content: /*
   * Copyright (C) 2013 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.example.android.bluetoothlegatt;
  
  import android.app.Service;
  import android.bluetooth.BluetoothAdapter;
  import android.bluetooth.BluetoothDevice;
  import android.bluetooth.BluetoothGatt;
  import android.bluetooth.BluetoothGattCallback;
  import android.bluetooth.BluetoothGattCharacteristic;
  import android.bluetooth.BluetoothGattDescriptor;
  import android.bluetooth.BluetoothGattService;
  import android.bluetooth.BluetoothManager;
  import android.bluetooth.BluetoothProfile;
  import android.content.Context;
  import android.content.Intent;
  import android.os.Binder;
  import android.os.IBinder;
  import android.util.Log;
  
  import java.util.List;
  import java.util.UUID;
  
  /**
   * Service for managing connection and data communication with a GATT server hosted on a
   * given Bluetooth LE device.
   */
  public class BluetoothLeService extends Service {
      private final static String TAG = BluetoothLeService.class.getSimpleName();
  
      private BluetoothManager mBluetoothManager;
      private BluetoothAdapter mBluetoothAdapter;
      private String mBluetoothDeviceAddress;
      private BluetoothGatt mBluetoothGatt;
      private int mConnectionState = STATE_DISCONNECTED;
  
      private static final int STATE_DISCONNECTED = 0;
      private static final int STATE_CONNECTING = 1;
      private static final int STATE_CONNECTED = 2;
  
      public final static String ACTION_GATT_CONNECTED =
              "com.example.bluetooth.le.ACTION_GATT_CONNECTED";
      public final static String ACTION_GATT_DISCONNECTED =
              "com.example.bluetooth.le.ACTION_GATT_DISCONNECTED";
      public final static String ACTION_GATT_SERVICES_DISCOVERED =
              "com.example.bluetooth.le.ACTION_GATT_SERVICES_DISCOVERED";
      public final static String ACTION_DATA_AVAILABLE =
              "com.example.bluetooth.le.ACTION_DATA_AVAILABLE";
      public final static String EXTRA_DATA =
              "com.example.bluetooth.le.EXTRA_DATA";
  
      public final static UUID UUID_HEART_RATE_MEASUREMENT =
              UUID.fromString(SampleGattAttributes.HEART_RATE_MEASUREMENT);
  
      // Implements callback methods for GATT events that the app cares about.  For example,
      // connection change and services discovered.
      private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
          @Override
          public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
              String intentAction;
              if (newState == BluetoothProfile.STATE_CONNECTED) {
                  intentAction = ACTION_GATT_CONNECTED;
                  mConnectionState = STATE_CONNECTED;
                  broadcastUpdate(intentAction);
                  Log.i(TAG, "Connected to GATT server.");
                  // Attempts to discover services after successful connection.
                  Log.i(TAG, "Attempting to start service discovery:" +
                          mBluetoothGatt.discoverServices());
  
              } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
                  intentAction = ACTION_GATT_DISCONNECTED;
                  mConnectionState = STATE_DISCONNECTED;
                  Log.i(TAG, "Disconnected from GATT server.");
                  broadcastUpdate(intentAction);
              }
          }
  
          @Override
          public void onServicesDiscovered(BluetoothGatt gatt, int status) {
              if (status == BluetoothGatt.GATT_SUCCESS) {
                  broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
              } else {
                  Log.w(TAG, "onServicesDiscovered received: " + status);
              }
          }
  
          @Override
          public void onCharacteristicRead(BluetoothGatt gatt,
                                           BluetoothGattCharacteristic characteristic,
                                           int status) {
              if (status == BluetoothGatt.GATT_SUCCESS) {
                  broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
              }
          }
  
          @Override
          public void onCharacteristicChanged(BluetoothGatt gatt,
                                              BluetoothGattCharacteristic characteristic) {
              broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
          }
      };
  
      private void broadcastUpdate(final String action) {
          final Intent intent = new Intent(action);
          sendBroadcast(intent);
      }
  
      private void broadcastUpdate(final String action,
                                   final BluetoothGattCharacteristic characteristic) {
          final Intent intent = new Intent(action);
  
          // This is special handling for the Heart Rate Measurement profile.  Data parsing is
          // carried out as per profile specifications:
          // http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
          if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
              int flag = characteristic.getProperties();
              int format = -1;
              if ((flag & 0x01) != 0) {
                  format = BluetoothGattCharacteristic.FORMAT_UINT16;
                  Log.d(TAG, "Heart rate format UINT16.");
              } else {
                  format = BluetoothGattCharacteristic.FORMAT_UINT8;
                  Log.d(TAG, "Heart rate format UINT8.");
              }
              final int heartRate = characteristic.getIntValue(format, 1);
              Log.d(TAG, String.format("Received heart rate: %d", heartRate));
              intent.putExtra(EXTRA_DATA, String.valueOf(heartRate));
          } else {
              // For all other profiles, writes the data formatted in HEX.
              final byte[] data = characteristic.getValue();
              if (data != null && data.length > 0) {
                  final StringBuilder stringBuilder = new StringBuilder(data.length);
                  for(byte byteChar : data)
                      stringBuilder.append(String.format("%02X ", byteChar));
                  intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
              }
          }
          sendBroadcast(intent);
      }
  
      public class LocalBinder extends Binder {
          BluetoothLeService getService() {
              return BluetoothLeService.this;
          }
      }
  
