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.app.ActionBar;
  import android.app.Activity;
  import android.bluetooth.BluetoothAdapter;
  import android.bluetooth.BluetoothDevice;
  import android.content.Intent;
  import android.os.Bundle;
  import android.os.Handler;
  import android.os.Message;
  import android.view.KeyEvent;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuInflater;
  import android.view.MenuItem;
  import android.view.View;
  import android.view.ViewGroup;
  import android.view.inputmethod.EditorInfo;
  import android.widget.ArrayAdapter;
  import android.widget.Button;
  import android.widget.EditText;
  import android.widget.ListView;
  import android.widget.TextView;
  import android.widget.Toast;
  
  import androidx.annotation.NonNull;
  import androidx.annotation.Nullable;
  import androidx.fragment.app.Fragment;
  import androidx.fragment.app.FragmentActivity;
  
  import com.example.android.common.logger.Log;
  
  /**
   * This fragment controls Bluetooth to communicate with other devices.
   */
  public class BluetoothChatFragment extends Fragment {
  
      private static final String TAG = "BluetoothChatFragment";
  
      // Intent request codes
      private static final int REQUEST_CONNECT_DEVICE_SECURE = 1;
      private static final int REQUEST_CONNECT_DEVICE_INSECURE = 2;
      private static final int REQUEST_ENABLE_BT = 3;
  
      // Layout Views
      private ListView mConversationView;
      private EditText mOutEditText;
      private Button mSendButton;
  
      /**
       * Name of the connected device
       */
      private String mConnectedDeviceName = null;
  
      /**
       * Array adapter for the conversation thread
       */
      private ArrayAdapter<String> mConversationArrayAdapter;
  
      /**
       * String buffer for outgoing messages
       */
      private StringBuffer mOutStringBuffer;
  
      /**
       * Local Bluetooth adapter
       */
      private BluetoothAdapter mBluetoothAdapter = null;
  
      /**
       * Member object for the chat services
       */
      private BluetoothChatService mChatService = null;
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setHasOptionsMenu(true);
          // Get local Bluetooth adapter
          mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
  
          // If the adapter is null, then Bluetooth is not supported
          FragmentActivity activity = getActivity();
          if (mBluetoothAdapter == null && activity != null) {
              Toast.makeText(activity, "Bluetooth is not available", Toast.LENGTH_LONG).show();
              activity.finish();
          }
      }
  
      @Override
      public void onStart() {
          super.onStart();
          if (mBluetoothAdapter == null) {
              return;
          }
          // If BT is not on, request that it be enabled.
          // setupChat() will then be called during onActivityResult
          if (!mBluetoothAdapter.isEnabled()) {
              Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
              startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
              // Otherwise, setup the chat session
          } else if (mChatService == null) {
              setupChat();
          }
      }
  
      @Override
      public void onDestroy() {
          super.onDestroy();
          if (mChatService != null) {
              mChatService.stop();
          }
      }
  
      @Override
      public void onResume() {
          super.onResume();
  
          // Performing this check in onResume() covers the case in which BT was
          // not enabled during onStart(), so we were paused to enable it...
          // onResume() will be called when ACTION_REQUEST_ENABLE activity returns.
          if (mChatService != null) {
              // Only if the state is STATE_NONE, do we know that we haven't started already
              if (mChatService.getState() == BluetoothChatService.STATE_NONE) {
                  // Start the Bluetooth chat services
                  mChatService.start();
              }
          }
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                               @Nullable Bundle savedInstanceState) {
          return inflater.inflate(R.layout.fragment_bluetooth_chat, container, false);
      }
  
      @Override
      public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
          mConversationView = view.findViewById(R.id.in);
          mOutEditText = view.findViewById(R.id.edit_text_out);
          mSendButton = view.findViewById(R.id.button_send);
      }
  
      /**
       * Set up the UI and background operations for chat.
       */
      private void setupChat() {
          Log.d(TAG, "setupChat()");
  
