/*
 * Copyright (c) 2015, Nordic Semiconductor
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package no.nordicsemi.android.nrfbeacon;

import java.lang.reflect.Method;
import java.util.UUID;

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.Intent;
import android.os.Binder;
import android.os.Handler;
import android.os.IBinder;
import android.os.ParcelUuid;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import android.util.Pair;

public class UpdateService extends Service {
	private static final String TAG = "UpdateService";

	public final static String ACTION_STATE_CHANGED = "no.nordicsemi.android.nrfbeacon.ACTION_STATE_CHANGED";
	public final static String ACTION_GATT_ERROR = "no.nordicsemi.android.nrfbeacon.ACTION_GATT_ERROR";
	public final static String ACTION_DONE = "no.nordicsemi.android.nrfbeacon.ACTION_DONE";
	public final static String ACTION_UUID_READY = "no.nordicsemi.android.nrfbeacon.ACTION_UUID_READY";
	public final static String ACTION_MAJOR_MINOR_READY = "no.nordicsemi.android.nrfbeacon.ACTION_MAJOR_MINOR_READY";
	public final static String ACTION_RSSI_READY = "no.nordicsemi.android.nrfbeacon.ACTION_RSSI_READY";
	public final static String ACTION_MANUFACTURER_ID_READY = "no.nordicsemi.android.nrfbeacon.ACTION_MANUFACTURER_ID_READY";
	public final static String ACTION_ADV_INTERVAL_READY = "no.nordicsemi.android.nrfbeacon.ACTION_ADV_INTERVAL_READY";
	public final static String ACTION_LED_STATUS_READY = "no.nordicsemi.android.nrfbeacon.ACTION_LED_STATUS_READY";

	public final static String EXTRA_DATA = "no.nordicsemi.android.nrfbeacon.EXTRA_DATA";
	public final static String EXTRA_MAJOR = "no.nordicsemi.android.nrfbeacon.EXTRA_MAJOR";
	public final static String EXTRA_MINOR = "no.nordicsemi.android.nrfbeacon.EXTRA_MINOR";

	public final static int ERROR_UNSUPPORTED_DEVICE = -1;

	private int mConnectionState;
	public final static int STATE_DISCONNECTED = 0;
	public final static int STATE_CONNECTING = 1;
	public final static int STATE_DISCOVERING_SERVICES = 2;
	public final static int STATE_CONNECTED = 3;
	public final static int STATE_DISCONNECTING = 4;

	public final static int SERVICE_UUID = 1;
	public final static int SERVICE_MAJOR_MINOR = 2;
	public final static int SERVICE_CALIBRATION = 3;

	public static final UUID CONFIG_SERVICE_UUID = new UUID(0x955A15230FE2F5AAl, 0xA09484B8D4F3E8ADl);
	private static final UUID CONFIG_UUID_CHARACTERISTIC_UUID = new UUID(0x955A15240FE2F5AAl, 0xA09484B8D4F3E8ADl);
	private static final UUID CONFIG_RSSI_CHARACTERISTIC_UUID = new UUID(0x955A15250FE2F5AAl, 0xA09484B8D4F3E8ADl);
	private static final UUID CONFIG_MAJOR_MINOR_CHARACTERISTIC_UUID = new UUID(0x955A15260FE2F5AAl, 0xA09484B8D4F3E8ADl);
	private static final UUID CONFIG_MANUFACTURER_ID_CHARACTERISTIC_UUID = new UUID(0x955A15270FE2F5AAl, 0xA09484B8D4F3E8ADl);
	private static final UUID CONFIG_ADV_INTERVAL_CHARACTERISTIC_UUID = new UUID(0x955A15280FE2F5AAl, 0xA09484B8D4F3E8ADl);
	private static final UUID CONFIG_LED_SETTINGS_CHARACTERISTIC_UUID = new UUID(0x955A15290FE2F5AAl, 0xA09484B8D4F3E8ADl);

