package com.ynxbd.common.helper.common;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.UUID;

/**
 * @Author wsq
 * @Date 2020/8/3 15:37
 * @Copyright @ 2020 云南新八达科技有限公司 All rights reserved.
 */
public class Base64Helper {

    /**
     * BASE64解密
     *
     * @param data data
     * @return 解密后的内容
     */
    public static String decode(String data) {
        return new String(java.util.Base64.getDecoder().decode(data), StandardCharsets.UTF_8); //
    }

    /**
     * BASE64解密
     *
     * @param data 解密
     * @return 解密后的内容
     */
    public static byte[] decodeByte(String data) {
        try {
            return java.util.Base64.getDecoder().decode(data);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * BASE64加密
     *
     * @param data 需要加密的字符串
     * @return 加密后的字符串
     */
    public static String encode(String data) {
        return java.util.Base64.getEncoder().encodeToString(data.getBytes(StandardCharsets.UTF_8));
    }

    /**
     * BASE64加密
     *
     * @param obj 需要加密的字符串
     * @return 加密后的字符串
     */
    public static String encode(Object obj, Boolean isEncryption) {
        if (obj == null) return null;
        String encode;
        if (obj.getClass() != String.class) {
            encode = JsonHelper.toJsonString(obj);
        } else {
            encode = obj.toString();
        }

        if ("".equals(encode)) {
            return null;
        }

        encode = java.util.Base64.getEncoder().encodeToString(encode.getBytes(StandardCharsets.UTF_8));
        if (isEncryption) {
            String uuid = UUID.randomUUID().toString().replace("-", "");

            if (encode.length() > 25) {
                String begStr = encode.substring(0, 10);
                String endStr = encode.substring(encode.length() - 15, encode.length() - 5);
                String end = encode.substring(encode.length() - 5);
                String middle = encode.substring(10, encode.length() - 15);
                return uuid + endStr + middle + begStr + end;
            } else {
                encode = uuid + encode;
            }
        }
        return encode;
    }


    // 判断是否只有数字和字母
    public static boolean isLetterDigit(String str) {
        return str.matches("^[a-z0-9A-Z]+$");
    }

    /**
     * 解密
     *
     * @param data 需要解密的字符串
     */
    public static String decodeEn(String data) {
        try {
            if (data == null) {
                return null;
            }
            int dataLen = data.length();
            if (dataLen > 32) { // 截取掉uuid
                data = data.substring(32);
            }
            if (dataLen > 57) { // 超过57位的需要调换前后位置
                String endStr = data.substring(0, 10);
                String begStr = data.substring(data.length() - 15, data.length() - 5);
                String middle = data.substring(10, data.length() - 15);
                String end = data.substring(data.length() - 5);
                data = begStr + middle + endStr + end;
            }
            String deData = new String(Base64.getDecoder().decode(data), StandardCharsets.UTF_8);// base64解密
            if (!isLetterDigit(deData)) {
                return null;
            }
            return deData;
        } catch (Exception e) {
            return null;
        }
    }


    /**
     * 将图片转换成Base64编码
     *
     * @param imgFile 图片文件
     * @return base64
     */
    public static String imageToBase(File imgFile) {
        try (FileInputStream fis = new FileInputStream(imgFile)) {
            byte[] buffer = new byte[(int) imgFile.length()];
            fis.read(buffer);
            return java.util.Base64.getEncoder().encodeToString(buffer);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String pdfBaseToImgBase(String base64) {
        return pdfBaseToImgBase(base64, null);
    }


    public static String pdfBaseToImgBase(String base64, Integer dpi) {
        if (base64 == null) {
            return null;
        }
        String imgBase64;
        PDDocument pdDoc = null;
        ByteArrayOutputStream bos = null;
        if (dpi == null) {
            dpi = 100;
        }
        try {
            // Base64解码
            byte[] pdfBytes = java.util.Base64.getDecoder().decode(base64);
            pdDoc = PDDocument.load(pdfBytes);
            int size = pdDoc.getNumberOfPages();
            /*图像合并使用的参数*/

            int width = 0;
            int height = 0;
            // 保存一张图片中的RGB数据
            int[] singleImgRGB;
            //保存每张图片的像素值
            BufferedImage imageResult = null;
            // 利用PdfBox生成图像
            PDFRenderer renderer = new PDFRenderer(pdDoc);
            /* 根据总页数, 按照50页生成一张长图片的逻辑, 进行拆分--每50页转成1张图片--总计循环的次数 */

            BufferedImage image;
            int imageHeight, imageWidth, pageIndex;
            int totalCount = pdDoc.getNumberOfPages() / size + 1;
            for (int m = 0; m < totalCount; m++) {
                for (int i = 0; i < size; i++) {
                    pageIndex = i + (m * size);
                    if (pageIndex == pdDoc.getNumberOfPages()) {
                        break;
                    }
                    // 96为图片的dpi，dpi越大，则图片越清晰，图片越大，转换耗费的时间也越多
                    image = renderer.renderImageWithDPI(pageIndex, dpi, ImageType.RGB);
                    imageHeight = image.getHeight();
                    imageWidth = image.getWidth();
                    if (i == 0) {
                        // 计算高度和偏移量 使用第一张图片宽度;
                        width = imageWidth;
                        // 保存每页图片的像素值
                        // 加个判断：如果m次循环后所剩的图片总数小于pageLength，则图片高度按剩余的张数绘制，否则会出现长图片下面全是黑色的情况
                        if ((pdDoc.getNumberOfPages() - m * size) < size) {
                            imageResult = new BufferedImage(width, imageHeight * (pdDoc.getNumberOfPages() - m * size), BufferedImage.TYPE_INT_RGB);
                        } else {
                            imageResult = new BufferedImage(width, imageHeight * size, BufferedImage.TYPE_INT_RGB);
                        }
                    } else {
                        // 将高度不断累加
                        height += imageHeight;
                    }
                    singleImgRGB = image.getRGB(0, 0, width, imageHeight, null, 0, width);
                    imageResult.setRGB(0, height, width, imageHeight, singleImgRGB, 0, width);
                }
                // 这个很重要，下面会有说明
                height = 0;
            }

            if (imageResult == null) {
                return null;
            }

            bos = new ByteArrayOutputStream();//io流
            ImageIO.write(imageResult, "png", bos);//写入流中

            imgBase64 = java.util.Base64.getEncoder().encodeToString(bos.toByteArray()).trim();
            imgBase64 = "data:image/png;base64," + imgBase64.replaceAll("\n", "").replaceAll("\r", ""); //删除 \r\n
            return imgBase64;
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bos != null) {
                    bos.flush();
                    bos.close();
                }

                if (pdDoc != null) {
                    pdDoc.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }

//    public static void main(String[] args) {
//        String a = encode("123456789011121314151123123", true);
//        System.out.println(a);
//        String s = decodeEn(a);
//        System.out.println(s);
//    }

//    public static void main(String[] args) {
//        String encode = CodeHelper.get28UUID() + encode(JsonHelper.toJsonString(new ArrayList<>()));
//        System.out.println(encode);
//    }

    public static void main(String[] args) {
    }
}