package ssh

import (
	"bytes"
	"errors"
	"io"
	"io/ioutil"
	"log"
	"os"
	"path"
	"path/filepath"
	"strings"
)

// Upload 上传本地文件 local 到sftp远程目录 remote like rsync
// rsync -av src/ dst     ./src/* --> /root/dst/*
// rsync -av src/ dst/    ./src/* --> /root/dst/*
// rsync -av src  dst     ./src/* --> /root/dst/src/*
// rsync -av src  dst/    ./src/* --> /root/dst/src/*
func (c *Client) Upload(local string, remote string) (err error) {
	// var localDir, localFile, remoteDir, remoteFile string

	info, err := os.Stat(local)
	if err != nil {
		return errors.New("sftp: 跳过上传 Upload(\"" + local + "\") ,本地文件不存在或格式错误!")
	}
	if info.IsDir() {
		log.Println("sftp: UploadDir", local)
		return c.UploadDir(local, remote)
	}
	return c.UploadFile(local, remote)
}

// Download 下载sftp远程文件 remote 到本地 local like rsync
func (c *Client) Download(remote string, local string) (err error) {
	if c.IsNotExist(strings.TrimSuffix(remote, "/")) {
		return errors.New("sftp: 远程文件不存在,跳过文件下载 \"" + remote + "\" ")
	}
	if c.IsDir(remote) {
		// return errors.New("检测到远程是文件不是目录 \"" + remote + "\" 跳过下载")
		return c.downloadDir(remote, local)

	}
	return c.downloadFile(remote, local)

}

// downloadFile a file from the remote server like cp
func (c *Client) downloadFile(remoteFile, local string) error {
	// remoteFile = strings.TrimSuffix(remoteFile, "/")
	if !c.IsFile(remoteFile) {
		return errors.New("sftp: 文件不存在或不是文件, 跳过目录下载 downloadFile(" + remoteFile + ")")
	}
	var localFile string
	if local[len(local)-1] == '/' {
		localFile = filepath.Join(local, filepath.Base(remoteFile))
	} else {
		localFile = local
	}
	localFile = filepath.ToSlash(localFile)
	if c.Size(remoteFile) > 1000 {
		rsum := c.Md5File(remoteFile)
		ioutil.WriteFile(localFile+".md5", []byte(rsum), 0755)
		if FileExist(localFile) {
			if rsum != "" {
				lsum, _ := Md5File(localFile)
				if lsum == rsum {
					log.Println("sftp: 文件与本地一致，跳过下载！", localFile)
					return nil
				}
				log.Println("sftp: 正在下载 ", localFile)
			}
		}
	}
	if err := os.MkdirAll(filepath.Dir(localFile), os.ModePerm); err != nil {
		// log.Println(err)
		return err
	}

	r, err := c.SFTPClient.Open(remoteFile)
	if err != nil {
		return err
	}
	defer r.Close()

	l, err := os.Create(localFile)
	if err != nil {
		return err
	}
	defer l.Close()

	_, err = io.Copy(l, r)
	return err
}

// downloadDir from remote dir to local dir like rsync
// rsync -av src/ dst     ./src/* --> /root/dst/*
// rsync -av src/ dst/    ./src/* --> /root/dst/*
// rsync -av src  dst     ./src/* --> /root/dst/src/*
// rsync -av src  dst/    ./src/* --> /root/dst/src/*
func (c *Client) downloadDir(remote, local string) error {
	var localDir, remoteDir string

	if !c.IsDir(remote) {
		return errors.New("sftp: 目录不存在或不是目录, 跳过 downloadDir(" + remote + ")")
	}
	remoteDir = remote
	if remote[len(remote)-1] == '/' {
		localDir = local
	} else {
		localDir = path.Join(local, path.Base(remote))
	}

	walker := c.SFTPClient.Walk(remoteDir)

	for walker.Step() {
		if err := walker.Err(); err != nil {
			log.Println(err)
			continue
		}

		info := walker.Stat()

		relPath, err := filepath.Rel(remoteDir, walker.Path())
		if err != nil {
			return err
		}

		localPath := filepath.ToSlash(filepath.Join(localDir, relPath))

