/*
 * Author: Andrei Vasiliu <andrei.vasiliu@intel.com>
 * Copyright (c) 2016 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package tinyb;

import java.util.*;
import java.time.Duration;

public class BluetoothManager
{
    private long nativeInstance;
    private static BluetoothManager inst;

    /**
     * The thread to watch for nearby devices
     */
    private Thread nearbyThread = null;
    
    static {
        try {
            System.loadLibrary("tinyb");
            System.loadLibrary("javatinyb");
        } catch (UnsatisfiedLinkError e) {
            System.err.println("Native code library failed to load.\n" + e);
        }
    }

    private native static String getNativeAPIVersion();

    public native BluetoothType getBluetoothType();

    private native BluetoothObject find(int type, String name, String identifier, BluetoothObject parent, long milliseconds);

    /** Find a BluetoothObject of a type matching type. If parameters name,
      * identifier and parent are not null, the returned object will have to
      * match them.
      * It will first check for existing objects. It will not turn on discovery
      * or connect to devices.
      * @parameter type specify the type of the object you are
      * waiting for, NONE means anything.
      * @parameter name optionally specify the name of the object you are
      * waiting for (for Adapter or Device)
      * @parameter identifier optionally specify the identifier of the object you are
      * waiting for (UUID for GattService, GattCharacteristic or GattDescriptor, address
      * for Adapter or Device)
      * @parameter parent optionally specify the parent of the object you are
      * waiting for
      * @parameter timeout the function will return after timeout time, a
      * value of zero means wait forever. If object is not found during this time null will be returned.
      * @return An object matching the name, identifier, parent or null if not found before
      * timeout expires or event is canceled.
      */
    public BluetoothObject find(BluetoothType type, String name, String identifier, BluetoothObject parent, Duration timeout) {
        return find(type.ordinal(), name, identifier, parent, timeout.toNanos() / 1000000);
    }


    /** Find a BluetoothObject of a type matching type. If parameters name,
      * identifier and parent are not null, the returned object will have to
      * match them.
      * It will first check for existing objects. It will not turn on discovery
      * or connect to devices.
      * @parameter type specify the type of the object you are
      * waiting for, NONE means anything.
      * @parameter name optionally specify the name of the object you are
      * waiting for (for Adapter or Device)
      * @parameter identifier optionally specify the identifier of the object you are
      * waiting for (UUID for GattService, GattCharacteristic or GattDescriptor, address
      * for Adapter or Device)
      * @parameter parent optionally specify the parent of the object you are
      * waiting for
      * @return An object matching the name, identifier and parent.
      */
    public BluetoothObject find(BluetoothType type, String name, String identifier, BluetoothObject parent) {
        return find(type, name, identifier, parent, Duration.ZERO);
    }

    /** Find a BluetoothObject of type T. If parameters name, identifier and
      * parent are not null, the returned object will have to match them.
      * It will first check for existing objects. It will not turn on discovery
      * or connect to devices.
      * @parameter name optionally specify the name of the object you are
      * waiting for (for Adapter or Device)
      * @parameter identifier optionally specify the identifier of the object you are
      * waiting for (UUID for GattService, GattCharacteristic or GattDescriptor, address
      * for Adapter or Device)
      * @parameter parent optionally specify the parent of the object you are
      * waiting for
      * @parameter timeout the function will return after timeout time, a
      * value of zero means wait forever. If object is not found during this time null will be returned.
      * @return An object matching the name, identifier, parent or null if not found before
      * timeout expires or event is canceled.
      */
    public <T extends BluetoothObject>  T find(String name, String identifier, BluetoothObject parent, Duration timeout) {
        return (T) find(T.class_type().ordinal(), name, identifier, parent, timeout.toNanos() / 1000000);
    }

