public class MainActivity extends AppCompatActivity {

static final int REQUEST_ACCOUNT_PICKER = 1000;
static final int REQUEST_AUTHORIZATION = 1001;
static final int REQUEST_GOOGLE_PLAY_SERVICES = 1002;
private static final String[] SCOPES = {CalendarScopes.CALENDAR_READONLY, CalendarScopes.CALENDAR};
private static final String PREF_ACCOUNT_NAME = "accountName";
GoogleAccountCredential mCredential;
ProgressDialog mProgress;
TextView tv;
private String myaccountName;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    SharedPreferences settings = getPreferences(Context.MODE_PRIVATE);
    ///////////////////////////////c2 Manages Intent from SignIn/////////////////
    Intent inn = getIntent();
    Bundle extras = inn.getExtras();
    if (extras != null) {
        // Intent inn=getIntent();
        myaccountName = extras.getString("accountName");
        SharedPreferences.Editor editor = settings.edit();
        editor.putString(PREF_ACCOUNT_NAME, myaccountName);
        editor.apply();
    }

    tv = (TextView) findViewById(R.id.result1);
    if (myaccountName != null) {
        mCredential = GoogleAccountCredential.usingOAuth2(
                getApplicationContext(), Arrays.asList(SCOPES))
                .setBackOff(new ExponentialBackOff())
                .setSelectedAccountName(settings.getString(PREF_ACCOUNT_NAME, null));
    }

    tv.setVerticalScrollBarEnabled(true);
    tv.setMovementMethod(new ScrollingMovementMethod());
    mProgress = new ProgressDialog(this);
    mProgress.setMessage("Getting Your Data Champ :-) ");

    //////////////// CODE NEW///////////////////
    mService = new com.google.api.services.calendar.Calendar.Builder(
            transport, jsonFactory, mCredential)
            .setApplicationName("MeetingPlanner")
            .build();
    btnEvent = (Button) findViewById(R.id.evt_button);
    btnEvent.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
            Log.d("Meeting Planner: ",mService.toString());
            new CreateEventTask(mService).execute();
        }
    });
    ///////////////////////////////////

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    switch (requestCode) {
        case REQUEST_GOOGLE_PLAY_SERVICES:
            if (resultCode != RESULT_OK) {
                isGooglePlayServicesAvailable();
            }
            break;
        case REQUEST_ACCOUNT_PICKER:
            if (resultCode == RESULT_CANCELED) {
                tv.setText("Account unspecified.");
            }
    }
    super.onActivityResult(requestCode, resultCode, data);
}

@Override
protected void onResume() {
    super.onResume();
    if (isGooglePlayServicesAvailable()) {
        refreshResults();
    } else {
        tv.setText("Google Play Services required: " +
                "after installing, close and relaunch this app.");
    }
}

private void refreshResults() {
    if (isDeviceOnline()) {
        new MakeRequestTask(mCredential).execute();
    } else {
        tv.setText("No network connection available.");
    }
}

private boolean isDeviceOnline() {
    ConnectivityManager connMgr =
            (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
    return (networkInfo != null && networkInfo.isConnected());
}

private boolean isGooglePlayServicesAvailable() {
    final int connectionStatusCode =
            GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
    if (GooglePlayServicesUtil.isUserRecoverableError(connectionStatusCode)) {
        showGooglePlayServicesAvailabilityErrorDialog(connectionStatusCode);
        return false;
    } else if (connectionStatusCode != ConnectionResult.SUCCESS) {
        return false;
    }
    return true;
}

void showGooglePlayServicesAvailabilityErrorDialog(
        final int connectionStatusCode) {
    Dialog dialog = GooglePlayServicesUtil.getErrorDialog(
            connectionStatusCode,
            MainActivity.this,
            REQUEST_GOOGLE_PLAY_SERVICES);
    dialog.show();
}

private class MakeRequestTask extends AsyncTask<Void, Void, List<String>> {
    private com.google.api.services.calendar.Calendar mService = null;
    private Exception mLastError = null;

    public MakeRequestTask(GoogleAccountCredential credential) {
        HttpTransport transport = AndroidHttp.newCompatibleTransport();
        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
        mService = new com.google.api.services.calendar.Calendar.Builder(
                transport, jsonFactory, credential)
                //.setApplicationName("Google Calendar API Android Quickstart")
                .build();
    }

