package com.fdkk.fdkkmeta.util;

import cn.hutool.core.io.IoUtil;
import com.alibaba.fastjson.util.IOUtils;
import org.springframework.util.MimeTypeUtils;
import org.yaml.snakeyaml.util.ArrayUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

/**
 * 文件处理工具类
 *
 * @author fdkk
 */
public class FileUtils {
    private static String FILENAME_PATTERN = "[a-zA-Z0-9_\\-\\|\\.\\u4e00-\\u9fa5]+";

    /**
     * 输出指定文件的byte数组
     *
     * @param filePath 文件路径
     * @param os       输出流
     * @return
     */
    public static void writeBytes(String filePath, OutputStream os) throws IOException {
        FileInputStream fis = null;
        try {
            File file = new File(filePath);
            if (!file.exists()) {
                throw new FileNotFoundException(filePath);
            }
            fis = new FileInputStream(file);
            byte[] b = new byte[1024];
            int length;
            while ((length = fis.read(b)) > 0) {
                os.write(b, 0, length);
            }
        } catch (IOException e) {
            throw e;
        } finally {
            IOUtils.close(os);
            IOUtils.close(fis);
        }
    }


    /**
     * 删除文件
     *
     * @param filePath 文件
     * @return
     */
    public static boolean deleteFile(String filePath) {
        boolean flag = false;
        File file = new File(filePath);
        // 路径为文件且不为空则进行删除
        if (file.isFile() && file.exists()) {
            file.delete();
            flag = true;
        }
        return flag;
    }

    /**
     * 文件名称验证
     *
     * @param filename 文件名称
     * @return true 正常 false 非法
     */
    public static boolean isValidFilename(String filename) {
        return filename.matches(FileUtils.FILENAME_PATTERN);
    }


    public static List<String> readFileByLines2(String path) {
        File f = new File(path);
        if (!f.exists()) {
            return null;
        }

        FileReader reader = null;
        BufferedReader br = null;
        try {
            // read file content from file
            reader = new FileReader(path);
            br = new BufferedReader(reader);

            String str = null;
            List<String> result = new ArrayList<String>();
            while ((str = br.readLine()) != null) {
                result.add(str);
            }


            return result;
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            IoUtil.close(reader);
            IoUtil.close(br);
        }
        return null;
    }



    /**
     * 下载文件名重新编码
     *
     * @param response     响应对象
     * @param realFileName 真实文件名
     * @return
     */
    public static void setAttachmentResponseHeader(HttpServletResponse response, String realFileName) throws UnsupportedEncodingException {
        String percentEncodedFileName = FileUtils.percentEncode(realFileName);

        StringBuilder contentDispositionValue = new StringBuilder();
        contentDispositionValue.append("attachment; filename=")
                .append(percentEncodedFileName)
                .append(";")
                .append("filename*=")
                .append("utf-8''")
                .append(percentEncodedFileName);

        response.setHeader("Content-disposition", contentDispositionValue.toString());
        response.setHeader("download-filename", percentEncodedFileName);
    }

    /**
     * 百分号编码工具方法
     *
     * @param s 需要百分号编码的字符串
     * @return 百分号编码后的字符串
     */
    private static String percentEncode(String s) throws UnsupportedEncodingException {
        String encode = URLEncoder.encode(s, StandardCharsets.UTF_8.toString());
        return encode.replaceAll("\\+", "%20");
    }

    /**
     * 获取图像后缀
     *
     * @param photoByte 图像数据
     * @return 后缀名
     */
    private static String getFileExtendName(byte[] photoByte) {
        String strFileExtendName = "jpg";
        if ((photoByte[0] == 71) && (photoByte[1] == 73) && (photoByte[2] == 70) && (photoByte[3] == 56)
                && ((photoByte[4] == 55) || (photoByte[4] == 57)) && (photoByte[5] == 97)) {
            strFileExtendName = "gif";
        } else if ((photoByte[6] == 74) && (photoByte[7] == 70) && (photoByte[8] == 73) && (photoByte[9] == 70)) {
            strFileExtendName = "jpg";
        } else if ((photoByte[0] == 66) && (photoByte[1] == 77)) {
            strFileExtendName = "bmp";
        } else if ((photoByte[1] == 80) && (photoByte[2] == 78) && (photoByte[3] == 71)) {
            strFileExtendName = "png";
        }
        return strFileExtendName;
    }
}