	private BluetoothAdapter mAdapter;
	private BluetoothDevice mBluetoothDevice;
	private BluetoothGatt mBluetoothGatt;
	private BluetoothGattCharacteristic mUuidCharacteristic;
	private BluetoothGattCharacteristic mMajorMinorCharacteristic;
	private BluetoothGattCharacteristic mRssiCharacteristic;
	private BluetoothGattCharacteristic mManufacturerIdCharacteristic;
	private BluetoothGattCharacteristic mAdvIntervalCharacteristic;
	private BluetoothGattCharacteristic mLedSettingsCharacteristic;

	private Handler mHandler;

	private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
		@Override
		public void onConnectionStateChange(final BluetoothGatt gatt, final int status, final int newState) {
			if (status != BluetoothGatt.GATT_SUCCESS) {
				logw("Connection state change error: " + status);
				broadcastError(status);
				return;
			}

			if (newState == BluetoothProfile.STATE_CONNECTED) {
				setState(STATE_DISCOVERING_SERVICES);
				// Attempts to discover services after successful connection.
				gatt.discoverServices();
			} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
				setState(STATE_DISCONNECTED);
				refreshDeviceCache(gatt);
				gatt.close();
				mBluetoothGatt = null;
				stopSelf();
			}
		}

		@Override
		public void onServicesDiscovered(final BluetoothGatt gatt, final int status) {
			if (status != BluetoothGatt.GATT_SUCCESS) {
				logw("Service discovery error: " + status);
				broadcastError(status);
				return;
			}

			// We have successfully connected
			setState(STATE_CONNECTED);

			// Search for config service
			final BluetoothGattService configService = gatt.getService(CONFIG_SERVICE_UUID);
			if (configService == null) {
				// Config service is not present
				broadcastError(ERROR_UNSUPPORTED_DEVICE);
				setState(STATE_DISCONNECTING);
				gatt.disconnect();
				return;
			}

			mUuidCharacteristic = configService.getCharacteristic(CONFIG_UUID_CHARACTERISTIC_UUID);
			mMajorMinorCharacteristic = configService.getCharacteristic(CONFIG_MAJOR_MINOR_CHARACTERISTIC_UUID);
			mRssiCharacteristic = configService.getCharacteristic(CONFIG_RSSI_CHARACTERISTIC_UUID);
			mManufacturerIdCharacteristic = configService.getCharacteristic(CONFIG_MANUFACTURER_ID_CHARACTERISTIC_UUID);
			mAdvIntervalCharacteristic = configService.getCharacteristic(CONFIG_ADV_INTERVAL_CHARACTERISTIC_UUID);
			mLedSettingsCharacteristic = configService.getCharacteristic(CONFIG_LED_SETTINGS_CHARACTERISTIC_UUID);

			if (mUuidCharacteristic != null || mMajorMinorCharacteristic != null || mRssiCharacteristic != null)
				broadcastOperationCompleted(mManufacturerIdCharacteristic != null || mAdvIntervalCharacteristic != null || mLedSettingsCharacteristic != null);

			if (mUuidCharacteristic == null && mMajorMinorCharacteristic == null && mRssiCharacteristic == null) {
				// Config characteristics is not present
				broadcastError(ERROR_UNSUPPORTED_DEVICE);
				setState(STATE_DISCONNECTING);
				gatt.disconnect();
			}
		}

		@Override
		public void onCharacteristicWrite(final BluetoothGatt gatt, final BluetoothGattCharacteristic characteristic, final int status) {
			if (status != BluetoothGatt.GATT_SUCCESS) {
				logw("Characteristic write error: " + status);
				broadcastError(status);
				return;
			}

			if (CONFIG_UUID_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final UUID uuid = decodeBeaconUUID(characteristic);
				broadcastUuid(uuid);
			} else if (CONFIG_MAJOR_MINOR_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int major = decodeUInt16(characteristic, 0);
				final int minor = decodeUInt16(characteristic, 2);
				broadcastMajorAndMinor(major, minor);
			} else if (CONFIG_RSSI_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int rssi = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_SINT8, 0);
				broadcastRssi(rssi);
			} else if (CONFIG_MANUFACTURER_ID_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int id = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT16, 0);
				broadcastManufacturerId(id);
			} else if (CONFIG_ADV_INTERVAL_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int interval = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT16, 0);
				broadcastAdvInterval(interval);
			} else if (CONFIG_LED_SETTINGS_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final boolean on = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0) == 1;
				broadcastLedStatus(on);
			}
		}