		// if we have something at the download path delete it if it is a directory
		// and the remote is a file and vice a versa
		localInfo, err := os.Stat(localPath)
		if os.IsExist(err) {
			if localInfo.IsDir() {
				if info.IsDir() {
					continue
				}

				err = os.RemoveAll(localPath)
				if err != nil {
					return err
				}
			} else if info.IsDir() {
				err = os.Remove(localPath)
				if err != nil {
					return err
				}
			}
		}

		if info.IsDir() {
			err = os.MkdirAll(localPath, os.ModePerm)
			if err != nil {
				return err
			}

			continue
		}

		c.downloadFile(walker.Path(), localPath)

	}
	return nil
}

//UploadFile 上传本地文件 localFile 到sftp远程目录 remote
func (c *Client) UploadFile(localFile, remote string) error {
	// localFile = strings.TrimSuffix(localFile, "/")
	// localFile = filepath.ToSlash(localFile)
	info, err := os.Stat(localFile)
	if err != nil || info.IsDir() {
		return errors.New("sftp: 本地文件不存在,或是不是文件 UploadFile(\"" + localFile + "\") 跳过上传")
	}

	l, err := os.Open(localFile)
	if err != nil {
		return err
	}
	defer l.Close()

	var remoteFile, remoteDir string
	if remote[len(remote)-1] == '/' {
		remoteFile = filepath.ToSlash(filepath.Join(remote, filepath.Base(localFile)))
		remoteDir = remote
	} else {
		remoteFile = remote
		remoteDir = filepath.ToSlash(filepath.Dir(remoteFile))
	}
	log.Println("sftp: UploadFile", localFile, remoteFile)
	if info.Size() > 1000 {
		// 1. 检测远程是否存在
		rsum := c.Md5File(remoteFile)
		if rsum != "" {
			lsum, _ := Md5File(localFile)
			if lsum == rsum {
				log.Println("sftp: 文件与本地一致，跳过上传！", localFile)
				return nil
			}
			log.Println("sftp: 正在上传 ", localFile)
		}
	}

	// 目录不存在,则创建 remoteDir
	if _, err := c.SFTPClient.Stat(remoteDir); err != nil {
		log.Println("sftp: Mkdir all", remoteDir)
		c.MkdirAll(remoteDir)
	}

	r, err := c.SFTPClient.Create(remoteFile)
	if err != nil {
		return err
	}

	_, err = io.Copy(r, l)
	return err
}

// UploadDir files without checking diff status
func (c *Client) UploadDir(localDir string, remoteDir string) (err error) {
	// defer func() {
	// 	if err != nil {
	// 		err = errors.New("UploadDir " + err.Error())
	// 	}
	// }()
	// 本地输入检测,必须是目录
	// localDir = filepath.ToSlash(localDir)
	info, err := os.Stat(localDir)
	if err != nil || !info.IsDir() {
		return errors.New("sftp: 本地目录不存在或不是目录 UploadDir(\"" + localDir + "\") 跳过上传")
	}

	// 模仿 rsync localDir不以'/'结尾,则创建尾目录
	if localDir[len(localDir)-1] != '/' {
		remoteDir = filepath.ToSlash(filepath.Join(remoteDir, filepath.Base(localDir)))
	}
	log.Println("sftp: UploadDir", localDir, remoteDir)

	rootDst := strings.TrimSuffix(remoteDir, "/")
	if c.IsFile(rootDst) {
		c.SFTPClient.Remove(rootDst)
	}

	walkFunc := func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		// Calculate the final destination using the
		// base source and root destination
		relSrc, err := filepath.Rel(localDir, path)
		if err != nil {
			return err
		}
		finalDst := filepath.Join(rootDst, relSrc)

		// In Windows, Join uses backslashes which we don't want to get
		// to the sftp server
		finalDst = filepath.ToSlash(finalDst)

		// Skip the creation of the target destination directory since
		// it should exist and we might not even own it
		if finalDst == remoteDir {
			return nil

		}

		if info.IsDir() {
			err := c.MkdirAll(finalDst)
			if err != nil {
				log.Println("sftp: MkdirAll", err)
			}
			// log.Println("MkdirAll", finalDst)
			// err = c.SFTPClient.Mkdir(finalDst)
			// log.Println(err)
			// if err := c.SFTPClient.Mkdir(finalDst); err != nil {
			// 	// Do not consider it an error if the directory existed
			// 	remoteFi, fiErr := c.SFTPClient.Lstat(finalDst)
			// 	if fiErr != nil || !remoteFi.IsDir() {
			// 		return err
			// 	}
			// }
			// return err
		} else {
			// f, err := os.Open(path)
			// if err != nil {
			// 	return err
			// }
			// defer f.Close()
			return c.UploadFile(path, finalDst)
		}
		return nil

