package com.cn.fdapfe.common.utils.file;

import java.io.File;
import java.io.IOException;
import java.text.DecimalFormat;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import org.apache.commons.io.FilenameUtils;
import org.springframework.web.multipart.MultipartFile;
import com.cn.fdapfe.common.config.RuoYiConfig;
import com.cn.fdapfe.common.constant.Constants;
import com.cn.fdapfe.common.exception.file.FileNameLengthLimitExceededException;
import com.cn.fdapfe.common.exception.file.FileSizeLimitExceededException;
import com.cn.fdapfe.common.exception.file.InvalidExtensionException;
import com.cn.fdapfe.common.utils.DateUtils;
import com.cn.fdapfe.common.utils.StringUtils;
import com.cn.fdapfe.common.utils.uuid.Seq;

/**
 * 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 * 1024L;

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

    /**
     * 默认上传的地址
     */
    private static String defaultBaseDir = RuoYiConfig.getProfile();

    public static void setDefaultBaseDir(String defaultBaseDir)
    {
        FileUploadUtils.defaultBaseDir = defaultBaseDir;
    }

    public static String getDefaultBaseDir()
    {
        return defaultBaseDir;
    }

    /**
     * 以默认配置进行文件上传
     *
     * @param file 上传的文件
     * @return 文件名称
     * @throws Exception
     */
    public static final Map upload(MultipartFile file) throws IOException
    {
        try
        {
            return upload(getDefaultBaseDir(), file, MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION);
        }
        catch (Exception e)
        {
            throw new IOException(e.getMessage(), e);
        }
    }

    /**
     * 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 Map 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
     */
    private static final DecimalFormat FILE_SIZE_FORMAT = new DecimalFormat("0.00");

    public static final Map upload(String baseDir, MultipartFile file, String[] allowedExtension)
            throws FileSizeLimitExceededException, IOException, FileNameLengthLimitExceededException,
            InvalidExtensionException {
        int fileNamelength = Objects.requireNonNull(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);
        long fileSizeBytes = file.getSize(); // 原始字节大小

        // 转换为可读的文件大小（KB/MB）
        String fileSize = formatFileSize(fileSizeBytes);

        String absPath = getAbsoluteFile(baseDir, fileName).getAbsolutePath();
        file.transferTo(Paths.get(absPath));

        Map<String, Object> resultMap = getPathFileName(baseDir, fileName);
        resultMap.put("fileSize", fileSize);         // 转换后的可读大小（KB/MB）
        resultMap.put("fileSizeBytes", String.valueOf(fileSizeBytes)); // 保留原始字节大小（可选）
        resultMap.put("fileSuffix", getExtension(file));   //文件后缀
        return resultMap;
    }

    /**
     * 将字节大小转换为 KB/MB 格式（保留两位小数）
     * @param size 字节大小
     * @return 格式化后的字符串（如 "1.23MB" 或 "456.78KB"）
     */
    private static String formatFileSize(long size) {
        if (size < 1024) {
            return size + "B";
        } else if (size < 1024 * 1024) {
            double kb = size / 1024.0;
            return FILE_SIZE_FORMAT.format(kb) + "KB";
        } else {
            double mb = size / (1024.0 * 1024);
            return FILE_SIZE_FORMAT.format(mb) + "MB";
        }
    }


    /**
     * 编码文件名
     */
    public static final String extractFilename(MultipartFile file)
    {
        return StringUtils.format("{}/{}_{}.{}", DateUtils.datePath(),
                FilenameUtils.getBaseName(file.getOriginalFilename()), Seq.getId(Seq.uploadSeqType), getExtension(file));
    }

    public 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;
    }

    public static final Map getPathFileName(String uploadDir, String fileName) throws IOException {
        // 查找最后一个斜杠的位置（处理可能的多级目录）
        String FileLicationPath = uploadDir + "/" + fileName;
        int lastSlashIndex = FileLicationPath.lastIndexOf('/');
        String datePath = FileLicationPath.substring(0, lastSlashIndex);
        if (lastSlashIndex != -1) {
            fileName = FileLicationPath.substring(lastSlashIndex + 1);
        }
        HashMap<String, String> fileInfoMap = new HashMap<>();
        fileInfoMap.put("fileName", fileName);          // 文件名称（不带路径）
        fileInfoMap.put("filelocalPath", datePath);      // 本地存储路径（带目录）
        fileInfoMap.put("infoPath",FileLicationPath);
        return fileInfoMap;
    }

    /**
     * 文件大小校验
     *
     * @param file 上传的文件
     * @return
     * @throws FileSizeLimitExceededException 如果超出最大大小
     * @throws InvalidExtensionException
     */
    public static final void assertAllowed(MultipartFile file, String[] allowedExtension)
            throws FileSizeLimitExceededException, InvalidExtensionException
    {
        long size = file.getSize();
        if (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
     * @param allowedExtension
     * @return
     */
    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(Objects.requireNonNull(file.getContentType()));
        }
        return extension;
    }
}