      @Override
      public IBinder onBind(Intent intent) {
          return mBinder;
      }
  
      @Override
      public boolean onUnbind(Intent intent) {
          // After using a given device, you should make sure that BluetoothGatt.close() is called
          // such that resources are cleaned up properly.  In this particular example, close() is
          // invoked when the UI is disconnected from the Service.
          close();
          return super.onUnbind(intent);
      }
  
      private final IBinder mBinder = new LocalBinder();
  
      /**
       * Initializes a reference to the local Bluetooth adapter.
       *
       * @return Return true if the initialization is successful.
       */
      public boolean initialize() {
          // For API level 18 and above, get a reference to BluetoothAdapter through
          // BluetoothManager.
          if (mBluetoothManager == null) {
              mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
              if (mBluetoothManager == null) {
                  Log.e(TAG, "Unable to initialize BluetoothManager.");
                  return false;
              }
          }
  
          mBluetoothAdapter = mBluetoothManager.getAdapter();
          if (mBluetoothAdapter == null) {
              Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
              return false;
          }
  
          return true;
      }
  
      /**
       * Connects to the GATT server hosted on the Bluetooth LE device.
       *
       * @param address The device address of the destination device.
       *
       * @return Return true if the connection is initiated successfully. The connection result
       *         is reported asynchronously through the
       *         {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
       *         callback.
       */
      public boolean connect(final String address) {
          if (mBluetoothAdapter == null || address == null) {
              Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
              return false;
          }
  
          // Previously connected device.  Try to reconnect.
          if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress)
                  && mBluetoothGatt != null) {
              Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
              if (mBluetoothGatt.connect()) {
                  mConnectionState = STATE_CONNECTING;
                  return true;
              } else {
                  return false;
              }
          }
  
          final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
          if (device == null) {
              Log.w(TAG, "Device not found.  Unable to connect.");
              return false;
          }
          // We want to directly connect to the device, so we are setting the autoConnect
          // parameter to false.
          mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
          Log.d(TAG, "Trying to create a new connection.");
          mBluetoothDeviceAddress = address;
          mConnectionState = STATE_CONNECTING;
          return true;
      }
  
      /**
       * Disconnects an existing connection or cancel a pending connection. The disconnection result
       * is reported asynchronously through the
       * {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
       * callback.
       */
      public void disconnect() {
          if (mBluetoothAdapter == null || mBluetoothGatt == null) {
              Log.w(TAG, "BluetoothAdapter not initialized");
              return;
          }
          mBluetoothGatt.disconnect();
      }
  
      /**
       * After using a given BLE device, the app must call this method to ensure resources are
       * released properly.
       */
      public void close() {
          if (mBluetoothGatt == null) {
              return;
          }
          mBluetoothGatt.close();
          mBluetoothGatt = null;
      }
  
      /**
       * Request a read on a given {@code BluetoothGattCharacteristic}. The read result is reported
       * asynchronously through the {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
       * callback.
       *
       * @param characteristic The characteristic to read from.
       */
      public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
          if (mBluetoothAdapter == null || mBluetoothGatt == null) {
              Log.w(TAG, "BluetoothAdapter not initialized");
              return;
          }
          mBluetoothGatt.readCharacteristic(characteristic);
      }
  
      /**
       * Enables or disables notification on a give characteristic.
       *
       * @param characteristic Characteristic to act on.
       * @param enabled If true, enable notification.  False otherwise.
       */
      public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,
                                                boolean enabled) {
          if (mBluetoothAdapter == null || mBluetoothGatt == null) {
              Log.w(TAG, "BluetoothAdapter not initialized");
              return;
          }
          mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
  
          // This is specific to Heart Rate Measurement.
          if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
              BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
                      UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
              descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
              mBluetoothGatt.writeDescriptor(descriptor);
          }
      }
  
      /**
       * Retrieves a list of supported GATT services on the connected device. This should be
       * invoked only after {@code BluetoothGatt#discoverServices()} completes successfully.
       *
       * @return A {@code List} of supported services.
       */
      public List<BluetoothGattService> getSupportedGattServices() {
          if (mBluetoothGatt == null) return null;
  
          return mBluetoothGatt.getServices();
      }
  }
  