package com.newfiber.termite.util;

import com.newfiber.common.core.exception.file.FileNameLengthLimitExceededException;
import com.newfiber.common.core.exception.file.FileSizeLimitExceededException;
import com.newfiber.common.core.exception.file.InvalidExtensionException;
import com.newfiber.common.core.utils.DateUtils;
import com.newfiber.common.core.utils.StringUtils;
import com.newfiber.common.core.utils.file.FileTypeUtils;
import com.newfiber.common.core.utils.file.MimeTypeUtils;
import com.newfiber.common.core.utils.uuid.Seq;
import org.apache.commons.io.FilenameUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.Objects;

/**
 * 文件上传工具类
 * 
 * @author newfiber
 */
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 = 100;

    /**
     * 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 = 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);

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

    /**
     * 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), FileTypeUtils
		        .getExtension(file));
    }

    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 (size > DEFAULT_MAX_SIZE){
            throw new FileSizeLimitExceededException(DEFAULT_MAX_SIZE / 1024 / 1024);
        }

        String fileName = file.getOriginalFilename();
        String extension = FileTypeUtils.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;
    }
}