    /** Find a BluetoothObject of type T. If parameters name, identifier and
      * parent are not null, the returned object will have to match them.
      * It will first check for existing objects. It will not turn on discovery
      * or connect to devices.
      * @parameter name optionally specify the name of the object you are
      * waiting for (for Adapter or Device)
      * @parameter identifier optionally specify the identifier of the object you are
      * waiting for (UUID for GattService, GattCharacteristic or GattDescriptor, address
      * for Adapter or Device)
      * @parameter parent optionally specify the parent of the object you are
      * waiting for
      * @return An object matching the name, identifier and parent.
      */
    public <T extends BluetoothObject>  T find(String name, String identifier, BluetoothObject parent) {
        return (T) find(name, identifier, parent, Duration.ZERO);
    }

    /** Return a BluetoothObject of a type matching type. If parameters name,
      * identifier and parent are not null, the returned object will have to
      * match them. Only objects which are already in the system will be returned.
      * @parameter type specify the type of the object you are
      * waiting for, NONE means anything.
      * @parameter name optionally specify the name of the object you are
      * waiting for (for Adapter or Device)
      * @parameter identifier optionally specify the identifier of the object you are
      * waiting for (UUID for GattService, GattCharacteristic or GattDescriptor, address
      * for Adapter or Device)
      * @parameter parent optionally specify the parent of the object you are
      * waiting for
      * @return An object matching the name, identifier, parent or null if not found.
      */
    public BluetoothObject getObject(BluetoothType type, String name,
                                String identifier, BluetoothObject parent) {
        return getObject(type.ordinal(), name, identifier, parent);
    }
    private native BluetoothObject getObject(int type, String name,
                                    String identifier, BluetoothObject parent);

    /** Return a List of BluetoothObject of a type matching type. If parameters name,
      * identifier and parent are not null, the returned object will have to
      * match them. Only objects which are already in the system will be returned.
      * @parameter type specify the type of the object you are
      * waiting for, NONE means anything.
      * @parameter name optionally specify the name of the object you are
      * waiting for (for Adapter or Device)
      * @parameter identifier optionally specify the identifier of the object you are
      * waiting for (UUID for GattService, GattCharacteristic or GattDescriptor, address
      * for Adapter or Device)
      * @parameter parent optionally specify the parent of the object you are
      * waiting for
      * @return A vector of object matching the name, identifier, parent.
      */
    public List<BluetoothObject> getObjects(BluetoothType type, String name,
                                    String identifier, BluetoothObject parent) {
        return getObjects(type.ordinal(), name, identifier, parent);
    }
    private native List<BluetoothObject> getObjects(int type, String name,
                                    String identifier, BluetoothObject parent);

    /** Returns a list of BluetoothAdapters available in the system
      * @return A list of BluetoothAdapters available in the system
      */
    public native List<BluetoothAdapter> getAdapters();

    /** Returns a list of discovered BluetoothDevices
      * @return A list of discovered BluetoothDevices
      */
    public native List<BluetoothDevice> getDevices();

    /** Returns a list of available BluetoothGattServices
      * @return A list of available BluetoothGattServices
      */
    public native List<BluetoothGattService> getServices();

    /** Sets a default adapter to use for discovery.
      * @return TRUE if the device was set
      */
    public native boolean setDefaultAdapter(BluetoothAdapter adapter);

    /** Turns on device discovery on the default adapter if it is disabled.
      * @return TRUE if discovery was successfully enabled
      */
    public native boolean startDiscovery() throws BluetoothException;

    /** Turns off device discovery on the default adapter if it is enabled.
      * @return TRUE if discovery was successfully disabled
      */
    public native boolean stopDiscovery() throws BluetoothException;

    /** Returns if the discovers is running or not.
      * @return TRUE if discovery is running
      */
    public native boolean getDiscovering() throws BluetoothException;  

