/*
 * Copyright (C) 2016 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.android.bluetooth.hid;

import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothHidDeviceAppConfiguration;
import android.bluetooth.BluetoothHidDeviceAppQosSettings;
import android.bluetooth.BluetoothHidDeviceAppSdpSettings;
import android.bluetooth.BluetoothInputHost;
import android.bluetooth.BluetoothProfile;
import android.bluetooth.IBluetoothHidDeviceCallback;
import android.bluetooth.IBluetoothInputHost;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.util.Log;

import com.android.bluetooth.Utils;
import com.android.bluetooth.btservice.ProfileService;

import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;
import java.util.NoSuchElementException;

/** @hide */
public class HidDevService extends ProfileService {
    private static final boolean DBG = false;

    private static final String TAG = HidDevService.class.getSimpleName();

    private static final int MESSAGE_APPLICATION_STATE_CHANGED = 1;
    private static final int MESSAGE_CONNECT_STATE_CHANGED = 2;
    private static final int MESSAGE_GET_REPORT = 3;
    private static final int MESSAGE_SET_REPORT = 4;
    private static final int MESSAGE_SET_PROTOCOL = 5;
    private static final int MESSAGE_INTR_DATA = 6;
    private static final int MESSAGE_VC_UNPLUG = 7;

    private boolean mNativeAvailable = false;

    private BluetoothDevice mHidDevice = null;

    private int mHidDeviceState = BluetoothInputHost.STATE_DISCONNECTED;

    private BluetoothHidDeviceAppConfiguration mAppConfig = null;

    private IBluetoothHidDeviceCallback mCallback = null;

    private BluetoothHidDeviceDeathRecipient mDeathRcpt;

    static {
        classInitNative();
    }

    private final Handler mHandler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            if (DBG) Log.v(TAG, "handleMessage(): msg.what=" + msg.what);

            switch (msg.what) {
                case MESSAGE_APPLICATION_STATE_CHANGED: {
                    BluetoothDevice device = msg.obj != null ? getDevice((byte[]) msg.obj) : null;
                    boolean success = (msg.arg1 != 0);

                    if (success) {
                        mHidDevice = device;
                    } else {
                        mHidDevice = null;
                    }

                    try {
                        if (mCallback != null)
                            mCallback.onAppStatusChanged(device, mAppConfig, success);
                        else
                            break;
                    } catch (RemoteException e) {
                        Log.e(TAG, "e=" + e.toString());
                        e.printStackTrace();
                    }

                    if (success) {
                        mDeathRcpt = new BluetoothHidDeviceDeathRecipient(
                                HidDevService.this, mAppConfig);
                        if (mCallback != null) {
                            IBinder binder = mCallback.asBinder();
                            try {
                                binder.linkToDeath(mDeathRcpt, 0);
                                Log.i(TAG, "IBinder.linkToDeath() ok");
                            } catch (RemoteException e) {
                                e.printStackTrace();
                            }
                        }
                    } else if (mDeathRcpt != null) {
                        if (mCallback != null) {
                            IBinder binder = mCallback.asBinder();
                            try {
                                binder.unlinkToDeath(mDeathRcpt, 0);
                                Log.i(TAG, "IBinder.unlinkToDeath() ok");
                            } catch (NoSuchElementException e) {
                                e.printStackTrace();
                            }
                            mDeathRcpt.cleanup();
                            mDeathRcpt = null;
                        }
                    }

                    if (!success) {
                        mAppConfig = null;
                        mCallback = null;
                    }

                    break;
                }

                case MESSAGE_CONNECT_STATE_CHANGED: {
                    BluetoothDevice device = getDevice((byte[]) msg.obj);
                    int halState = msg.arg1;
                    int state = convertHalState(halState);

                    if (state != BluetoothInputHost.STATE_DISCONNECTED) {
                        mHidDevice = device;
                    }

                    broadcastConnectionState(device, state);

                    try {
                        if (mCallback != null) mCallback.onConnectionStateChanged(device, state);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    break;
                }

