content: /*
   * Copyright (C) 2014 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.bluetoothchat;
  
  import android.bluetooth.BluetoothAdapter;
  import android.bluetooth.BluetoothDevice;
  import android.bluetooth.BluetoothServerSocket;
  import android.bluetooth.BluetoothSocket;
  import android.content.Context;
  import android.os.Bundle;
  import android.os.Handler;
  import android.os.Message;
  
  import com.example.android.common.logger.Log;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.UUID;
  
  /**
   * This class does all the work for setting up and managing Bluetooth
   * connections with other devices. It has a thread that listens for
   * incoming connections, a thread for connecting with a device, and a
   * thread for performing data transmissions when connected.
   */
  public class BluetoothChatService {
      // Debugging
      private static final String TAG = "BluetoothChatService";
  
      // Name for the SDP record when creating server socket
      private static final String NAME_SECURE = "BluetoothChatSecure";
      private static final String NAME_INSECURE = "BluetoothChatInsecure";
  
      // Unique UUID for this application
      private static final UUID MY_UUID_SECURE =
              UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
      private static final UUID MY_UUID_INSECURE =
              UUID.fromString("8ce255c0-200a-11e0-ac64-0800200c9a66");
  
      // Member fields
      private final BluetoothAdapter mAdapter;
      private final Handler mHandler;
      private AcceptThread mSecureAcceptThread;
      private AcceptThread mInsecureAcceptThread;
      private ConnectThread mConnectThread;
      private ConnectedThread mConnectedThread;
      private int mState;
      private int mNewState;
  
      // Constants that indicate the current connection state
      public static final int STATE_NONE = 0;       // we're doing nothing
      public static final int STATE_LISTEN = 1;     // now listening for incoming connections
      public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
      public static final int STATE_CONNECTED = 3;  // now connected to a remote device
  
      /**
       * Constructor. Prepares a new BluetoothChat session.
       *
       * @param context The UI Activity Context
       * @param handler A Handler to send messages back to the UI Activity
       */
      public BluetoothChatService(Context context, Handler handler) {
          mAdapter = BluetoothAdapter.getDefaultAdapter();
          mState = STATE_NONE;
          mNewState = mState;
          mHandler = handler;
      }
  
      /**
       * Update UI title according to the current state of the chat connection
       */
      private synchronized void updateUserInterfaceTitle() {
          mState = getState();
          Log.d(TAG, "updateUserInterfaceTitle() " + mNewState + " -> " + mState);
          mNewState = mState;
  
          // Give the new state to the Handler so the UI Activity can update
          mHandler.obtainMessage(Constants.MESSAGE_STATE_CHANGE, mNewState, -1).sendToTarget();
      }
  
      /**
       * Return the current connection state.
       */
      public synchronized int getState() {
          return mState;
      }
  
      /**
       * Start the chat service. Specifically start AcceptThread to begin a
       * session in listening (server) mode. Called by the Activity onResume()
       */
      public synchronized void start() {
          Log.d(TAG, "start");
  
          // Cancel any thread attempting to make a connection
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          // Cancel any thread currently running a connection
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          // Start the thread to listen on a BluetoothServerSocket
          if (mSecureAcceptThread == null) {
              mSecureAcceptThread = new AcceptThread(true);
              mSecureAcceptThread.start();
          }
          if (mInsecureAcceptThread == null) {
              mInsecureAcceptThread = new AcceptThread(false);
              mInsecureAcceptThread.start();
          }
          // Update UI title
          updateUserInterfaceTitle();
      }
  
      /**
       * Start the ConnectThread to initiate a connection to a remote device.
       *
       * @param device The BluetoothDevice to connect
       * @param secure Socket Security type - Secure (true) , Insecure (false)
       */
      public synchronized void connect(BluetoothDevice device, boolean secure) {
          Log.d(TAG, "connect to: " + device);
  
          // Cancel any thread attempting to make a connection
          if (mState == STATE_CONNECTING) {
              if (mConnectThread != null) {
                  mConnectThread.cancel();
                  mConnectThread = null;
              }
          }
  
          // Cancel any thread currently running a connection
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          // Start the thread to connect with the given device
          mConnectThread = new ConnectThread(device, secure);
          mConnectThread.start();
          // Update UI title
          updateUserInterfaceTitle();
      }
  
      /**
       * Start the ConnectedThread to begin managing a Bluetooth connection
       *
       * @param socket The BluetoothSocket on which the connection was made
       * @param device The BluetoothDevice that has been connected
       */
      public synchronized void connected(BluetoothSocket socket, BluetoothDevice
              device, final String socketType) {
          Log.d(TAG, "connected, Socket Type:" + socketType);
  
          // Cancel the thread that completed the connection
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          // Cancel any thread currently running a connection
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          // Cancel the accept thread because we only want to connect to one device
          if (mSecureAcceptThread != null) {
              mSecureAcceptThread.cancel();
              mSecureAcceptThread = null;
          }
          if (mInsecureAcceptThread != null) {
              mInsecureAcceptThread.cancel();
              mInsecureAcceptThread = null;
          }
  
