package de.thedevstack.conversationsplus.utils.ui;

import android.app.AlertDialog;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.graphics.Point;
import android.widget.ImageView;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import java.util.Hashtable;

import de.thedevstack.android.logcat.Logging;
import de.thedevstack.conversationsplus.Config;
import de.thedevstack.conversationsplus.ui.XmppActivity;

/**
 */
public final class QrCodeUtil {

    public static void showQrCode(XmppActivity activity) {
        String uri = activity.getShareableUri();
        if (uri != null) {
            Point size = new Point();
            activity.getWindowManager().getDefaultDisplay().getSize(size);
            final int width = (size.x < size.y ? size.x : size.y);

            Bitmap bitmap = QrCodeUtil.createQrCodeBitmap(uri, width);
            ImageView view = new ImageView(activity);
            view.setImageBitmap(bitmap);
            AlertDialog.Builder builder = new AlertDialog.Builder(activity);
            builder.setView(view);
            builder.create().show();
        }
    }

    public static Bitmap createQrCodeBitmap(String input, int size) {
        Logging.d(Config.LOGTAG,"qr code requested size: "+size);
        try {
            final QRCodeWriter QR_CODE_WRITER = new QRCodeWriter();
            final Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
            final BitMatrix result = QR_CODE_WRITER.encode(input, BarcodeFormat.QR_CODE, size, size, hints);
            final int width = result.getWidth();
            final int height = result.getHeight();
            final int[] pixels = new int[width * height];
            for (int y = 0; y < height; y++) {
                final int offset = y * width;
                for (int x = 0; x < width; x++) {
                    pixels[offset + x] = result.get(x, y) ? Color.BLACK : Color.TRANSPARENT;
                }
            }
            final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            Logging.d(Config.LOGTAG,"output size: "+width+"x"+height);
            bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
            return bitmap;
        } catch (final WriterException e) {
            return null;
        }
    }

    private QrCodeUtil() {}
}