                case MESSAGE_GET_REPORT:
                    byte type = (byte) msg.arg1;
                    byte id = (byte) msg.arg2;
                    int bufferSize = msg.obj == null ? 0 : ((Integer) msg.obj).intValue();

                    try {
                        if (mCallback != null)
                            mCallback.onGetReport(mHidDevice, type, id, bufferSize);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    break;

                case MESSAGE_SET_REPORT: {
                    byte reportType = (byte) msg.arg1;
                    byte reportId = (byte) msg.arg2;
                    byte[] data = ((ByteBuffer) msg.obj).array();

                    try {
                        if (mCallback != null)
                            mCallback.onSetReport(mHidDevice, reportType, reportId, data);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    break;
                }

                case MESSAGE_SET_PROTOCOL:
                    byte protocol = (byte) msg.arg1;

                    try {
                        if (mCallback != null) mCallback.onSetProtocol(mHidDevice, protocol);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    break;

                case MESSAGE_INTR_DATA:
                    byte reportId = (byte) msg.arg1;
                    byte[] data = ((ByteBuffer) msg.obj).array();

                    try {
                        if (mCallback != null) mCallback.onIntrData(mHidDevice, reportId, data);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    break;

                case MESSAGE_VC_UNPLUG:
                    try {
                        if (mCallback != null) mCallback.onVirtualCableUnplug(mHidDevice);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    mHidDevice = null;
                    break;
            }
        }
    };

    private static class BluetoothHidDeviceDeathRecipient implements IBinder.DeathRecipient {
        private HidDevService mService;
        private BluetoothHidDeviceAppConfiguration mAppConfig;

        public BluetoothHidDeviceDeathRecipient(
                HidDevService service, BluetoothHidDeviceAppConfiguration config) {
            mService = service;
            mAppConfig = config;
        }

        @Override
        public void binderDied() {
            Log.w(TAG, "Binder died, need to unregister app :(");
            mService.unregisterApp(mAppConfig);
        }

        public void cleanup() {
            mService = null;
            mAppConfig = null;
        }
  }

  private static class BluetoothHidDeviceBinder
      extends IBluetoothInputHost.Stub implements IProfileServiceBinder {

    private static final String TAG =
        BluetoothHidDeviceBinder.class.getSimpleName();

    private HidDevService mService;

    public BluetoothHidDeviceBinder(HidDevService service) {
      mService = service;
    }

    @Override
    public boolean cleanup() {
      mService = null;
      return true;
    }

    private HidDevService getService() {
      if (!Utils.checkCaller()) {
        Log.w(TAG, "HidDevice call not allowed for non-active user");
        return null;
      }

      if (mService != null && mService.isAvailable()) {
        return mService;
      }

      return null;
    }

    @Override
    public boolean registerApp(BluetoothHidDeviceAppConfiguration config,
                               BluetoothHidDeviceAppSdpSettings sdp,
                               BluetoothHidDeviceAppQosSettings inQos,
                               BluetoothHidDeviceAppQosSettings outQos,
                               IBluetoothHidDeviceCallback callback) {
      if (DBG)
        Log.v(TAG, "registerApp()");

      HidDevService service = getService();
      if (service == null) {
        return false;
      }

      return service.registerApp(config, sdp, inQos, outQos, callback);
    }

    @Override
    public boolean unregisterApp(BluetoothHidDeviceAppConfiguration config) {
      if (DBG)
        Log.v(TAG, "unregisterApp()");

      HidDevService service = getService();
      if (service == null) {
        return false;
      }

      return service.unregisterApp(config);
    }

    @Override
    public boolean sendReport(BluetoothDevice device, int id, byte[] data) {
        if (DBG) Log.v(TAG, "sendReport(): device=" + device + "  id=" + id);

