@link #START_STICKY_COMPATIBILITY}.
     * </p>
     * <p>If you need your application to run on platform versions prior to API
     * level 5, you can use the following model to handle the older {@link #onStart}
     * callback in that case.  The <code>handleCommand</code> method is implemented by
     * you as appropriate:
     * </p>
     *
     * <p class="caution">Note that the system calls this on your
     * service's main thread.  A service's main thread is the same
     * thread where UI operations take place for Activities running in the
     * same process.  You should always avoid stalling the main
     * thread's event loop.  When doing long-running operations,
     * network calls, or heavy disk I/O, you should kick off a new
     * thread, or use {@link AsyncTask}.</p>
     *
     * @param intent  The Intent supplied to {@link Context#startService},
     *                as given.  This may be null if the service is being restarted after
     *                its process has gone away, and it had previously returned anything
     *                except {@link #START_STICKY_COMPATIBILITY}.
     * @param flags   Additional data about this start request.  Currently either
     *                0, {@link #START_FLAG_REDELIVERY}, or {@link #START_FLAG_RETRY}.
     * @param startId A unique integer representing this specific request to
     *                start.  Use with {@link #stopSelfResult(int)}.
     * @return The return value indicates what semantics the system should
     * use for the service's current started state.  It may be one of the
     * constants associated with the {@link #START_CONTINUATION_MASK} bits.
     * @see #stopSelfResult(int)
     */
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        Log.i(TAG, "onStartCommand() called");

        return START_NOT_STICKY;
    }

    private void shutdownTelemetry() {

        // Send Any Remaining events to the server
        MapboxEventManager.getMapboxEventManager().flushEventsQueueImmediately();

        // Undesired, but needed trick to keep app alive long enough for data to get to server
        try {
            Thread.sleep(1000);
        } catch (Exception e) {
            Log.e(TAG, "Error while trying to sleep for 1 second: " + e);
        }

        try {
            unregisterReceiver(telemetryLocationReceiver);
        } catch (IllegalArgumentException e) {
            Log.e(TAG, "Error when unregisterReceiver: " + e);
        }

    }
}