package com.lf.server.helper;

import java.io.File;
import java.util.Date;

/**
 * 文件帮助类
 * @author WWW
 */
public class FileHelper {
    private final static String POINT = ".";

    /**
     * 获取文件扩展名
     */
    public static String getExtension(File file) {
        if (file == null) {
            return null;
        }

        String fileName = file.getName().toLowerCase();

        int idx = fileName.lastIndexOf(POINT);
        if (idx == -1) {
            return "";
        }

        return fileName.substring(idx);
    }

    /**
     * 获取文件扩展名
     */
    public static String getExtension(String fileName) {
        if (StringHelper.isEmpty(fileName)) {
            return "";
        }

        int idx = fileName.lastIndexOf(POINT);
        if (idx == -1) {
            return "";
        }

        return fileName.substring(idx).toLowerCase();
    }

    /**
     * 获取多用途互联网邮件扩展类型
     *
     * @param ext 文件扩展名
     * @return
     */
    public static String getMime(String ext) {
        switch (ext) {
            // 图片
            case ".tif":
            case ".tiff":
                return "image/tiff";
            case ".img":
                return "application/x-img";
            case ".gif":
                return "image/gif";
            case ".jpg":
            case ".jpeg":
                return "image/jpeg";
            case ".png":
                return "image/png";
            // 音/视频
            case ".mp3":
                return "audio/mp3";
            case ".mp4":
                return "video/mpeg4";
            case ".avi":
                return "video/avi";
            case ".mpg":
            case ".mpeg":
                return "video/mpg";
            case ".wav":
                return "audio/wav";
            case ".wma":
                return "audio/x-ms-wma";
            case ".swf":
                return "application/x-shockwave-flash";
            case ".wmv":
                return "video/x-ms-wmv";
            case ".rm":
                return "application/vnd.rn-realmedia";
            case ".rmvb":
                return "application/vnd.rn-realmedia-vbr";
            // 网页
            case ".js":
                return "application/x-javascript";
            case ".css":
                return "text/css";
            case ".asp":
                return "text/asp";
            case ".mht":
                return "message/rfc822";
            case ".jsp":
            case ".htm":
            case ".html":
            case ".xhtml":
                return "text/html";
            case ".xml":
            case ".svg":
                return "text/xml";
            // 文件
            case ".txt":
                return "text/plain";
            case ".dbf":
                return "application/x-dbf";
            case ".mdb":
                return "application/msaccess";
            case ".pdf":
                return "application/pdf";
            case ".ppt":
            case ".pptx":
                return "application/x-ppt";
            case ".doc":
            case ".docx":
                return "application/msword";
            case ".xls":
            case ".xlsx":
                return "application/vnd.ms-excel";
            case ".dgn":
                return "application/x-dgn";
            case ".dwg":
                return "application/x-dwg";
            case ".ext":
                return "application/x-msdownload";
            // 默认
            default:
                return "application/octet-stream";
        }
    }

    /**
     * 获取临时路径
     *
     * @return
     */
    public static String getTempPath() {
        return StringHelper.YMD_HM_FORMAT.format(new Date());
    }
}