          // Initialize the array adapter for the conversation thread
          FragmentActivity activity = getActivity();
          if (activity == null) {
              return;
          }
          mConversationArrayAdapter = new ArrayAdapter<>(activity, R.layout.message);
  
          mConversationView.setAdapter(mConversationArrayAdapter);
  
          // Initialize the compose field with a listener for the return key
          mOutEditText.setOnEditorActionListener(mWriteListener);
  
          // Initialize the send button with a listener that for click events
          mSendButton.setOnClickListener(new View.OnClickListener() {
              public void onClick(View v) {
                  // Send a message using content of the edit text widget
                  View view = getView();
                  if (null != view) {
                      TextView textView = view.findViewById(R.id.edit_text_out);
                      String message = textView.getText().toString();
                      sendMessage(message);
                  }
              }
          });
  
          // Initialize the BluetoothChatService to perform bluetooth connections
          mChatService = new BluetoothChatService(activity, mHandler);
  
          // Initialize the buffer for outgoing messages
          mOutStringBuffer = new StringBuffer();
      }
  
      /**
       * Makes this device discoverable for 300 seconds (5 minutes).
       */
      private void ensureDiscoverable() {
          if (mBluetoothAdapter.getScanMode() !=
                  BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
              Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
              discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
              startActivity(discoverableIntent);
          }
      }
  
      /**
       * Sends a message.
       *
       * @param message A string of text to send.
       */
      private void sendMessage(String message) {
          // Check that we're actually connected before trying anything
          if (mChatService.getState() != BluetoothChatService.STATE_CONNECTED) {
              Toast.makeText(getActivity(), R.string.not_connected, Toast.LENGTH_SHORT).show();
              return;
          }
  
          // Check that there's actually something to send
          if (message.length() > 0) {
              // Get the message bytes and tell the BluetoothChatService to write
              byte[] send = message.getBytes();
              mChatService.write(send);
  
              // Reset out string buffer to zero and clear the edit text field
              mOutStringBuffer.setLength(0);
              mOutEditText.setText(mOutStringBuffer);
          }
      }
  
      /**
       * The action listener for the EditText widget, to listen for the return key
       */
      private TextView.OnEditorActionListener mWriteListener
              = new TextView.OnEditorActionListener() {
          public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
              // If the action is a key-up event on the return key, send the message
              if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) {
                  String message = view.getText().toString();
                  sendMessage(message);
              }
              return true;
          }
      };
  
      /**
       * Updates the status on the action bar.
       *
       * @param resId a string resource ID
       */
      private void setStatus(int resId) {
          FragmentActivity activity = getActivity();
          if (null == activity) {
              return;
          }
          final ActionBar actionBar = activity.getActionBar();
          if (null == actionBar) {
              return;
          }
          actionBar.setSubtitle(resId);
      }
  
      /**
       * Updates the status on the action bar.
       *
       * @param subTitle status
       */
      private void setStatus(CharSequence subTitle) {
          FragmentActivity activity = getActivity();
          if (null == activity) {
              return;
          }
          final ActionBar actionBar = activity.getActionBar();
          if (null == actionBar) {
              return;
          }
          actionBar.setSubtitle(subTitle);
      }
  
