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 uk.co.alt236.btlescan.services;
  
  import android.annotation.SuppressLint;
  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.BluetoothGattService;
  import android.bluetooth.BluetoothManager;
  import android.bluetooth.BluetoothProfile;
  import android.content.Context;
  import android.content.Intent;
  import android.os.IBinder;
  import android.util.Log;
  
  import java.util.List;
  
  /**
   * Service for managing connection and data communication with a GATT server hosted on a
   * given Bluetooth LE device.
   */
  public class BluetoothLeService extends Service {
      public final static String ACTION_GATT_CONNECTED = BluetoothLeService.class.getName() + ".ACTION_GATT_CONNECTED";
      public final static String ACTION_GATT_CONNECTING = BluetoothLeService.class.getName() + ".ACTION_GATT_CONNECTING";
      public final static String ACTION_GATT_DISCONNECTED = BluetoothLeService.class.getName() + ".ACTION_GATT_DISCONNECTED";
      public final static String ACTION_GATT_SERVICES_DISCOVERED = BluetoothLeService.class.getName() + ".ACTION_GATT_SERVICES_DISCOVERED";
      public final static String ACTION_DATA_AVAILABLE = BluetoothLeService.class.getName() + ".ACTION_DATA_AVAILABLE";
      public final static String EXTRA_DATA_RAW = BluetoothLeService.class.getName() + ".EXTRA_DATA_RAW";
      public final static String EXTRA_UUID_CHAR = BluetoothLeService.class.getName() + ".EXTRA_UUID_CHAR";
  
      private final static String TAG = BluetoothLeService.class.getSimpleName();
      private final IBinder mBinder = new LocalBinder(this);
      private BluetoothManager mBluetoothManager;
      private BluetoothAdapter mBluetoothAdapter;
      private String mBluetoothDeviceAddress;
      private BluetoothGatt mBluetoothGatt;
      private State mConnectionState = State.DISCONNECTED;
  
      // 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 onCharacteristicChanged(final BluetoothGatt gatt, final BluetoothGattCharacteristic characteristic) {
              broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
          }
  
          @Override
          public void onCharacteristicRead(final BluetoothGatt gatt,
                                           final BluetoothGattCharacteristic characteristic,
                                           final int status) {
  
              if (status == BluetoothGatt.GATT_SUCCESS) {
                  broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
              }
          }
  
          @SuppressLint("MissingPermission") // We check before this is called
          @Override
          public void onConnectionStateChange(final BluetoothGatt gatt,
                                              final int status,
                                              final int newState) {
  
              Log.d(TAG, "onConnectionStateChange: status=" + status + ", newState=" + newState);
  
              if (newState == BluetoothProfile.STATE_CONNECTED) {
                  setConnectionState(State.CONNECTED, true);
                  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) {
                  // Make sure we tidy up. On certain devices reusing a Gatt after a disconnection
                  // can cause problems.
                  disconnect();
  
                  setConnectionState(State.DISCONNECTED, true);
                  Log.i(TAG, "Disconnected from GATT server.");
              }
          }
  
          @Override
          public void onServicesDiscovered(final BluetoothGatt gatt, final int status) {
              if (status == BluetoothGatt.GATT_SUCCESS) {
                  broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
              } else {
                  Log.w(TAG, "onServicesDiscovered received: " + status);
              }
          }
      };
  
      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);
          intent.putExtra(EXTRA_UUID_CHAR, characteristic.getUuid().toString());
  
          // Always try to add the RAW value
          final byte[] data = characteristic.getValue();
          if (data != null && data.length > 0) {
              intent.putExtra(EXTRA_DATA_RAW, data);
          }
  
          sendBroadcast(intent);
      }
  
      /**
       * After using a given BLE device, the app must call this method to ensure resources are
       * released properly.
       */
      @SuppressLint("MissingPermission") // We check before this is called
      public void close() {
          if (mBluetoothGatt == null) {
              return;
          }
          mBluetoothGatt.close();
          mBluetoothGatt = null;
      }
  
      /**
       * 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.
       */
      @SuppressLint("MissingPermission") // We check before this is called
      public boolean connect(final String address) {
  
          final boolean retVal;
          if (mBluetoothAdapter == null || address == null) {
              Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
              retVal = false;
  
              // Previously connected device.  Try to reconnect.
          } else if (mBluetoothDeviceAddress != null
                  && address.equals(mBluetoothDeviceAddress)
                  && mBluetoothGatt != null) {
  
              Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
              if (mBluetoothGatt.connect()) {
                  Log.d(TAG, "Connection attempt OK.");
                  setConnectionState(State.CONNECTING, true);
                  retVal = true;
              } else {
                  Log.w(TAG, "Connection attempt failed.");
                  setConnectionState(State.DISCONNECTED, true);
                  retVal = false;
              }
          } else {
  
              final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
              if (device == null) {
                  Log.w(TAG, "Device not found.  Unable to connect.");
                  retVal = false;
              } else {
                  // We want to directly connect to the device, so we are setting the autoConnect
                  // parameter to false.
  
                  Log.d(TAG, "Trying to create a new connection.");
                  mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
                  mBluetoothDeviceAddress = address;
                  setConnectionState(State.CONNECTING, true);
                  retVal = true;
              }
          }
  
          return retVal;
      }
  
      private synchronized void setConnectionState(final State newState, final boolean broadCast) {
          Log.i(TAG, "Setting internal state to " + newState);
          mConnectionState = newState;
  
          final String broadcastAction;
  
          switch (newState) {
              case CONNECTED:
                  broadcastAction = ACTION_GATT_CONNECTED;
                  break;
              case CONNECTING:
                  broadcastAction = ACTION_GATT_CONNECTING;
                  break;
              case DISCONNECTED:
                  broadcastAction = ACTION_GATT_DISCONNECTED;
                  break;
              default:
                  throw new IllegalArgumentException("Unknown state: " + newState);
          }
  
          if (broadCast) {
              Log.i(TAG, "Broadcasting " + broadcastAction);
              broadcastUpdate(broadcastAction);
          }
  
      }
  
      /**
       * 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.
       */
      @SuppressLint("MissingPermission") // We check before this is called
      public void disconnect() {
          if (mBluetoothAdapter == null || mBluetoothGatt == null) {
              Log.w(TAG, "BluetoothAdapter not initialized");
              return;
          }
          mBluetoothGatt.disconnect();
  
          // Reusing a Gatt after disconnecting can cause problems
          mBluetoothGatt = null;
      }
  
      /**
       * 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();
      }
  
      /**
       * 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;
      }
  
      @Override
      public IBinder onBind(final Intent intent) {
          return mBinder;
      }
  
      @Override
      public boolean onUnbind(final 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);
      }
  
      /**
       * 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.
       */
      @SuppressLint("MissingPermission") // We check before this is called
      public void readCharacteristic(final 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.
       */
      @SuppressLint("MissingPermission") // We check before this is called
      public void setCharacteristicNotification(final BluetoothGattCharacteristic characteristic, final boolean enabled) {
          if (mBluetoothAdapter == null || mBluetoothGatt == null) {
              Log.w(TAG, "BluetoothAdapter not initialized");
              return;
          }
          mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
      }
  
  }