    /**
     * Background task to call Google Calendar API.
     *
     * @param params no parameters needed for this task.
     */
    @Override
    protected List<String> doInBackground(Void... params) {
        try {
            return getDataFromApi();
        } catch (Exception e) {
            mLastError = e;
            cancel(true);
            return null;
        }
    }

    /**
     * Fetch a list of the next 10 events from the primary calendar.
     *
     * @return List of Strings describing returned events.
     * @throws IOException
     */
    private List<String> getDataFromApi() throws IOException, ParseException {
        // List the next 10 events from the primary calendar.
        DateTime now = new DateTime(System.currentTimeMillis());
        List<String> eventStrings = new ArrayList<String>();
        Events events = mService.events().list("primary")
                .setMaxResults(30)
                .setTimeMin(now)
                .setOrderBy("startTime")
                .setSingleEvents(true)
                .execute();
        List<Event> items = events.getItems();

        for (Event event : items) {
            DateTime start = event.getStart().getDateTime();
            if (start == null) {
                // All-day events don't have start times, so just use
                // the start date.
                start = event.getStart().getDate();
            }
            DateTime end = event.getEnd().getDateTime();

            String eventTitle = event.getSummary();

            String StartDB = String.valueOf(start);
            String EndDB = String.valueOf(end);

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");

            Calendar cal = Calendar.getInstance();
            cal.setTime(sdf.parse(StartDB));

            SimpleDateFormat[] dateFormat= new SimpleDateFormat[2];
            dateFormat[0] = new SimpleDateFormat("yyyy-MM-dd");
            dateFormat[1] = new SimpleDateFormat("HH:mm:ss");

            String Start_Date= dateFormat[0].format(cal.getTime());
            String Start_Time= dateFormat[1].format(cal.getTime());

            Calendar cal1 = Calendar.getInstance();
            cal1.setTime(sdf.parse(EndDB));

            String End_Date= dateFormat[0].format(cal1.getTime());
            String End_Time= dateFormat[1].format(cal1.getTime());

            String Location = event.getLocation();

            String Creator = String.valueOf(event.getCreator());
            Creator = Creator.replace(""", ""); //Removes all the Quotes from the string displayName:Qamran Rajput,email:qami1502@gmail.com,self:true}

            StringTokenizer tokens = new StringTokenizer(Creator, ":");
            tokens.nextToken();
            String first = tokens.nextToken();// this will contain Qamran Rajput,email
            String second = tokens.nextToken();/////////////////qami1502@gmail.com,self
            StringTokenizer tokens1 = new StringTokenizer(first, ",");
            String creatorName = tokens1.nextToken();// this will contain Qamran Rajput
            StringTokenizer tokens2 = new StringTokenizer(second, ",");
            String creatorEmail = tokens2.nextToken();/////////////////qami1502@gmail.com

            String mFlag= "0";

            new Datasync().execute(eventTitle, Start_Date, End_Date, Start_Time, End_Time, creatorEmail, mFlag, Location);
            // TODO
            Log.d("Title :", eventTitle);
            Log.d("Name :", creatorName);
            Log.d("Start Date :", Start_Date);
            Log.d("End Date :", End_Date );
            Log.d("Start Time :", Start_Time );
            Log.d("End Time :", End_Time );
            Log.d("Email :", creatorEmail);
            Log.d("Location :", Location );

            eventStrings.add(
                    String.format("%s (%s)", event.getSummary(), start));
        }
        return eventStrings;
    }


    @Override
    protected void onPreExecute() {
        tv.setText("");
        mProgress.show();
    }

    @Override
    protected void onPostExecute(List<String> output) {
        mProgress.hide();
        if (output == null || output.size() == 0) {
            tv.setText("No results returned.");
        } else {
            output.add(0, "Data retrieved using the Google Calendar API:");
            tv.setText(TextUtils.join("n", output));
        }
    }

    @Override
    protected void onCancelled() {
        mProgress.hide();
        if (mLastError != null) {
            if (mLastError instanceof GooglePlayServicesAvailabilityIOException) {
                showGooglePlayServicesAvailabilityErrorDialog(
                        ((GooglePlayServicesAvailabilityIOException) mLastError)
                                .getConnectionStatusCode());
            } else if (mLastError instanceof UserRecoverableAuthIOException) {
                startActivityForResult(
                        ((UserRecoverableAuthIOException) mLastError).getIntent(),
                        MainActivity.REQUEST_AUTHORIZATION);
            } else {
                tv.setText("The following error occurred:n"
                        + mLastError.getMessage());
            }
        } else {
            tv.setText("Request cancelled.");
        }
    }
}
}