import com.jcraft.jsch.*;

import com.jcraft.jsch.ChannelSftp.LsEntry;

import lombok.extern.slf4j.Slf4j;

import org.springframework.stereotype.Component;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.util.Properties;

import java.util.Vector;

@Component

@Slf4j

public class SFTPUtils {

    private SFTPUtils instance = null;

    private ChannelSftp sftp;

    public File downloadFtpFile(String ftpHost,String ftpUserName,String ftpPassword,int ftpPort,String ftpPath,String localPath, String fileName, String downName){

        if(null==instance){

            instance=new SFTPUtils();

        }

        //获取SFTP连接

        sftp = instance.connect(ftpHost, ftpPort, ftpUserName,ftpPassword);

        //SFTP上下载文件

        return instance.download(ftpPath+fileName, localPath+downName);

    }

    /**

     * 连接sftp服务器

     *

     * @param host     主机

     * @param port     端口

     * @param username 用户名

     * @param password 密码

     * @return

     */

    public  ChannelSftp connect(String host, int port, String username, String password) {

        ChannelSftp sftp = null;

        try {

            JSch jsch = new JSch();

            jsch.getSession(username, host, port);

            Session sshSession = jsch.getSession(username, host, port);

            sshSession.setPassword(password);

            Properties sshConfig = new Properties();

            sshConfig.put("StrictHostKeyChecking", "no");

            sshSession.setConfig(sshConfig);

            sshSession.connect();

            log.info("SFTP Session connected.");

            Channel channel = sshSession.openChannel("sftp");

            channel.connect();

            sftp = (ChannelSftp) channel;

            log.info("Connected to " + host);

        } catch (Exception e) {

            log.error(e.getMessage());

        }

        return sftp;

    }

    /**

     * 上传文件

     *

     * @param directory  上传的目录

     * @param uploadFile 要上传的文件

     */

    public boolean upload(String directory, String uploadFile) {

        try {

            sftp.cd(directory);

            File file = new File(uploadFile);

            FileInputStream fileInputStream = new FileInputStream(file);

            sftp.put(fileInputStream, file.getName());

            fileInputStream.close();

            return true;

        } catch (Exception e) {

            log.error(e.getMessage());

            return false;

        }

    }

    /**

     * 下载文件

     *

     * @param directory    下载目录

     * @param downloadFile 下载的文件

     * @param saveFile     存在本地的路径

     */

    public File download(String directory, String downloadFile, String saveFile) {

        try {

            sftp.cd(directory);

            File file = new File(saveFile);

            FileOutputStream fileOutputStream = new FileOutputStream(file);

            sftp.get(downloadFile, fileOutputStream);

            fileOutputStream.close();

            return file;

        } catch (Exception e) {

            log.error(e.getMessage());

            return null;

        }

    }

    /**

     * 下载文件

     *

     * @param downloadFilePath 下载的文件完整目录

     * @param saveFile         存在本地的路径

     */

    public File download(String downloadFilePath, String saveFile) {

        try {

            int i = downloadFilePath.lastIndexOf('/');

            if (i == -1)

                return null;

            sftp.cd(downloadFilePath.substring(0, i));

            File file = new File(saveFile);

            FileOutputStream fileOutputStream = new FileOutputStream(file);

            sftp.get(downloadFilePath.substring(i + 1), fileOutputStream);

            fileOutputStream.close();

            return file;

        } catch (Exception e) {

            log.error(e.getMessage());

            return null;

        }

    }

    /**

     * 删除文件

     *

     * @param directory  要删除文件所在目录

     * @param deleteFile 要删除的文件

     */

    public void delete(String directory, String deleteFile) {

        try {

            sftp.cd(directory);

            sftp.rm(deleteFile);

        } catch (Exception e) {

            log.error(e.getMessage());

        }

    }

    /**

     * 断开连接

     */

    public void disconnect() {

        try {

            sftp.getSession().disconnect();

        } catch (JSchException e) {

            log.error(e.getMessage());

        }

        sftp.quit();

        sftp.disconnect();

    }

    /**

     * 列出目录下的文件

     *

     * @param directory 要列出的目录

     * @throws SftpException

     */

    @SuppressWarnings("unused")

    public Vector<LsEntry> listFiles(String directory) throws SftpException {

        return sftp.ls(directory);

    }

}