package main

import (
   "fmt"
   jwt "github.com/dgrijalva/jwt-go"
   "time"
)

// Claims custom token
type Claims struct {
   UserID  int32 `json:"user_id"` 
   jwt.StandardClaims
}

// CreateToken create token
func CreateToken(claims *Claims) (signedToken string, success bool) {
   claims.ExpiresAt = time.Now().Add(time.Minute * 30).Unix()
   token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
   signedToken, err := token.SignedString([]byte("secret"))
   if err != nil {
      return
   }

   success = true
   return
}

// ValidateToken validate token
func ValidateToken(signedToken string) (claims *Claims, success bool) {
   token, err := jwt.ParseWithClaims(signedToken, &Claims{},
      func(token *jwt.Token) (interface{}, error) {
         if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
            return nil, fmt.Errorf("unexpected login method %v", token.Header["alg"])
         }
         return []byte("secret"), nil
      })

   if err != nil {
      return
   }

   claims, ok := token.Claims.(*Claims)
   if ok && token.Valid {
      success = true
      return
   }

   return
}


func main(){
    var myClaim = &Claims{
       UserID: 10000,
   }
   tokenCResult,res := CreateToken(myClaim)
   if !res{
      fmt.Println("err")
      return
   }
   fmt.Println(tokenCResult)

   myClaim1,res := ValidateToken(tokenCResult)
   if !res{
      fmt.Println("fa")
      return
   }
   fmt.Println(myClaim1)
}