        HidDevService service = getService();
        if (service == null) {
            return false;
        }

        return service.sendReport(device, id, data);
    }

    @Override
    public boolean replyReport(BluetoothDevice device, byte type, byte id, byte[] data) {
        if (DBG) Log.v(TAG, "replyReport(): device=" + device + " type=" + type + " id=" + id);

        HidDevService service = getService();
        if (service == null) {
            return false;
        }

        return service.replyReport(device, type, id, data);
    }

    @Override
    public boolean unplug(BluetoothDevice device) {
        if (DBG) Log.v(TAG, "unplug(): device=" + device);

        HidDevService service = getService();
        if (service == null) {
            return false;
        }

        return service.unplug(device);
    }

    @Override
    public boolean connect(BluetoothDevice device) {
        if (DBG) Log.v(TAG, "connect(): device=" + device);

        HidDevService service = getService();
        if (service == null) {
            return false;
        }

        return service.connect(device);
    }

    @Override
    public boolean disconnect(BluetoothDevice device) {
        if (DBG) Log.v(TAG, "disconnect(): device=" + device);

        HidDevService service = getService();
        if (service == null) {
            return false;
        }

        return service.disconnect(device);
    }

    @Override
    public boolean reportError(BluetoothDevice device, byte error) {
        if (DBG) Log.v(TAG, "reportError(): device=" + device + " error=" + error);

        HidDevService service = getService();
        if (service == null) {
            return false;
        }

        return service.reportError(device, error);
    }

    @Override
    public int getConnectionState(BluetoothDevice device) {
        if (DBG) Log.v(TAG, "getConnectionState(): device=" + device);

        HidDevService service = getService();
        if (service == null) {
            return BluetoothInputHost.STATE_DISCONNECTED;
        }

        return service.getConnectionState(device);
    }

    @Override
    public List<BluetoothDevice> getConnectedDevices() {
        if (DBG) Log.v(TAG, "getConnectedDevices()");

        return getDevicesMatchingConnectionStates(new int[] {BluetoothProfile.STATE_CONNECTED});
    }

    @Override
    public List<BluetoothDevice> getDevicesMatchingConnectionStates(int[] states) {
        if (DBG)
            Log.v(TAG, "getDevicesMatchingConnectionStates(): states=" + Arrays.toString(states));

        HidDevService service = getService();
        if (service == null) {
            return new ArrayList<BluetoothDevice>(0);
        }

        return service.getDevicesMatchingConnectionStates(states);
    }
  }

  @Override
  protected IProfileServiceBinder initBinder() {
    return new BluetoothHidDeviceBinder(this);
  }

  private boolean checkDevice(BluetoothDevice device) {
      if (mHidDevice == null || !mHidDevice.equals(device)) {
          Log.w(TAG, "Unknown device: " + device);
          return false;
      }
      return true;
  }

  synchronized boolean registerApp(BluetoothHidDeviceAppConfiguration config,
                                   BluetoothHidDeviceAppSdpSettings sdp,
                                   BluetoothHidDeviceAppQosSettings inQos,
                                   BluetoothHidDeviceAppQosSettings outQos,
                                   IBluetoothHidDeviceCallback callback) {
    if (DBG)
      Log.v(TAG, "registerApp()");

    if (mAppConfig != null) {
      return false;
    }

    mAppConfig = config;
    mCallback = callback;

    return registerAppNative(sdp.name, sdp.description, sdp.provider,
                             sdp.subclass, sdp.descriptors,
                             inQos == null ? null : inQos.toArray(),
                             outQos == null ? null : outQos.toArray());
  }

  synchronized boolean
  unregisterApp(BluetoothHidDeviceAppConfiguration config) {
    if (DBG)
      Log.v(TAG, "unregisterApp()");

    if (mAppConfig == null || config == null || !config.equals(mAppConfig)) {
      return false;
    }

    return unregisterAppNative();
  }

  synchronized boolean sendReport(BluetoothDevice device, int id, byte[] data) {
      if (DBG) Log.v(TAG, "sendReport(): device=" + device + " id=" + id);

