//package indoor.java;
package android.net.wifi;

import android.app.Activity;
import android.util.Log;
import android.content.Context;

import java.lang.System;

import java.util.List;
import java.util.ArrayList;

import android.net.wifi.ScanResult;
import android.net.wifi.rtt.RangingRequest;
import android.net.wifi.rtt.RangingResult;
import android.net.wifi.rtt.RangingResultCallback;
import android.net.wifi.rtt.WifiRttManager;

import java.util.concurrent.Executor;
import android.net.MacAddress;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Array;

import indoor.java.MyActivity;
import java.io.ByteArrayOutputStream;


public class RTT {

	private static Activity act;
	private static WifiRttManager rttManager;
	private static Executor mainExecutor;
	private static Thread ftmThread;
	private static boolean ftmRunning;

    public static native void onRttData(int success, final byte[] mac, long timeMS, int distMM, int distStdDevMM, int numAttemptedMeas, int numSuccessfullMeas, int rssi);

	// result callback
	private static final RangingResultCallback callback = new RangingResultCallback() {
		@Override
		public void onRangingFailure(final int i) {
			//emitter.onError(new RuntimeException("The WiFi-Ranging failed with error code: " + i));
			Log.d("RTT", "onRangingFailure: " + i);
		}

	    @Override
		public void onRangingResults(final List<RangingResult> list) {
			//emitter.onSuccess(list);
			Log.d("RTT", "onRangingResults: " + list.size());

			for (final RangingResult res : list) {
                int success = 0;
                long timeStampInMS = 0;
                MacAddress mac = res.getMacAddress();
                int dist = 0;
                int stdDevDist = 0;
                int rssi = 0;
                int numAttemptedMeas = 0;
                int numSuccessfulMeas = 0;

                if (res.getStatus() == RangingResult.STATUS_SUCCESS) {
                    success = 1;
                    timeStampInMS = res.getRangingTimestampMillis();
                    dist = res.getDistanceMm();
                    stdDevDist = res.getDistanceStdDevMm();
                    rssi = res.getRssi();
                    numAttemptedMeas = res.getNumAttemptedMeasurements();
                    numSuccessfulMeas = res.getNumSuccessfulMeasurements();

                    //Log.d("RTT", mac.toString() + " " + dist + " " + stdDevDist + " " + rssi);
                } else {
                    //Log.d("RTT", mac.toString() + " FAILED");
                }

                onRttData(success, mac.toString().getBytes(), timeStampInMS, dist, stdDevDist, numAttemptedMeas, numSuccessfulMeas, rssi);
			}		
		}
	};

    public static int start() {

		if (ftmRunning)
		  return 0;

		Log.d("RTT", "start()");

		MyActivity act = MyActivity.act;
		rttManager = (WifiRttManager) act.getSystemService(Context.WIFI_RTT_RANGING_SERVICE);

		mainExecutor = act.getMainExecutor();

		final ArrayList<MacAddress> macs = new ArrayList<>();
        macs.add(MacAddress.fromString("38:de:ad:6d:77:25"));	// NUC 1
		macs.add(MacAddress.fromString("38:de:ad:6d:60:ff"));	// NUC 2
		macs.add(MacAddress.fromString("1c:1b:b5:ef:a2:9a"));	// NUC 3
		macs.add(MacAddress.fromString("1c:1b:b5:ec:d1:82"));   // NUC 4
        macs.add(MacAddress.fromString("d0:c6:37:bc:5c:41"));	// NUC 5

		ftmRunning = true;

		ftmThread = new Thread() {
			public void run() {
				while(ftmRunning) {
					try {
						Thread.sleep(200);
					} catch (Exception e) {;}
				    startRangingOnMacs(macs);
				}
			}
		};

		ftmThread.start();

	    return 1337;
	}

	public static int stop() {
		Log.d("RTT", "stop()");

		if (ftmRunning) {
			ftmRunning = false;
		}

		return 1337*2;
	}

    public static void startRangingOnMacs(final ArrayList<MacAddress> macs) {

		Log.d("RTT", "startRangingOnMac()");

		RangingRequest.Builder builder = new RangingRequest.Builder();

		for (final MacAddress mac : macs) {

			ScanResult sr = new ScanResult();
			sr.BSSID = mac.toString();
			sr.SSID = "tof_test";
			sr.frequency = 2447;
			sr.capabilities = "[ESS]";

			try {

				Class<?> clazz = Class.forName("android.net.wifi.ScanResult$InformationElement");
				Object[] ies = (Object[]) Array.newInstance(clazz, 1);

				Object ie = clazz.getDeclaredConstructor().newInstance();
				ies[0] = ie;

				Field f1 = sr.getClass().getDeclaredField("flags");
				f1.setAccessible(true);
				f1.set(sr, 2);

				Field f2 = sr.getClass().getDeclaredField("informationElements");
				f2.setAccessible(true);
				f2.set(sr, ies);

				builder.addAccessPoint(sr);

			} catch (final Exception e) {
			    e.printStackTrace();
			}

		}

	    Log.d("RTT", "startRanging() on " + macs.size());
		if (macs.size() == 0) {return;}

		// fire#
		final RangingRequest request = builder.build();
		rttManager.startRanging(request, mainExecutor, callback);

	}


    public static void startRangingOnScanResult(final List<ScanResult> scanResults) {

		Log.d("RTT", "startRangingOnScanResult()");

		// build the request
		int cnt = 0;
		RangingRequest.Builder builder = new RangingRequest.Builder();
		for (final ScanResult r : scanResults) {
			if (r.is80211mcResponder()) {
				Log.d("RTT", "- " + r.BSSID + " [supported]");
				builder.addAccessPoint(r);
				++cnt;
			} else {
			    Log.d("RTT", "- " + r.BSSID + " [NO!]");
			}
		}

	    Log.d("RTT", "startRanging on " + cnt + " devices");
		if (cnt == 0) {return;}

		// fire
		final RangingRequest request = builder.build();
		rttManager.startRanging(request, mainExecutor, callback);

	}

}