/**
 * Copyright (c) 2015-2016, Michael Yang 杨福海 (fuhai999@gmail.com).
 * <p>
 * Licensed under the GNU Lesser General Public License (LGPL) ,Version 3.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.gnu.org/licenses/lgpl-3.0.txt
 * <p>
 * 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 com.terra.proxy.util;

import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;

/**
 * @author lanbase
 * @Description: TODO(图片处理)
 * @date 2017-6-23 15:07
 */
public class ImageUtils {

    public static int[] ratio(String src) throws IOException {
        BufferedImage bufferedImage = ImageIO.read(new File(src));
        int width = bufferedImage.getWidth();
        int height = bufferedImage.getHeight();
        return new int[]{width, height};
    }

    public static String ratioAsString(String src) throws IOException {
        File file = new File(src);
        if (!file.exists()) {
            return null;
        }
        BufferedImage bufferedImage = ImageIO.read(file);
        int width = bufferedImage.getWidth();
        int height = bufferedImage.getHeight();
        return String.format("%s x %s", width, height);
    }

    public static String scale(String src, int w, int h) throws IOException {
        int inserTo = src.lastIndexOf(".");
        String dest = src.substring(0, inserTo) + String.format("_%sx%s", w, h) + src.substring(inserTo, src.length());
        scale(src, dest, w, h);
        return dest;
    }

    /**
     * 图片大小压缩
     *
     * @param src
     * @throws IOException
     */
    public static void scale(String src) throws IOException {
        File file = new File(src);
        if (!file.exists()) {
            return;
        }
        BufferedImage bufferedImage = ImageIO.read(file);
        int w = bufferedImage.getWidth();
        int h = bufferedImage.getHeight();
        String srcSuffix = src.substring(src.lastIndexOf(".") + 1);
        Iterator<ImageReader> iterator = ImageIO.getImageReadersByFormatName(srcSuffix);
        ImageReader reader = (ImageReader) iterator.next();

        InputStream in = new FileInputStream(src);
        ImageInputStream iis = ImageIO.createImageInputStream(in);
        reader.setInput(iis);

        BufferedImage srcBuffered = readBuffereImage(reader, w, h);
        BufferedImage targetBuffered = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);

        Graphics graphics = targetBuffered.getGraphics();
        graphics.drawImage(srcBuffered.getScaledInstance(w, h, Image.SCALE_DEFAULT), 0, 0, null); // 绘制缩小后的图

        graphics.dispose();
        srcBuffered.flush();
        in.close();
        iis.close();

        ImageIO.write(targetBuffered, srcSuffix, file);
        targetBuffered.flush();
    }

    /**
     * 等比缩放，居中剪切
     *
     * @param src
     * @param dest
     * @param w
     * @param h
     * @throws IOException
     */
    public static void scale(String src, String dest, int w, int h) throws IOException {
        String srcSuffix = src.substring(src.lastIndexOf(".") + 1);
        Iterator<ImageReader> iterator = ImageIO.getImageReadersByFormatName(srcSuffix);
        ImageReader reader = (ImageReader) iterator.next();

        InputStream in = new FileInputStream(src);
        ImageInputStream iis = ImageIO.createImageInputStream(in);
        reader.setInput(iis);

        BufferedImage srcBuffered = readBuffereImage(reader, w, h);
        BufferedImage targetBuffered = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);

        Graphics graphics = targetBuffered.getGraphics();
        graphics.drawImage(srcBuffered.getScaledInstance(w, h, Image.SCALE_DEFAULT), 0, 0, null); // 绘制缩小后的图

        graphics.dispose();
        srcBuffered.flush();
        in.close();
        iis.close();

        ImageIO.write(targetBuffered, srcSuffix, new File(dest));
        targetBuffered.flush();
    }

    private static BufferedImage readBuffereImage(ImageReader reader, int w, int h) throws IOException {
        ImageReadParam param = reader.getDefaultReadParam();
        int srcWidth = reader.getWidth(0);
        int srcHeight = reader.getHeight(0);