      if (!checkDevice(device)) {
          return false;
      }

      return sendReportNative(id, data);
  }

  synchronized boolean replyReport(BluetoothDevice device, byte type, byte id, byte[] data) {
      if (DBG) Log.v(TAG, "replyReport(): device=" + device + " type=" + type + " id=" + id);

      if (!checkDevice(device)) {
          return false;
      }

      return replyReportNative(type, id, data);
  }

  synchronized boolean unplug(BluetoothDevice device) {
      if (DBG) Log.v(TAG, "unplug(): device=" + device);

      if (!checkDevice(device)) {
          return false;
      }

      return unplugNative();
  }

  synchronized boolean connect(BluetoothDevice device) {
      if (DBG) Log.v(TAG, "connect(): device=" + device);

      return connectNative(Utils.getByteAddress(device));
  }

  synchronized boolean disconnect(BluetoothDevice device) {
      if (DBG) Log.v(TAG, "disconnect(): device=" + device);

      if (!checkDevice(device)) {
          return false;
      }

      return disconnectNative();
  }

  synchronized boolean reportError(BluetoothDevice device, byte error) {
      if (DBG) Log.v(TAG, "reportError(): device=" + device + " error=" + error);

      if (!checkDevice(device)) {
          return false;
      }

      return reportErrorNative(error);
  }

  @Override
  protected boolean start() {
    if (DBG)
      Log.d(TAG, "start()");

    initNative();
    mNativeAvailable = true;

    return true;
  }

  @Override
  protected boolean stop() {
    if (DBG)
      Log.d(TAG, "stop()");

    return true;
  }

  @Override
  protected boolean cleanup() {
    if (DBG)
      Log.d(TAG, "cleanup()");

    if (mNativeAvailable) {
      cleanupNative();
      mNativeAvailable = false;
    }

    return true;
  }

  int getConnectionState(BluetoothDevice device) {
      if (mHidDevice != null && mHidDevice.equals(device)) {
          return mHidDeviceState;
      }
      return BluetoothInputHost.STATE_DISCONNECTED;
  }

  List<BluetoothDevice> getDevicesMatchingConnectionStates(int[] states) {
      enforceCallingOrSelfPermission(BLUETOOTH_PERM, "Need BLUETOOTH permission");
      List<BluetoothDevice> inputDevices = new ArrayList<BluetoothDevice>();

      if (mHidDevice != null) {
          for (int state : states) {
              if (state == mHidDeviceState) {
                  inputDevices.add(mHidDevice);
                  break;
              }
          }
      }
      return inputDevices;
  }

  private synchronized void onApplicationStateChanged(byte[] address,
                                                      boolean registered) {
    if (DBG)
      Log.v(TAG, "onApplicationStateChanged(): registered=" + registered);

    Message msg = mHandler.obtainMessage(MESSAGE_APPLICATION_STATE_CHANGED);
    msg.obj = address;
    msg.arg1 = registered ? 1 : 0;
    mHandler.sendMessage(msg);
  }

  private synchronized void onConnectStateChanged(byte[] address, int state) {
    if (DBG)
      Log.v(TAG, "onConnectStateChanged(): address=" +
                     Arrays.toString(address) + " state=" + state);

    Message msg = mHandler.obtainMessage(MESSAGE_CONNECT_STATE_CHANGED);
    msg.obj = address;
    msg.arg1 = state;
    mHandler.sendMessage(msg);
  }

  private synchronized void onGetReport(byte type, byte id, short bufferSize) {
    if (DBG)
      Log.v(TAG, "onGetReport(): type=" + type + " id=" + id + " bufferSize=" +
                     bufferSize);

    Message msg = mHandler.obtainMessage(MESSAGE_GET_REPORT);
    msg.obj = bufferSize > 0 ? new Integer(bufferSize) : null;
    msg.arg1 = type;
    msg.arg2 = id;
    mHandler.sendMessage(msg);
  }

  private synchronized void onSetReport(byte reportType, byte reportId,
                                        byte[] data) {
    if (DBG)
      Log.v(TAG, "onSetReport(): reportType=" + reportType + " reportId=" +
                     reportId);

