/*
 * FreeOTP
 *
 * Authors: Nathaniel McCallum <npmccallum@redhat.com>
 *
 * Copyright (C) 2013  Nathaniel McCallum, Red Hat
 *
 * 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 org.fedorahosted.freeotp;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

import android.hardware.Camera;
import android.hardware.Camera.PreviewCallback;
import android.os.AsyncTask;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.ChecksumException;
import com.google.zxing.FormatException;
import com.google.zxing.LuminanceSource;
import com.google.zxing.NotFoundException;
import com.google.zxing.PlanarYUVLuminanceSource;
import com.google.zxing.Reader;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.QRCodeReader;

public class DecodeAsyncTask extends AsyncTask<Void, Void, String> implements PreviewCallback {
	private static class Data {
		public byte[] data;
		Camera.Size size;
	}

	private final BlockingQueue<Data> mBlockingQueue;
	private final Reader mReader;

	public DecodeAsyncTask() {
		mBlockingQueue = new LinkedBlockingQueue<Data>(5);
		mReader = new QRCodeReader();
	}

	@Override
	protected String doInBackground(Void... args) {
		while (true) {
			try {
				Data data = mBlockingQueue.take();
				LuminanceSource ls = new PlanarYUVLuminanceSource(data.data,
									data.size.width, data.size.height, 0, 0,
									data.size.width, data.size.height, false);
				Result r = mReader.decode(new BinaryBitmap(new HybridBinarizer(ls)));
				return r.getText();
			} catch (InterruptedException e) {
				return null;
			} catch (NotFoundException e) {
			} catch (ChecksumException e) {
			} catch (FormatException e) {
			} catch (ArrayIndexOutOfBoundsException e) {
			} finally {
				mReader.reset();
			}
		}
	}

	@Override
	public void onPreviewFrame(byte[] data, Camera camera) {
		Data d = new Data();
		d.data = data;
		d.size = camera.getParameters().getPreviewSize();
		mBlockingQueue.offer(d);
	}
}