          // Start the thread to manage the connection and perform transmissions
          mConnectedThread = new ConnectedThread(socket, socketType);
          mConnectedThread.start();
  
          // Send the name of the connected device back to the UI Activity
          Message msg = mHandler.obtainMessage(Constants.MESSAGE_DEVICE_NAME);
          Bundle bundle = new Bundle();
          bundle.putString(Constants.DEVICE_NAME, device.getName());
          msg.setData(bundle);
          mHandler.sendMessage(msg);
          // Update UI title
          updateUserInterfaceTitle();
      }
  
      /**
       * Stop all threads
       */
      public synchronized void stop() {
          Log.d(TAG, "stop");
  
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          if (mSecureAcceptThread != null) {
              mSecureAcceptThread.cancel();
              mSecureAcceptThread = null;
          }
  
          if (mInsecureAcceptThread != null) {
              mInsecureAcceptThread.cancel();
              mInsecureAcceptThread = null;
          }
          mState = STATE_NONE;
          // Update UI title
          updateUserInterfaceTitle();
      }
  
      /**
       * Write to the ConnectedThread in an unsynchronized manner
       *
       * @param out The bytes to write
       * @see ConnectedThread#write(byte[])
       */
      public void write(byte[] out) {
          // Create temporary object
          ConnectedThread r;
          // Synchronize a copy of the ConnectedThread
          synchronized (this) {
              if (mState != STATE_CONNECTED) return;
              r = mConnectedThread;
          }
          // Perform the write unsynchronized
          r.write(out);
      }
  
      /**
       * Indicate that the connection attempt failed and notify the UI Activity.
       */
      private void connectionFailed() {
          // Send a failure message back to the Activity
          Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
          Bundle bundle = new Bundle();
          bundle.putString(Constants.TOAST, "Unable to connect device");
          msg.setData(bundle);
          mHandler.sendMessage(msg);
  
          mState = STATE_NONE;
          // Update UI title
          updateUserInterfaceTitle();
  
          // Start the service over to restart listening mode
          BluetoothChatService.this.start();
      }
  
      /**
       * Indicate that the connection was lost and notify the UI Activity.
       */
      private void connectionLost() {
          // Send a failure message back to the Activity
          Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
          Bundle bundle = new Bundle();
          bundle.putString(Constants.TOAST, "Device connection was lost");
          msg.setData(bundle);
          mHandler.sendMessage(msg);
  
          mState = STATE_NONE;
          // Update UI title
          updateUserInterfaceTitle();
  
          // Start the service over to restart listening mode
          BluetoothChatService.this.start();
      }
  
      /**
       * This thread runs while listening for incoming connections. It behaves
       * like a server-side client. It runs until a connection is accepted
       * (or until cancelled).
       */
      private class AcceptThread extends Thread {
          // The local server socket
          private final BluetoothServerSocket mmServerSocket;
          private String mSocketType;
  
          public AcceptThread(boolean secure) {
              BluetoothServerSocket tmp = null;
              mSocketType = secure ? "Secure" : "Insecure";
  
              // Create a new listening server socket
              try {
                  if (secure) {
                      tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE,
                              MY_UUID_SECURE);
                  } else {
                      tmp = mAdapter.listenUsingInsecureRfcommWithServiceRecord(
                              NAME_INSECURE, MY_UUID_INSECURE);
                  }
              } catch (IOException e) {
                  Log.e(TAG, "Socket Type: " + mSocketType + "listen() failed", e);
              }
              mmServerSocket = tmp;
              mState = STATE_LISTEN;
          }
  
          public void run() {
              Log.d(TAG, "Socket Type: " + mSocketType +
                      "BEGIN mAcceptThread" + this);
              setName("AcceptThread" + mSocketType);
  
              BluetoothSocket socket;
  
              // Listen to the server socket if we're not connected
              while (mState != STATE_CONNECTED) {
                  try {
                      // This is a blocking call and will only return on a
                      // successful connection or an exception
                      socket = mmServerSocket.accept();
                  } catch (IOException e) {
                      Log.e(TAG, "Socket Type: " + mSocketType + "accept() failed", e);
                      break;
                  }
  
                  // If a connection was accepted
                  if (socket != null) {
                      synchronized (BluetoothChatService.this) {
                          switch (mState) {
                              case STATE_LISTEN:
                              case STATE_CONNECTING:
                                  // Situation normal. Start the connected thread.
                                  connected(socket, socket.getRemoteDevice(),
                                          mSocketType);
                                  break;
                              case STATE_NONE:
                              case STATE_CONNECTED:
                                  // Either not ready or already connected. Terminate new socket.
                                  try {
                                      socket.close();
                                  } catch (IOException e) {
                                      Log.e(TAG, "Could not close unwanted socket", e);
                                  }
                                  break;
                          }
                      }
                  }
              }
              Log.i(TAG, "END mAcceptThread, socket Type: " + mSocketType);
  