    ByteBuffer bb = ByteBuffer.wrap(data);

    Message msg = mHandler.obtainMessage(MESSAGE_SET_REPORT);
    msg.arg1 = reportType;
    msg.arg2 = reportId;
    msg.obj = bb;
    mHandler.sendMessage(msg);
  }

  private synchronized void onSetProtocol(byte protocol) {
    if (DBG)
      Log.v(TAG, "onSetProtocol(): protocol=" + protocol);

    Message msg = mHandler.obtainMessage(MESSAGE_SET_PROTOCOL);
    msg.arg1 = protocol;
    mHandler.sendMessage(msg);
  }

  private synchronized void onIntrData(byte reportId, byte[] data) {
    if (DBG)
      Log.v(TAG, "onIntrData(): reportId=" + reportId);

    ByteBuffer bb = ByteBuffer.wrap(data);

    Message msg = mHandler.obtainMessage(MESSAGE_INTR_DATA);
    msg.arg1 = reportId;
    msg.obj = bb;
    mHandler.sendMessage(msg);
  }

  private synchronized void onVirtualCableUnplug() {
    if (DBG)
      Log.v(TAG, "onVirtualCableUnplug()");

    Message msg = mHandler.obtainMessage(MESSAGE_VC_UNPLUG);
    mHandler.sendMessage(msg);
  }

  private void broadcastConnectionState(BluetoothDevice device, int newState) {
    if (DBG)
      Log.v(TAG, "broadcastConnectionState(): device=" + device.getAddress() +
                     " newState=" + newState);

    if (mHidDevice != null && !mHidDevice.equals(device)) {
        Log.w(TAG, "Connection state changed for unknown device, ignoring");
        return;
    }

    int prevState = mHidDeviceState;
    mHidDeviceState = newState;

    Log.i(TAG, "connection state for " + device.getAddress() + ": " +
                   prevState + " -> " + newState);

    if (prevState == newState) {
      return;
    }

    Intent intent =
        new Intent(BluetoothInputHost.ACTION_CONNECTION_STATE_CHANGED);
    intent.putExtra(BluetoothProfile.EXTRA_PREVIOUS_STATE, prevState);
    intent.putExtra(BluetoothProfile.EXTRA_STATE, newState);
    intent.putExtra(BluetoothDevice.EXTRA_DEVICE, device);
    intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
    sendBroadcast(intent, BLUETOOTH_PERM);
  }

  private static int convertHalState(int halState) {
    switch (halState) {
    case CONN_STATE_CONNECTED:
      return BluetoothProfile.STATE_CONNECTED;
    case CONN_STATE_CONNECTING:
      return BluetoothProfile.STATE_CONNECTING;
    case CONN_STATE_DISCONNECTED:
      return BluetoothProfile.STATE_DISCONNECTED;
    case CONN_STATE_DISCONNECTING:
      return BluetoothProfile.STATE_DISCONNECTING;
    default:
      return BluetoothProfile.STATE_DISCONNECTED;
    }
  }

  private final static int CONN_STATE_CONNECTED = 0;
  private final static int CONN_STATE_CONNECTING = 1;
  private final static int CONN_STATE_DISCONNECTED = 2;
  private final static int CONN_STATE_DISCONNECTING = 3;

  private native static void classInitNative();
  private native void initNative();
  private native void cleanupNative();
  private native boolean registerAppNative(String name, String description,
                                           String provider, byte subclass,
                                           byte[] descriptors, int[] inQos,
                                           int[] outQos);
  private native boolean unregisterAppNative();
  private native boolean sendReportNative(int id, byte[] data);
  private native boolean replyReportNative(byte type, byte id, byte[] data);
  private native boolean unplugNative();
  private native boolean connectNative(byte[] btAddress);
  private native boolean disconnectNative();
  private native boolean reportErrorNative(byte error);
}