package file

import (
	"crypto/md5"
	"encoding/hex"
	"icloudapp.cn/tools/util"
	"io"
	"mime/multipart"
	"os"
	"path"
	"strconv"
	"strings"
	"time"
)

type Upload struct {
	Path    string
	Allowed map[string]bool
	HasHash bool
}

// FileWithErr 用于返回一组上传的文件信息
type FileWithErr struct {
	Err      error
	FileInfo *File
}

type File struct {
	//上传文件名
	Name string `json:"name"`
	//上传后文件路径
	File     string `json:"file"`
	Basename string `json:"basename"`
	//文件大小
	Size int64 `json:"size"`
	//文件Hash
	Hash string `json:"hash"`
	//文件类型
	Mine string `json:"mine"`
}

func NewUpload(dir string) *Upload {
	return &Upload{
		Path: dir,
	}
}

// 是否返回文件的hash
func (u *Upload) SetHasHash(hashash bool) {
	u.HasHash = hashash
}

// 设置上传目录
func (u *Upload) SetUploadPath(dir string) {
	u.Path = dir
}

// 设置允许的文件类型
func (u *Upload) SetAllowed(allowed map[string]bool) {
	u.Allowed = allowed
}

// 追加允许的文件类型
func (u *Upload) AppendAllow(ext string) {
	u.Allowed[ext] = true
}

// 上传单个文件
func (u *Upload) Single(file multipart.FileHeader) (*File, error) {
	res := &File{}
	extName := strings.ToLower(path.Ext(file.Filename))
	if _, ok := u.Allowed[extName]; !ok {
		return res, util.NewError("不允许的上传类型")
	}
	res.Name = file.Filename
	res.Size = file.Size
	res.Mine = file.Header.Get("Content-Type")

	if !IsDir(u.Path) {
		if err := os.MkdirAll(u.Path, 0750); err != nil {
			return nil, util.NewError("目录创建失败", u.Path)
		}
	}

	fileUnixName := strconv.FormatInt(time.Now().UnixNano(), 10)
	res.Basename = fileUnixName + extName
	savePath := path.Join(u.Path, res.Basename)
	res.File = savePath

	src, err := file.Open()
	if err != nil {
		return nil, util.NewError("文件打开失败：", err.Error())
	}
	defer src.Close()

	out, err := os.Create(savePath)
	if err != nil {
		return nil, util.NewError("文件创建失败：", err.Error())
	}
	defer out.Close()
	if u.HasHash {
		res.Hash = u.FileHash(savePath)
	}
	_, err = io.Copy(out, src)
	return res, nil
}

// Multiple 上传多个文件
func (u *Upload) Multiple(files []multipart.FileHeader) ([]*FileWithErr, error) {
	var res []*FileWithErr
	for key, file := range files {
		uploaded, err := u.Single(file)
		res[key] = &FileWithErr{Err: err, FileInfo: uploaded}
	}
	return res, nil
}

// FileHash 获取文件的hash值
func (u *Upload) FileHash(path string) string {
	file, _ := os.Open(path)
	m := md5.New()
	_, err := io.Copy(m, file)
	if err == nil {
		hash := m.Sum(nil)
		return hex.EncodeToString(hash)
	}
	return ""
}