	}
	return filepath.Walk(localDir, walkFunc)
}

// Remove a file from the remote server
func (c *Client) Remove(path string) error {
	return c.SFTPClient.Remove(path)
}

// RemoveDirectory Remove a directory from the remote server
func (c *Client) RemoveDirectory(path string) error {
	return c.SFTPClient.RemoveDirectory(path)
}

// ReadAll Read a remote file and return the contents.
func (c *Client) ReadAll(filepath string) ([]byte, error) {
	file, err := c.SFTPClient.Open(filepath)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	return ioutil.ReadAll(file)
}

//FileExist 文件是否存在
func (c *Client) FileExist(filepath string) (bool, error) {
	if _, err := c.SFTPClient.Stat(filepath); err != nil {
		return false, err
	}
	return true, nil
}

func (c *Client) RemoveFile(remoteFile string) error {
	return c.SFTPClient.Remove(remoteFile)
}
func (c *Client) RemoveDir(remoteDir string) error {
	remoteFiles, err := c.SFTPClient.ReadDir(remoteDir)
	if err != nil {
		log.Printf("sftp: remove remote dir: %s err: %v\n", remoteDir, err)
		return err
	}
	for _, file := range remoteFiles {
		subRemovePath := path.Join(remoteDir, file.Name())
		if file.IsDir() {
			c.RemoveDir(subRemovePath)
		} else {
			c.RemoveFile(subRemovePath)
		}
	}
	c.SFTPClient.RemoveDirectory(remoteDir) //must empty dir to remove
	log.Printf("sftp: remove remote dir: %s ok\n", remoteDir)
	return nil
}

//RemoveAll 递归删除目录，文件
func (c *Client) RemoveAll(remoteDir string) error {
	c.RemoveDir(remoteDir)
	return nil
}

//MkdirAll 创建目录，递归
func (c *Client) MkdirAll(dirpath string) error {
	_, err := c.SFTPClient.Stat(dirpath)
	if err != nil {
		if err.Error() == "file does not exist" {
			e := c.MkdirAll(filepath.ToSlash(filepath.Dir(dirpath)))
			if e != nil {
				return e
			}
		} else {
			return err
		}
	}
	if err != nil && err.Error() == "file does not exist" {
		err = c.SFTPClient.Mkdir(dirpath)
		if err != nil {
			return err
		}
	}
	return err
}

func (c *Client) Mkdir(path string, fi os.FileInfo) error {
	log.Printf("[DEBUG] sftp: creating dir %s", path)

	if err := c.SFTPClient.Mkdir(path); err != nil {
		// Do not consider it an error if the directory existed
		remoteFi, fiErr := c.SFTPClient.Lstat(path)
		if fiErr != nil || !remoteFi.IsDir() {
			return err
		}
	}

	mode := fi.Mode().Perm()
	if err := c.SFTPClient.Chmod(path, mode); err != nil {
		return err
	}
	return nil
}

//IsDir 检查远程是否是个目录
func (c *Client) IsDir(path string) bool {
	// 检查远程是文件还是目录
	info, err := c.SFTPClient.Stat(path)
	if err == nil && info.IsDir() {
		return true
	}
	return false
}

//Size 获取文件大小
func (c *Client) Size(path string) int64 {
	info, err := c.SFTPClient.Stat(path)
	if err != nil {
		return 0
	}
	return info.Size()
}

//IsFile 检查远程是否是个文件
func (c *Client) IsFile(path string) bool {
	info, err := c.SFTPClient.Stat(path)
	if err == nil && !info.IsDir() {
		return true
	}
	return false
}

//IsNotExist 检查远程是文件是否不存在
func (c *Client) IsNotExist(path string) bool {
	_, err := c.SFTPClient.Stat(path)
	return err != nil
}

//IsExist 检查远程是文件是否存在
func (c *Client) IsExist(path string) bool {

	_, err := c.SFTPClient.Stat(path)
	return err == nil
}

//Md5File 检查远程是文件是否存在
func (c *Client) Md5File(path string) string {
	if c.IsNotExist(path) {
		return ""
	}
	b, err := c.Output("md5sum " + path)
	if err != nil {
		return ""
	}
	return string(bytes.Split(b, []byte{' '})[0])

}