		@Override
		public void onCharacteristicRead(final BluetoothGatt gatt, final BluetoothGattCharacteristic characteristic, final int status) {
			if (status != BluetoothGatt.GATT_SUCCESS) {
				logw("Characteristic read error: " + status);
				broadcastError(status);
				return;
			}

			if (CONFIG_UUID_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final UUID uuid = decodeBeaconUUID(characteristic);
				broadcastUuid(uuid);
				if (mMajorMinorCharacteristic != null && mMajorMinorCharacteristic.getValue() == null)
					gatt.readCharacteristic(mMajorMinorCharacteristic);
			} else if (CONFIG_MAJOR_MINOR_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int major = decodeUInt16(characteristic, 0);
				final int minor = decodeUInt16(characteristic, 2);
				broadcastMajorAndMinor(major, minor);
				if (mRssiCharacteristic != null && mRssiCharacteristic.getValue() == null)
					gatt.readCharacteristic(mRssiCharacteristic);
			} else if (CONFIG_RSSI_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int rssi = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_SINT8, 0);
				broadcastRssi(rssi);
				if (mManufacturerIdCharacteristic != null && mManufacturerIdCharacteristic.getValue() == null)
					gatt.readCharacteristic(mManufacturerIdCharacteristic);
			} else if (CONFIG_MANUFACTURER_ID_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int id = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT16, 0);
				broadcastManufacturerId(id);
				if (mAdvIntervalCharacteristic != null && mAdvIntervalCharacteristic.getValue() == null)
					gatt.readCharacteristic(mAdvIntervalCharacteristic);
			} else if (CONFIG_ADV_INTERVAL_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final int interval = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT16, 0);
				broadcastAdvInterval(interval);
				if (mLedSettingsCharacteristic != null && mLedSettingsCharacteristic.getValue() == null)
					gatt.readCharacteristic(mLedSettingsCharacteristic);
			} else if (CONFIG_LED_SETTINGS_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
				final boolean on = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0) == 1;
				broadcastLedStatus(on);
			}
		}
	};

	public class ServiceBinder extends Binder {
		/**
		 * Connects to the service. The bluetooth device must have been passed during binding to the service in {@link UpdateService#EXTRA_DATA} field.
		 * 
		 * @return <code>true</code> if connection process has been initiated
		 */
		public boolean connect() {
			if (mAdapter == null) {
				logw("BluetoothAdapter not initialized or unspecified address.");
				return false;
			}

			if (mBluetoothDevice == null) {
				logw("Target device not specified. Start service with the BluetoothDevice set in EXTRA_DATA field.");
				return false;
			}

			// the device may be already connected 
			if (mConnectionState == STATE_CONNECTED) {
				return true;
			}

			setState(STATE_CONNECTING);
			mBluetoothGatt = mBluetoothDevice.connectGatt(UpdateService.this, false, mGattCallback);
			return true;
		}

		/**
		 * Disconnects from the device and closes the Bluetooth GATT object afterwards.
		 */
		public void disconnectAndClose() {
			// This sometimes happen when called from UpdateService.ACTION_GATT_ERROR event receiver in UpdateFragment.
			if (mBluetoothGatt == null)
				return;

			setState(STATE_DISCONNECTING);
			mBluetoothGatt.disconnect();

