package com.boman.file.utils;

import java.io.File;
import java.io.IOException;
import org.apache.commons.io.FilenameUtils;
import org.springframework.web.multipart.MultipartFile;
import com.boman.common.core.exception.file.FileNameLengthLimitExceededException;
import com.boman.common.core.exception.file.FileSizeLimitExceededException;
import com.boman.common.core.exception.file.InvalidExtensionException;
import com.boman.common.core.utils.DateUtils;
import com.boman.common.core.utils.StringUtils;
import com.boman.common.core.utils.file.MimeTypeUtils;
import sun.misc.BASE64Decoder;

/**
 * 文件上传工具类
 * 
 * @author ruoyi
 */
public class FileUploadUtils
{
    /**
     * 默认大小 50M
     */
    public static final long DEFAULT_MAX_SIZE = 50 * 1024 * 1024;

    /**
     * 默认的文件名最大长度 100
     */
    public static final int DEFAULT_FILE_NAME_LENGTH = 1000;

    /**
     * 根据文件路径上传
     *
     * @param baseDir 相对应用的基目录
     * @param file 上传的文件
     * @return 文件名称
     * @throws IOException
     */
    public static final String upload(String baseDir, MultipartFile file) throws IOException
    {
        try
        {
            return upload(baseDir, file, MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION);
        }
        catch (Exception e)
        {
            throw new IOException(e.getMessage(), e);
        }
    }

    /**
     * 文件上传
     *
     * @param baseDir 相对应用的基目录
     * @param file 上传的文件
     * @param allowedExtension 上传文件类型
     * @return 返回上传成功的文件名
     * @throws FileSizeLimitExceededException 如果超出最大大小
     * @throws FileNameLengthLimitExceededException 文件名太长
     * @throws IOException 比如读写文件出错时
     * @throws InvalidExtensionException 文件校验异常
     */
    public static final String upload(String baseDir, MultipartFile file, String[] allowedExtension)
            throws FileSizeLimitExceededException, IOException, FileNameLengthLimitExceededException,
            InvalidExtensionException
    {
        int fileNamelength = file.getOriginalFilename().length();
        if (fileNamelength > FileUploadUtils.DEFAULT_FILE_NAME_LENGTH)
        {
            throw new FileNameLengthLimitExceededException(FileUploadUtils.DEFAULT_FILE_NAME_LENGTH);
        }

        assertAllowed(file, allowedExtension);

        String fileName = extractFilename(file);

        File desc = getAbsoluteFile(baseDir, fileName);
        file.transferTo(desc);
        String pathFileName = getPathFileName(fileName);
        return pathFileName;
    }

    /**
     * 编码文件名
     */
    public static final String extractFilename(MultipartFile file)
    {
        String fileName = file.getOriginalFilename();
        String extension = getExtension(file);
        fileName = DateUtils.datePath() + "/" + System.currentTimeMillis() + "." + extension;
        return fileName;
    }

    private static final File getAbsoluteFile(String uploadDir, String fileName) throws IOException
    {
        File desc = new File(uploadDir + File.separator + fileName);

        if (!desc.exists())
        {
            if (!desc.getParentFile().exists())
            {
                desc.getParentFile().mkdirs();
            }
        }
        return desc.isAbsolute() ? desc : desc.getAbsoluteFile();
    }

    private static final String getPathFileName(String fileName) throws IOException
    {
        String pathFileName = "/" + fileName;
        return pathFileName;
    }

    /**
     * 文件大小校验
     *
     * @param file 上传的文件
     * @throws FileSizeLimitExceededException 如果超出最大大小
     * @throws InvalidExtensionException 文件校验异常
     */
    public static final void assertAllowed(MultipartFile file, String[] allowedExtension)
            throws FileSizeLimitExceededException, InvalidExtensionException
    {
        long size = file.getSize();
        if (DEFAULT_MAX_SIZE != -1 && size > DEFAULT_MAX_SIZE)
        {
            throw new FileSizeLimitExceededException(DEFAULT_MAX_SIZE / 1024 / 1024);
        }

        String fileName = file.getOriginalFilename();
        String extension = getExtension(file);
        if (allowedExtension != null && !isAllowedExtension(extension, allowedExtension))
        {
            if (allowedExtension == MimeTypeUtils.IMAGE_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidImageExtensionException(allowedExtension, extension,
                        fileName);
            }
            else if (allowedExtension == MimeTypeUtils.FLASH_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidFlashExtensionException(allowedExtension, extension,
                        fileName);
            }
            else if (allowedExtension == MimeTypeUtils.MEDIA_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidMediaExtensionException(allowedExtension, extension,
                        fileName);
            }
            else if (allowedExtension == MimeTypeUtils.VIDEO_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidVideoExtensionException(allowedExtension, extension,
                        fileName);
            }
            else
            {
                throw new InvalidExtensionException(allowedExtension, extension, fileName);
            }
        }
    }

    /**
     * 判断MIME类型是否是允许的MIME类型
     *
     * @param extension 上传文件类型
     * @param allowedExtension 允许上传文件类型
     * @return true/false
     */
    public static final boolean isAllowedExtension(String extension, String[] allowedExtension)
    {
        for (String str : allowedExtension)
        {
            if (str.equalsIgnoreCase(extension))
            {
                return true;
            }
        }
        return false;
    }

    /**
     * 获取文件名的后缀
     * 
     * @param file 表单文件
     * @return 后缀名
     */
    public static final String getExtension(MultipartFile file)
    {
        String extension = FilenameUtils.getExtension(file.getOriginalFilename());
        if (StringUtils.isEmpty(extension))
        {
            extension = MimeTypeUtils.getExtension(file.getContentType());
        }
        return extension;
    }

    /**
     * base64转MultipartFile
     * @param base64
     * @return
     */
    public static MultipartFile base64ToMultipart(String base64) {
        try {
            String[] baseStrs = base64.split(",");
            BASE64Decoder decoder = new BASE64Decoder();
            byte[] b;
            b = decoder.decodeBuffer(baseStrs[1]);
            for(int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {
                    b[i] += 256;
                }
            }
            return new Base64DecodedMultipartFile(b, baseStrs[0]);
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 功能描述: multipartFile转换成file
     *
     * @param multipartFile multipartFile
     * @return java.io.File
     */
    public static File multipartFile2File(MultipartFile multipartFile) {
        File file = new File("TEMP_FILE_PATH" + multipartFile.getOriginalFilename());
        transferTo(multipartFile, file);
        return file;
    }

    /**
     * 以流的形式存到服务器
     *
     * @param multipartFile multipartFile
     * @param newFile       newFile
     */
    private static void transferTo(MultipartFile multipartFile, File newFile) {
        try {
            if (!newFile.getParentFile().exists()) {
                newFile.getParentFile().mkdirs();
            }
            multipartFile.transferTo(newFile);
        } catch (Exception ignored) {
        }
    }

    /**
     * 功能描述: 删除临时文件
     *
     * @param file file
     */
    public static void delete(File file) {
        if (file != null) {
            file.delete();
        }
    }

}