/*
 * Copyright 2015 Christian Basler
 *
 * 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 ch.dissem.apps.abit;

import android.graphics.*;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;

import ch.dissem.bitmessage.entity.BitmessageAddress;

/**
 * @author Christian Basler
 */
public class Identicon extends Drawable {
    private static final int SIZE = 9;
    private static final int CENTER_COLUMN = 5;

    private final Paint paint;
    private int color;
    private int background;
    private boolean[][] fields;

    public Identicon(BitmessageAddress input) {
        paint = new Paint();
        paint.setStyle(Paint.Style.FILL);
        paint.setAntiAlias(true);

        byte[] hash = input.getRipe();

        fields = new boolean[SIZE][SIZE];
        color = Color.HSVToColor(new float[]{
            Math.abs(hash[0] * hash[1] + hash[2]) % 360,
            0.8f,
            1.0f
        });
        background = Color.HSVToColor(new float[]{
            Math.abs(hash[1] * hash[2] + hash[0]) % 360,
            0.8f,
            1.0f
        });

        for (int row = 0; row < SIZE; row++) {
            for (int column = 0; column < SIZE; column++) {
                fields[row][column] = hash[(row * (column < CENTER_COLUMN ? column : SIZE -
                    column - 1)) % hash.length] >= 0;
            }
        }
    }

    @Override
    public void draw(@NonNull Canvas canvas) {
        float x, y;
        float width = canvas.getWidth();
        float height = canvas.getHeight();
        float cellWidth = width / (float) SIZE;
        float cellHeight = height / (float) SIZE;
        paint.setColor(background);
        canvas.drawCircle(width / 2, height / 2, width / 2, paint);
        paint.setColor(color);
        for (int row = 0; row < SIZE; row++) {
            for (int column = 0; column < SIZE; column++) {
                if (fields[row][column]) {
                    x = cellWidth * column;
                    y = cellHeight * row;

                    canvas.drawCircle(x + cellWidth / 2, y + cellHeight / 2, cellHeight / 2, paint);
                }
            }
        }
    }

    @Override
    public void setAlpha(int alpha) {
        paint.setAlpha(alpha);
    }

    @Override
    public void setColorFilter(ColorFilter cf) {
        paint.setColorFilter(cf);
    }

    @Override
    public int getOpacity() {
        return PixelFormat.TRANSPARENT;
    }
}