			// Sometimes the connection gets error 129 or 133. Calling disconnect() method does not really disconnect... sometimes the connection is already broken.
			// Here we have a security check that notifies UI about disconnection even if onConnectionStateChange(...) has not been called. 
			mHandler.postDelayed(new Runnable() {
				@Override
				public void run() {
					if (mConnectionState == STATE_DISCONNECTING)
						mGattCallback.onConnectionStateChange(mBluetoothGatt, BluetoothGatt.GATT_SUCCESS, BluetoothProfile.STATE_DISCONNECTED);
				}
			}, 1500);
		}

		/**
		 * Reads all the values from the device, one by one.
		 * 
		 * @return <code>true</code> if at least one required characteristic has been found on the beacon.
		 */
		public boolean read() {
			if (mBluetoothGatt == null)
				return false;

			if (mUuidCharacteristic != null) {
				mBluetoothGatt.readCharacteristic(mUuidCharacteristic);
				return true;
			} else if (mMajorMinorCharacteristic != null) {
				mBluetoothGatt.readCharacteristic(mMajorMinorCharacteristic);
				return true;
			} else if (mRssiCharacteristic != null) {
				mBluetoothGatt.readCharacteristic(mRssiCharacteristic);
				return true;
			}
			return false;
		}

		/**
		 * Overwrites the beacon service UUID.
		 * 
		 * @param uuid
		 *            the new UUID
		 * @return <code>true</code> if altering UUID is supported (required characteristic exists)
		 */
		public boolean setBeaconUuid(final UUID uuid) {
			if (mUuidCharacteristic == null || uuid == null)
				return false;

			final byte[] data = new byte[16];
			for (int i = 0; i < 8; ++i)
				data[i] = (byte) ((uuid.getMostSignificantBits() >>> (56 - i * 8)) & 0xFF);
			for (int i = 8; i < 16; ++i)
				data[i] = (byte) ((uuid.getLeastSignificantBits() >>> (56 - i * 8)) & 0xFF);
			mUuidCharacteristic.setValue(data);
			mBluetoothGatt.writeCharacteristic(mUuidCharacteristic);
			return true;
		}

		/**
		 * Returns the current UUID value. This reads the value from the local cache. The {@link #read()} method must be invoked before to read the current value from the device.
		 * 
		 * @return the beacon service UUID
		 */
		public UUID getBeaconUuid() {
			final BluetoothGattCharacteristic characteristic = mUuidCharacteristic;
			if (characteristic != null) {
				final byte[] data = characteristic.getValue();
				if (data == null || data.length != 16)
					return null;
				return decodeBeaconUUID(characteristic);
			}
			return null;
		}

		/**
		 * Overwrites the beacon major and minor numbers.
		 * 
		 * @param major
		 *            the major number (0-65535)
		 * @param minor
		 *            the minor number (0-65535)
		 * @return <code>true</code> if altering major and minor is supported (required characteristic exists)
		 */
		public boolean setMajorAndMinor(final int major, final int minor) {
			if (mMajorMinorCharacteristic == null)
				return false;

			if (major < 0 || major > 0xFFFF)
				return false;

			if (minor < 0 || minor > 0xFFFF)
				return false;

			final int majorInverted = (major & 0xFF) << 8 | ((major >> 8) & 0xFF);
			final int minorInverted = (minor & 0xFF) << 8 | ((minor >> 8) & 0xFF);
			mMajorMinorCharacteristic.setValue(majorInverted, BluetoothGattCharacteristic.FORMAT_UINT16, 0);
			mMajorMinorCharacteristic.setValue(minorInverted, BluetoothGattCharacteristic.FORMAT_UINT16, 2);
			mBluetoothGatt.writeCharacteristic(mMajorMinorCharacteristic);
			return true;
		}