          }
  
          public void cancel() {
              Log.d(TAG, "Socket Type" + mSocketType + "cancel " + this);
              try {
                  mmServerSocket.close();
              } catch (IOException e) {
                  Log.e(TAG, "Socket Type" + mSocketType + "close() of server failed", e);
              }
          }
      }
  
  
      /**
       * This thread runs while attempting to make an outgoing connection
       * with a device. It runs straight through; the connection either
       * succeeds or fails.
       */
      private class ConnectThread extends Thread {
          private final BluetoothSocket mmSocket;
          private final BluetoothDevice mmDevice;
          private String mSocketType;
  
          public ConnectThread(BluetoothDevice device, boolean secure) {
              mmDevice = device;
              BluetoothSocket tmp = null;
              mSocketType = secure ? "Secure" : "Insecure";
  
              // Get a BluetoothSocket for a connection with the
              // given BluetoothDevice
              try {
                  if (secure) {
                      tmp = device.createRfcommSocketToServiceRecord(
                              MY_UUID_SECURE);
                  } else {
                      tmp = device.createInsecureRfcommSocketToServiceRecord(
                              MY_UUID_INSECURE);
                  }
              } catch (IOException e) {
                  Log.e(TAG, "Socket Type: " + mSocketType + "create() failed", e);
              }
              mmSocket = tmp;
              mState = STATE_CONNECTING;
          }
  
          public void run() {
              Log.i(TAG, "BEGIN mConnectThread SocketType:" + mSocketType);
              setName("ConnectThread" + mSocketType);
  
              // Always cancel discovery because it will slow down a connection
              mAdapter.cancelDiscovery();
  
              // Make a connection to the BluetoothSocket
              try {
                  // This is a blocking call and will only return on a
                  // successful connection or an exception
                  mmSocket.connect();
              } catch (IOException e) {
                  // Close the socket
                  try {
                      mmSocket.close();
                  } catch (IOException e2) {
                      Log.e(TAG, "unable to close() " + mSocketType +
                              " socket during connection failure", e2);
                  }
                  connectionFailed();
                  return;
              }
  
              // Reset the ConnectThread because we're done
              synchronized (BluetoothChatService.this) {
                  mConnectThread = null;
              }
  
              // Start the connected thread
              connected(mmSocket, mmDevice, mSocketType);
          }
  
          public void cancel() {
              try {
                  mmSocket.close();
              } catch (IOException e) {
                  Log.e(TAG, "close() of connect " + mSocketType + " socket failed", e);
              }
          }
      }
  
      /**
       * This thread runs during a connection with a remote device.
       * It handles all incoming and outgoing transmissions.
       */
      private class ConnectedThread extends Thread {
          private final BluetoothSocket mmSocket;
          private final InputStream mmInStream;
          private final OutputStream mmOutStream;
  
          public ConnectedThread(BluetoothSocket socket, String socketType) {
              Log.d(TAG, "create ConnectedThread: " + socketType);
              mmSocket = socket;
              InputStream tmpIn = null;
              OutputStream tmpOut = null;
  
              // Get the BluetoothSocket input and output streams
              try {
                  tmpIn = socket.getInputStream();
                  tmpOut = socket.getOutputStream();
              } catch (IOException e) {
                  Log.e(TAG, "temp sockets not created", e);
              }
  
              mmInStream = tmpIn;
              mmOutStream = tmpOut;
              mState = STATE_CONNECTED;
          }
  
          public void run() {
              Log.i(TAG, "BEGIN mConnectedThread");
              byte[] buffer = new byte[1024];
              int bytes;
  
              // Keep listening to the InputStream while connected
              while (mState == STATE_CONNECTED) {
                  try {
                      // Read from the InputStream
                      bytes = mmInStream.read(buffer);
  
                      // Send the obtained bytes to the UI Activity
                      mHandler.obtainMessage(Constants.MESSAGE_READ, bytes, -1, buffer)
                              .sendToTarget();
                  } catch (IOException e) {
                      Log.e(TAG, "disconnected", e);
                      connectionLost();
                      break;
                  }
              }
          }
  
          /**
           * Write to the connected OutStream.
           *
           * @param buffer The bytes to write
           */
          public void write(byte[] buffer) {
              try {
                  mmOutStream.write(buffer);
  
                  // Share the sent message back to the UI Activity
                  mHandler.obtainMessage(Constants.MESSAGE_WRITE, -1, -1, buffer)
                          .sendToTarget();
              } catch (IOException e) {
                  Log.e(TAG, "Exception during write", e);
              }
          }
  
          public void cancel() {
              try {
                  mmSocket.close();
              } catch (IOException e) {
                  Log.e(TAG, "close() of connect socket failed", e);
              }
          }
      }
  }
  