import org.opencv.android.Utils;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;
import org.opencv.highgui.VideoCapture;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class CameraViewOpenCV extends SurfaceView implements SurfaceHolder.Callback, Runnable {
	private static final String TAG = "Sample::SurfaceView";

	private SurfaceHolder       mHolder;
	private VideoCapture        mCamera;
	private Mat mRgba;

	public CameraViewOpenCV(Context context) {
		super(context);
		mHolder = getHolder();
		mHolder.addCallback(this);
	}

	public void surfaceChanged(SurfaceHolder _holder, int format, int width, int height) {
		Log.i(TAG, "surfaceCreated");

		if (mCamera != null && mCamera.isOpened()) {
			mCamera.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, 640);
			mCamera.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, 480);
		}
	}

	public void surfaceCreated(SurfaceHolder holder) {
		Log.i(TAG, "surfaceCreated");

		mRgba  = new Mat();
		mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
		if(mCamera.isOpened()){
			(new Thread(this)).start();
		} else {
			mRgba.release();
			mCamera.release();
			mCamera = null;
			Log.e(TAG, "Failed to open native camera");
		}


	}

	public void surfaceDestroyed(SurfaceHolder holder) {
		Log.i(TAG, "surfaceDestroyed");
		if (mCamera != null) {
			mCamera.release();
			mCamera = null;
		}
	}

	public double timet(double l){
		return ((Core.getTickCount() - l)/Core.getTickFrequency()) * 1000;
	}

	public void run() {
		int i = 0;
		double d, total = 0;
		while (true) {
			d = Core.getTickCount();
			Bitmap bmp = null;

			if (mCamera == null)
				break;
			if (!mCamera.grab()) {
				Log.e(TAG, "mCamera.grab() failed");
				break;
			}

			mCamera.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA);
			bmp = Bitmap.createBitmap(mRgba.cols(), mRgba.rows(), Bitmap.Config.ARGB_8888);
			Utils.matToBitmap(mRgba, bmp);

			if (bmp != null) {
				Canvas canvas = mHolder.lockCanvas();
				if (canvas != null) {
					canvas.drawBitmap(bmp, (canvas.getWidth() - bmp.getWidth()) / 2, (canvas.getHeight() - bmp.getHeight()) / 2, null);
					mHolder.unlockCanvasAndPost(canvas);
				}
				bmp.recycle();	
				
				// measure frame rate
				total += timet(d);
				if((i++ % 100) == 0){
					Log.w("Opencv Camera", "Average frame time: " + total/100 + "ms" + " ##Frame Rate:" + (100000/(total)) + "fps");
					total = 0;
				}
			}
		}
	}
}