      /**
       * The Handler that gets information back from the BluetoothChatService
       */
      private final Handler mHandler = new Handler() {
          @Override
          public void handleMessage(Message msg) {
              FragmentActivity activity = getActivity();
              switch (msg.what) {
                  case Constants.MESSAGE_STATE_CHANGE:
                      switch (msg.arg1) {
                          case BluetoothChatService.STATE_CONNECTED:
                              setStatus(getString(R.string.title_connected_to, mConnectedDeviceName));
                              mConversationArrayAdapter.clear();
                              break;
                          case BluetoothChatService.STATE_CONNECTING:
                              setStatus(R.string.title_connecting);
                              break;
                          case BluetoothChatService.STATE_LISTEN:
                          case BluetoothChatService.STATE_NONE:
                              setStatus(R.string.title_not_connected);
                              break;
                      }
                      break;
                  case Constants.MESSAGE_WRITE:
                      byte[] writeBuf = (byte[]) msg.obj;
                      // construct a string from the buffer
                      String writeMessage = new String(writeBuf);
                      mConversationArrayAdapter.add("Me:  " + writeMessage);
                      break;
                  case Constants.MESSAGE_READ:
                      byte[] readBuf = (byte[]) msg.obj;
                      // construct a string from the valid bytes in the buffer
                      String readMessage = new String(readBuf, 0, msg.arg1);
                      mConversationArrayAdapter.add(mConnectedDeviceName + ":  " + readMessage);
                      break;
                  case Constants.MESSAGE_DEVICE_NAME:
                      // save the connected device's name
                      mConnectedDeviceName = msg.getData().getString(Constants.DEVICE_NAME);
                      if (null != activity) {
                          Toast.makeText(activity, "Connected to "
                                  + mConnectedDeviceName, Toast.LENGTH_SHORT).show();
                      }
                      break;
                  case Constants.MESSAGE_TOAST:
                      if (null != activity) {
                          Toast.makeText(activity, msg.getData().getString(Constants.TOAST),
                                  Toast.LENGTH_SHORT).show();
                      }
                      break;
              }
          }
      };
  
      public void onActivityResult(int requestCode, int resultCode, Intent data) {
          switch (requestCode) {
              case REQUEST_CONNECT_DEVICE_SECURE:
                  // When DeviceListActivity returns with a device to connect
                  if (resultCode == Activity.RESULT_OK) {
                      connectDevice(data, true);
                  }
                  break;
              case REQUEST_CONNECT_DEVICE_INSECURE:
                  // When DeviceListActivity returns with a device to connect
                  if (resultCode == Activity.RESULT_OK) {
                      connectDevice(data, false);
                  }
                  break;
              case REQUEST_ENABLE_BT:
                  // When the request to enable Bluetooth returns
                  if (resultCode == Activity.RESULT_OK) {
                      // Bluetooth is now enabled, so set up a chat session
                      setupChat();
                  } else {
                      // User did not enable Bluetooth or an error occurred
                      Log.d(TAG, "BT not enabled");
                      FragmentActivity activity = getActivity();
                      if (activity != null) {
                          Toast.makeText(activity, R.string.bt_not_enabled_leaving,
                                  Toast.LENGTH_SHORT).show();
                          activity.finish();
                      }
                  }
          }
      }
  
      /**
       * Establish connection with other device
       *
       * @param data   An {@link Intent} with {@link DeviceListActivity#EXTRA_DEVICE_ADDRESS} extra.
       * @param secure Socket Security type - Secure (true) , Insecure (false)
       */
      private void connectDevice(Intent data, boolean secure) {
          // Get the device MAC address
          Bundle extras = data.getExtras();
          if (extras == null) {
              return;
          }
          String address = extras.getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
          // Get the BluetoothDevice object
          BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
          // Attempt to connect to the device
          mChatService.connect(device, secure);
      }
  
      @Override
      public void onCreateOptionsMenu(@NonNull Menu menu, MenuInflater inflater) {
          inflater.inflate(R.menu.bluetooth_chat, menu);
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          switch (item.getItemId()) {
              case R.id.secure_connect_scan: {
                  // Launch the DeviceListActivity to see devices and do scan
                  Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class);
                  startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE);
                  return true;
              }
              case R.id.insecure_connect_scan: {
                  // Launch the DeviceListActivity to see devices and do scan
                  Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class);
                  startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_INSECURE);
                  return true;
              }
              case R.id.discoverable: {
                  // Ensure this device is discoverable by others
                  ensureDiscoverable();
                  return true;
              }
          }
          return false;
      }
  
  }
  