    /**
     * When called, each new device found will fire an event to the passed
     * listener<p>
     *
     * This method will create a new thread to handle the discovery process
     * which is a simple polling of the current list (getDevices)
     * <p>
     *
     * The thread is stopped when the nearbyStopDiscovery is called<p>
     *
     * @param listener
     * @param pollingRate The polling rate is miliseconds (1000 = 1s)
     * @param onlyManufacturerFilled If true, then only if the manufacturer data is filled, the event will be fired
     */
    public void startNearbyDiscovery(final BluetoothDeviceDiscoveryListener listener, final int pollingRate, final boolean onlyManufacturerFilled) {
        //--- If alreay started, does nothing
        if ((nearbyThread != null) && nearbyThread.isAlive()) return;
        
        //--- Remove all devices to have a clean start
        getAdapters().get(0).removeDevices();
        
        //--- Start the bluez discovery
        startDiscovery();

        //--- Thread to poll the devices list
        nearbyThread = new Thread() {
            public void run() {
                //--- The key is the address
                HashMap<String, BluetoothDevice> discovered = new HashMap<String, BluetoothDevice>();
                try {
                    while (Thread.interrupted() == false) {
                        List<BluetoothDevice> list = getDevices();
                        for (BluetoothDevice d:list) {
                            if (!discovered.containsKey(d.getAddress())) {
                                if (onlyManufacturerFilled) {
                                    if (!d.getManufacturerData().isEmpty()) {
                                        discovered.put(d.getAddress(), d);
                                        if (listener != null) listener.bluetoothDeviceDiscovered(d);
                                    }
                                    
                                } else {
                                    discovered.put(d.getAddress(), d);
                                    if (listener != null) listener.bluetoothDeviceDiscovered(d);
                                }
                            }
                        }
                        //--- Polling rate of 1 second
                        sleep(pollingRate);
                    }

                } catch (InterruptedException ex) {
                    //--- Stopped by user or jvm
                }
                stopDiscovery();
                
            }
        };
        nearbyThread.start();

    }

    /**
     * Stop the nearby thread
     */
    public void stopNearbyDiscovery() {
        if ((nearbyThread != null) && nearbyThread.isAlive()) nearbyThread.interrupt();

    }

    /**
     * Interface to implement to receive the device discovery event
     */
    public interface BluetoothDeviceDiscoveryListener {

        public void bluetoothDeviceDiscovered(BluetoothDevice device);
    }
    
    private native void init() throws BluetoothException;
    private native void delete();
    private BluetoothManager()
    {
        init();
    }

    /** Returns an instance of BluetoothManager, to be used instead of constructor.
      * @return An initialized BluetoothManager instance.
      */
    public static synchronized BluetoothManager getBluetoothManager() throws RuntimeException, BluetoothException
    {
        if (inst == null)
        {
            String nativeAPIVersion = getNativeAPIVersion();
            String APIVersion = BluetoothManager.class.getPackage().getSpecificationVersion();
            if (APIVersion != null && APIVersion.equals(nativeAPIVersion) == false) {
                String[] nativeAPIVersionCode = nativeAPIVersion.split("\\D");
                String[] APIVersionCode = APIVersion.split("\\D");
                if (APIVersionCode[0].equals(nativeAPIVersionCode[0]) == false) {
                    if (Integer.valueOf(APIVersionCode[0]) < Integer.valueOf(nativeAPIVersionCode[0]))
                        throw new RuntimeException("Java library is out of date. Please update the Java library.");
                    else throw new RuntimeException("Native library is out of date. Please update the native library.");
                }
                else if (APIVersionCode[0].equals("0") == true) {
                    if (Integer.valueOf(APIVersionCode[1]) < Integer.valueOf(nativeAPIVersionCode[1]))
                        throw new RuntimeException("Java library is out of date. Please update the Java library.");
                    else throw new RuntimeException("Native library is out of date. Please update the native library.");
                }
                else if (Integer.valueOf(APIVersionCode[1]) < Integer.valueOf(nativeAPIVersionCode[1]))
                    System.err.println("Java library is out of date. Please update the Java library.");
                else System.err.println("Native library is out of date. Please update the native library.");
            }
            inst = new BluetoothManager();
            inst.init();
        }
        return inst;
    }

    protected void finalize()
    {
        delete();
    }
}