		/**
		 * Returns the pair of current Major and Minor values. This reads the value from the local cache. The {@link #read()} method must be invoked before to read the current value from the device.
		 * 
		 * @return the pair where the first value is the major number and the second is the minor value
		 */
		public Pair<Integer, Integer> getMajorAndMinor() {
			final BluetoothGattCharacteristic characteristic = mMajorMinorCharacteristic;
			if (characteristic != null) {
				final byte[] data = characteristic.getValue();
				if (data == null || data.length != 4)
					return null;
				final int major = decodeUInt16(characteristic, 0);
				final int minor = decodeUInt16(characteristic, 2);
				return new Pair<>(major, minor);
			}
			return null;
		}

		/**
		 * Overwrites the beacon calibration RSSI value.
		 * 
		 * @param rssi
		 *            the RSSI value calculated at 1m distance from the beacon.
		 * @return <code>true</code> if altering major and minor is supported (required characteristic exists)
		 */
		public boolean setCalibratedRssi(final int rssi) {
			if (mRssiCharacteristic == null)
				return false;

			mRssiCharacteristic.setValue(rssi, BluetoothGattCharacteristic.FORMAT_SINT8, 0);
			mBluetoothGatt.writeCharacteristic(mRssiCharacteristic);
			return true;
		}

		/**
		 * Obtains the cached value of the RSSI characteristic. If the value has not been obtained yet using {@link #read()}, or the characteristic has not been found on the beacon, <code>null</code>
		 * is returned.
		 * 
		 * @return the RSSI value or <code>null</code>
		 */
		public Integer getCalibratedRssi() {
			final BluetoothGattCharacteristic characteristic = mRssiCharacteristic;
			if (characteristic != null) {
				final byte[] data = characteristic.getValue();
				if (data == null || data.length < 1)
					return null;
				return characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_SINT8, 0);
			}
			return null;
		}

		/**
		 * Overwrites the beacon manufacturer ID (Company Identifier) value.
		 * 
		 * @param id
		 *            the new manufacturer ID. A beacon will advertise with this ID in its manufacturer data.
		 * @return <code>true</code> if altering manufacturer id is supported (required characteristic exists)
		 */
		public boolean setManufacturerId(final int id) {
			if (mManufacturerIdCharacteristic == null)
				return false;

			mManufacturerIdCharacteristic.setValue(id, BluetoothGattCharacteristic.FORMAT_UINT16, 0);
			mBluetoothGatt.writeCharacteristic(mManufacturerIdCharacteristic);
			return true;
		}

		/**
		 * Obtains the cached value of the Manufacturer ID characteristic. If the value has not been obtained yet using {@link #read()}, or the characteristic has not been found on the beacon,
		 * <code>null</code> is returned.
		 * 
		 * @return the Manufacturer ID or <code>null</code>
		 */
		public Integer getManufacturerId() {
			final BluetoothGattCharacteristic characteristic = mManufacturerIdCharacteristic;
			if (characteristic != null) {
				final byte[] data = characteristic.getValue();
				if (data == null || data.length < 2)
					return null;
				return characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT16, 0);
			}
			return null;
		}

		/**
		 * Overwrites the beacon advertising interval value. Values <100 - 10240> are valid.
		 * 
		 * @param interval
		 *            the new beacon advertising interval, 760 ms by default
		 * @return <code>true</code> if altering advertising interval is supported (required characteristic exists) and given value is valid, <code>false</code> if not
		 */
		public boolean setAdvInterval(final int interval) {
			if (mAdvIntervalCharacteristic == null)
				return false;

			if (interval < 100 || interval > 10240)
				return false;

			mAdvIntervalCharacteristic.setValue(interval, BluetoothGattCharacteristic.FORMAT_UINT16, 0);
			mBluetoothGatt.writeCharacteristic(mAdvIntervalCharacteristic);
			return true;
		}

		/**
		 * Obtains the cached value of the advertising interval characteristic. If the value has not been obtained yet using {@link #read()}, or the characteristic has not been found on the beacon,
		 * <code>null</code> is returned.
		 * 
		 * @return the advertising interval or <code>null</code>
		 */
		public Integer getAdvInterval() {
			final BluetoothGattCharacteristic characteristic = mAdvIntervalCharacteristic;
			if (characteristic != null) {
				final byte[] data = characteristic.getValue();
				if (data == null || data.length < 2)
					return null;
				return characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT16, 0);
			}
			return null;
		}

