sopimg.go

package sopimg

import (
	"bytes"
	"crypto/md5"
	"encoding/base64"
	"encoding/hex"
	"errors"
	"image"
	"image/gif"
	"image/jpeg"
	"image/png"
	"io/ioutil"
	"math/rand"
	"os"
	"strconv"
	"strings"
	"time"
)

type SopImg interface {

	Base64ToFile(info ImgInfo) error
}

type ImgInfo struct{
	Type		string
	Base64		string
	Path		string
}

type RepImgInfo struct {
	Name 		string
	PathLong    string
	PathSmall 	string
	Postfix 	string
	Width 		int
	Height 		int
}

func (im *ImgInfo) Base64ToFile() (rep RepImgInfo,err error){
	s, err := base64.StdEncoding.DecodeString(im.Base64) //转码

	bf := bytes.NewBuffer(s)  //写入buffer

	//格式判断
	var img image.Image
	var err2 error
	var postfix string
	postfix = "jpg"
	err2 = errors.New("格式不正确")
	switch strings.ToLower(im.Type) {
	case "png":
		img,err2 = png.Decode(bf)
		postfix = "png"
		break
	case "jpg","jpeg":
		img,err2 = jpeg.Decode(bf)
		postfix = "jpg"
		break
	case "gif":
		img,err2 = gif.Decode(bf)
		postfix = "gif"
		break
	}

	//获取宽高
	var w,h int
	if err2 ==nil{
		c := img.Bounds()
		w = c.Max.X
		h = c.Max.Y
	}else{
		w = 0
		h = 0
	}


	name,p := im.GetName()

	//目录判断
	if im.Path ==""{
		im.Path = "/tmp/data/images"
	}

	//创建目录
	err = os.MkdirAll(im.Path + p,0711)
	if err != nil{
		return
	}

	fileName := name + "." + postfix
	filePath := im.Path + p + fileName

	rep.Name = fileName
	rep.PathLong = filePath
	rep.PathSmall = p + fileName
	rep.Postfix = postfix
	rep.Width = w
	rep.Height = h

	//写入文件
	err = ioutil.WriteFile(filePath, s, 0666)
	if err !=nil{
		return
	}

	return
}

func (im *ImgInfo) GetName() (name string,path string){
	ctx := md5.New()
	t := time.Now().UnixNano()
	ts := strconv.FormatInt(t,10)
	n := rand.Int63n(100000)
	ns := strconv.FormatInt(n,10)
	ctx.Write([]byte(im.Base64+ts+ns))
	name = hex.EncodeToString(ctx.Sum(nil))
	ym := time.Now().Format("200601")
	path = "/" + ym  + "/" + string([]rune(name)[10:12]) + "/" + string([]rune(name)[21:23]) + "/"
	return
}