package utils

import (
    "encoding/base64"
    "errors"
    uuid "github.com/iris-contrib/go.uuid"
    "github.com/kataras/iris/v12"
    "io"
    "mime/multipart"
    "os"
    "path/filepath"
    "strings"
    "time"
)

// client version and secret, it should be from client side
const (
    UploadDir    string = "./public/upload/"
    UrlBase      string = "/upload/"
)

// DstFile 文件
type DstFile struct {
    Name string `json:"name"`
    Src  string `json:"src"`
}


func UploadFile(ctx iris.Context) (*DstFile,error){
    file ,info ,err := ctx.FormFile("uploadfile")
    if err != nil {
        return nil ,err
    }
    defer file.Close()
    
    oldFileName := info.Filename
    destFile, url := GenerateNewFileName(oldFileName)
    
    out, err := os.OpenFile(destFile, os.O_WRONLY|os.O_CREATE, 0666)
    if err != nil{
        return nil, err
    }
    
    defer out.Close()
    _ ,err = io.Copy(out,file)
    if err != nil {
        return nil, err
    }
    
    outfile := &DstFile{Name: oldFileName ,Src:url }
    
    return outfile, nil
}

func UploadFileBase64(ctx iris.Context) (*DstFile,error){
    base64StrRaw := ctx.FormValue("base64")
    if base64StrRaw == "" && len(base64StrRaw) <= 8 {
        return nil, errors.New("文件错误")
    }
    
    index := strings.Index(base64StrRaw, ";")
    base64Str := base64StrRaw[index+8:]
    
    destByte, err := base64.StdEncoding.DecodeString(base64Str)
    if err != nil {
        return nil, err
    }
    
    suffix := base64StrRaw[11:index]
    
    oldFileName := "old."+suffix
    destFile, url := GenerateNewFileName(oldFileName)
    
    out, err := os.OpenFile(destFile, os.O_WRONLY|os.O_CREATE, 0666)
    if err != nil{
        return nil, err
    }
    
    defer out.Close()
    _ ,err = out.Write(destByte)
    if err != nil {
        return nil, err
    }
    
    outfile := &DstFile{Name: oldFileName ,Src:url }
    
    return outfile, nil
}

// UploadMultiFiles Upload Multi Files
func UploadMultiFiles(ctx iris.Context)(int, []DstFile, error){
    outFiles := []DstFile{}
    
    maxSize := ctx.Application().ConfigurationReadOnly().GetPostMaxMemory()
    
    err := ctx.Request().ParseMultipartForm(maxSize)
    if err != nil {
        return 0 , outFiles, err
    }
    
    form     := ctx.Request().MultipartForm
    files    := form.File["files[]"]
    count    := len(files)
    
    failures := 0
    dstIndex := 1
    
    for _, file := range files {
        url, err := SaveUploadFile(file)
        if err != nil {
            failures++
        }else{
            out := DstFile{Name: file.Filename ,Src:url}
            outFiles = append(outFiles, out)
            dstIndex++
        }
    }
    
    num := count - failures
    
    return  num ,outFiles ,nil
}

func SaveUploadFile(fh *multipart.FileHeader)(string, error){
    src ,err := fh.Open()
    if err != nil {
        return "" ,err
    }
    defer src.Close()
    
    oldFileName := fh.Filename
    srcFile, urlFile := GenerateNewFileName(oldFileName)
    
    out, err := os.OpenFile(srcFile ,os.O_WRONLY|os.O_CREATE ,os.FileMode(0666))
    if err != nil {
        return "" ,err
    }
    
    defer out.Close()
    
    _, err = io.Copy(out, src)
    
    return urlFile, err
}

// BeforeSave Before Save
func BeforeSave(ctx iris.Context ,file *multipart.FileHeader){
    ip := ctx.RemoteAddr()
    ip = strings.Replace(ip ,"." ,"-" ,-1)
    ip = strings.Replace(ip ,":" ,"-" ,-1)
    
    file.Filename = ip + "-" + file.Filename
}

// CreateDateDir Create date directory
func CreateDateDir() (srcPath, urlPath string) {
    folderName := time.Now().Format("20060102")
    src  := filepath.Join(UploadDir, folderName)
    url  := filepath.Join(UrlBase, folderName)
    _, err := os.Stat(srcPath)
    if os.IsNotExist(err ){
        _ = os.Mkdir(src, os.ModePerm)
        _ = os.Chmod(src, os.ModePerm)
    }
    
    return src ,url
}

// GenerateNewFileName Generate new file name
func GenerateNewFileName(oldFileName string) (srcPath, urlPath string) {
    u1, _ := uuid.NewV4()
    newFileName := u1.String()
    src , url := CreateDateDir()
    
    dotIndex := strings.LastIndex(oldFileName, ".")
    if dotIndex != -1 && dotIndex != 0 {
        newFileName += oldFileName[dotIndex:]
    }
    
    src = filepath.Join(src, newFileName)
    url = filepath.Join(url, newFileName)
    
    return src, url
}