		/**
		 * Returns <code>true</code> if the beacon supports the advanced configuration.
		 */
		public boolean isAdvancedSupported() {
			return mManufacturerIdCharacteristic != null || mAdvIntervalCharacteristic != null || mLedSettingsCharacteristic != null;
		}

		/**
		 * Enables or disables the LED on the beacon. Disabling the LED will extend the battery life.
		 * 
		 * @param on
		 *            the new LED status
		 * @return <code>true</code> if altering LED status is supported (required characteristic exists)
		 */
		public boolean setLedStatus(final boolean on) {
			if (mLedSettingsCharacteristic == null)
				return false;

			mLedSettingsCharacteristic.setValue(on ? 1 : 0, BluetoothGattCharacteristic.FORMAT_UINT8, 0);
			mBluetoothGatt.writeCharacteristic(mLedSettingsCharacteristic);
			return true;
		}

		/**
		 * Obtains the cached value of the LED status characteristic. If the value has not been obtained yet using {@link #read()}, or the characteristic has not been found on the beacon,
		 * <code>null</code> is returned.
		 * 
		 * @return the advertising interval or <code>null</code>
		 */
		public Boolean getLedStatus() {
			final BluetoothGattCharacteristic characteristic = mLedSettingsCharacteristic;
			if (characteristic != null) {
				final byte[] data = characteristic.getValue();
				if (data == null || data.length < 1)
					return null;
				return characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0) == 1;
			}
			return null;
		}

		public int getState() {
			return mConnectionState;
		}
	}

	@Override
	public void onCreate() {
		super.onCreate();

		initialize();
		mHandler = new Handler();
		mConnectionState = STATE_DISCONNECTED;
	}

	@Override
	public void onDestroy() {
		super.onDestroy();

		if (mBluetoothGatt != null)
			mBluetoothGatt.disconnect();
		mHandler = null;
		mBluetoothDevice = null;
	}

	@Override
	public IBinder onBind(final Intent intent) {
		return new ServiceBinder();
	}

	@Override
	public boolean onUnbind(final Intent intent) {
		// We want to allow rebinding
		return true;
	}

	@Override
	public int onStartCommand(final Intent intent, final int flags, final int startId) {
		mBluetoothDevice = intent.getParcelableExtra(EXTRA_DATA);
		return START_NOT_STICKY;
	}

	/**
	 * Initializes a reference to the local Bluetooth adapter.
	 */
	private void initialize() {
		final BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(BLUETOOTH_SERVICE);
		mAdapter = bluetoothManager.getAdapter();
	}

	private void setState(final int state) {
		mConnectionState = state;
		final Intent intent = new Intent(ACTION_STATE_CHANGED);
		intent.putExtra(EXTRA_DATA, state);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastUuid(final UUID uuid) {
		final Intent intent = new Intent(ACTION_UUID_READY);
		intent.putExtra(EXTRA_DATA, new ParcelUuid(uuid));
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastMajorAndMinor(final int major, final int minor) {
		final Intent intent = new Intent(ACTION_MAJOR_MINOR_READY);
		intent.putExtra(EXTRA_MAJOR, major);
		intent.putExtra(EXTRA_MINOR, minor);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastRssi(final int rssi) {
		final Intent intent = new Intent(ACTION_RSSI_READY);
		intent.putExtra(EXTRA_DATA, rssi);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastManufacturerId(final int id) {
		final Intent intent = new Intent(ACTION_MANUFACTURER_ID_READY);
		intent.putExtra(EXTRA_DATA, id);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastAdvInterval(final int interval) {
		final Intent intent = new Intent(ACTION_ADV_INTERVAL_READY);
		intent.putExtra(EXTRA_DATA, interval);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastLedStatus(final boolean status) {
		final Intent intent = new Intent(ACTION_LED_STATUS_READY);
		intent.putExtra(EXTRA_DATA, status);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastOperationCompleted(final boolean advanced) {
		final Intent intent = new Intent(ACTION_DONE);
		intent.putExtra(EXTRA_DATA, advanced);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	private void broadcastError(final int error) {
		final Intent intent = new Intent(ACTION_GATT_ERROR);
		intent.putExtra(EXTRA_DATA, error);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}