        Rectangle rect = null;

        if ((float) w / h > (float) srcWidth / srcHeight) {
            h = h * srcWidth / w;
            w = srcWidth;
            rect = new Rectangle(0, (srcHeight - h) / 2, w, h);
        } else {
            w = w * srcHeight / h;
            h = srcHeight;
            rect = new Rectangle((srcWidth - w) / 2, 0, w, h);
        }
        param.setSourceRegion(rect);
        BufferedImage srcBuffered = reader.read(0, param);
        return srcBuffered;
    }

    public final static void pressImage(String watermarkImg, String srcImageFile) {
        pressImage(watermarkImg, srcImageFile, srcImageFile, 5, -1, -1, 0.2f, 1);
    }

    public final static void pressImage(String watermarkImg, String srcImageFile, String destImageFile) {
        pressImage(watermarkImg, srcImageFile, destImageFile, 5, -1, -1, 0.2f, 1);
    }

    public final static void pressImage(String watermarkImg, String srcImageFile, String destImageFile, int position,
                                        float alpha) {
        pressImage(watermarkImg, srcImageFile, destImageFile, position, -1, -1, 0.2f, alpha);
    }

    /**
     * @param watermarkImg
     *            水印图片位置
     * @param srcImageFile
     *            源图片位置
     * @param destImageFile
     *            生成的图片位置
     * @param position
     *            水印打印的位置： 1->左上角，2->右上角，1->居中，1->左下角，1->右下角
     * @param xOffset
     *            x轴偏移量，xOffset小于0，自动偏移
     * @param yOffset
     *            y轴偏移量，yOffset小于0，自动偏移
     * @param radio
     *            默认为原图的 1/4
     * @param alpha
     *            透明度（0~1），PNG图片建议设置为1
     */
    public final static void pressImage(String watermarkImg, String srcImageFile, String destImageFile, int position,
                                        int xOffset, int yOffset, float radio, float alpha) {
        try {
            File img = new File(srcImageFile);
            Image src = ImageIO.read(img);
            int srcWidth = src.getWidth(null);
            int srcHeight = src.getHeight(null);

            BufferedImage image = new BufferedImage(srcWidth, srcHeight, BufferedImage.TYPE_INT_RGB);
            Graphics2D graphics = image.createGraphics();
            graphics.drawImage(src, 0, 0, srcWidth, srcHeight, null);

            // 水印文件
            Image wmImage = ImageIO.read(new File(watermarkImg));
            int wmWidth = wmImage.getWidth(null);
            int wmHeight = wmImage.getHeight(null);

            radio = radio <= 0 ? 0.2f : radio;
            int newWidth = (int) (srcWidth * radio);
            int newHeight = (int) (wmHeight * (newWidth / (float) wmWidth));

            xOffset = (xOffset < 0) ? (int) (newWidth * 0.1f) : xOffset;
            yOffset = (yOffset < 0) ? (int) (newHeight * 0.1f) : yOffset;

            int xPostion = 0;
            int yPostion = 0;

            switch (position) {
                case 1:
                    xPostion = xOffset;
                    yPostion = yOffset;
                    break;
                case 2:
                    xPostion = (int) (srcWidth * (1 - radio) - xOffset);
                    yPostion = yOffset;
                    break;
                case 3:
                    xPostion = (int) (srcWidth - newWidth) / 2;
                    yPostion = (int) (srcHeight - newHeight) / 2;
                    break;
                case 4:
                    xPostion = xOffset;
                    yPostion = (int) (srcHeight - newHeight - yOffset);
                    break;
                case 5:
                    xPostion = (int) (srcWidth * (1 - radio) - xOffset);
                    yPostion = (int) (srcHeight - newHeight - yOffset);
                    break;
                default:
                    xPostion = xOffset;
                    yPostion = yOffset;
                    break;
            }

            graphics.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));
            graphics.drawImage(wmImage, xPostion, yPostion, newWidth, newHeight, null);
            // 水印文件结束
            graphics.dispose();
            ImageIO.write((BufferedImage) image, "JPEG", new File(destImageFile));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}