ArOZMinecraftServer/mod/mc/skin.go

package mc

import (
	"encoding/base64"
	"encoding/json"
	"log"
	"os"
	"regexp"
)

//DownloadSkin is exported function
func (mc *Handler) DownloadSkin() {
	if _, err := os.Stat(mc.savePath + "/" + mc.UUID + ".png"); os.IsNotExist(err) {
		if IsValidUUID(mc.UUID) {
			resp := httpReq("https://sessionserver.mojang.com/session/minecraft/profile/" + mc.UUID)
			var profileArray profile
			json.Unmarshal(resp, &profileArray)
			if len(profileArray.Error) > 0 {
				log.Println("Error when reading profiles. Download aborted.")
				copy("default_skin.png", mc.savePath+"/"+mc.UUID+".png")
			} else {
				if len(profileArray.Properties) > 0 {
					decoded, _ := base64.URLEncoding.DecodeString(profileArray.Properties[0].Value)
					var textureArray texture
					json.Unmarshal([]byte(decoded), &textureArray)
					downloadFile(mc.savePath+"/"+mc.UUID+".png", textureArray.Textures.SKIN.URL)
				} else {
					copy("default_skin.png", mc.savePath+"/"+mc.UUID+".png")
					log.Println("Error when reading profiles. Download aborted.")
				}
			}
		} else {
			log.Println("Invaild UUID... Using fallback skin")
			copy("default_skin.png", mc.savePath+"/"+mc.UUID+".png")
		}
	} else {
		//log.Println("Skin exists, not downloading")
	}
}

//vaild UUID
//https://stackoverflow.com/questions/25051675/how-to-validate-uuid-v4-in-go
func IsValidUUID(uuid string) bool {
	r := regexp.MustCompile("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-4[a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12}$")
	return r.MatchString(uuid)
}