	/**
	 * Clears the device cache.
	 * <p>
	 * CAUTION:<br />
	 * It is very unsafe to call the refresh() method. First of all it's hidden so it may be removed in the future release of Android. We do it because Nordic Beacon may advertise as a beacon, as
	 * Beacon Config or DFU. Android does not clear cache then device is disconnected unless manually restarted Bluetooth Adapter. To do this in the code we need to call
	 * {@link BluetoothGatt#refresh()} method. However is may cause a lot of troubles. Ideally it should be called before connection attempt but we get 'gatt' object by calling connectGatt method so
	 * when the connection already has been started. Calling refresh() afterwards causes errors 129 and 133 to pop up from time to time when refresh takes place actually during service discovery. It
	 * seems to be asynchronous method. Therefore we are refreshing the device after disconnecting from it, before closing gatt. Sometimes you may obtain services from cache, not the actual values so
	 * reconnection is required.
	 * 
	 * @param gatt
	 *            the Bluetooth GATT object to refresh.
	 */
	private boolean refreshDeviceCache(final BluetoothGatt gatt) {
		/*
		 * There is a refresh() method in BluetoothGatt class but for now it's hidden. We will call it using reflections.
		 */
		try {
			final Method refresh = gatt.getClass().getMethod("refresh");
			if (refresh != null) {
				return (Boolean) refresh.invoke(gatt);
			}
		} catch (final Exception e) {
			loge("An exception occurred while refreshing device");
		}
		return false;
	}

	private void loge(final String message) {
		if (BuildConfig.DEBUG)
			Log.e(TAG, message);
	}

	private void logw(final String message) {
		if (BuildConfig.DEBUG)
			Log.w(TAG, message);
	}

	public static int decodeUInt16(final BluetoothGattCharacteristic characteristic, final int offset) {
		final byte[] data = characteristic.getValue();
		return (unsignedByteToInt(data[offset]) << 8) | unsignedByteToInt(data[offset + 1]);
	}

	public static UUID decodeBeaconUUID(final BluetoothGattCharacteristic characteristic) {
		final byte[] data = characteristic.getValue();
		final long mostSigBits = (unsignedByteToLong(data[0]) << 56) + (unsignedByteToLong(data[1]) << 48) + (unsignedByteToLong(data[2]) << 40) + (unsignedByteToLong(data[3]) << 32)
				+ (unsignedByteToLong(data[4]) << 24) + (unsignedByteToLong(data[5]) << 16) + (unsignedByteToLong(data[6]) << 8) + unsignedByteToLong(data[7]);
		final long leastSigBits = (unsignedByteToLong(data[8]) << 56) + (unsignedByteToLong(data[9]) << 48) + (unsignedByteToLong(data[10]) << 40) + (unsignedByteToLong(data[11]) << 32)
				+ (unsignedByteToLong(data[12]) << 24) + (unsignedByteToLong(data[13]) << 16) + (unsignedByteToLong(data[14]) << 8) + unsignedByteToLong(data[15]);
		return new UUID(mostSigBits, leastSigBits);
	}

	/**
	 * Convert a signed byte to an unsigned long.
	 */
	public static long unsignedByteToLong(byte b) {
		return b & 0xFF;
	}

	/**
	 * Convert a signed byte to an unsigned int.
	 */
	public static int unsignedByteToInt(int b) {
		return b & 0xFF;
	}
}