package collections

import (
    "fmt"
    "time"

    "github.com/golang-jwt/jwt/v5"
)

var hmacSampleSecret = []byte("my_eyjwt_secret")

type TokenMap struct {
    Type     string
    Nbf      int64
    Username string
    UserId   int
    Exp      int64
}

// 生成account token(认证令牌)
func GenerateAccountToken(username string, userId int) string {
    mapClaims := jwt.MapClaims{
        "type":     "account",
        "nbf":      time.Now().Unix(),
        "username": username,
        "userId":   userId,
        "exp":      time.Now().Add(time.Hour * 24 * 7).Unix(),
    }
    return generateJwtToken(mapClaims)
}

// 生成refresh token(刷新令牌)
func GenerateRefreshToken(username string, userId int) string {
    mapClaims := jwt.MapClaims{
        "type":     "refresh",
        "nbf":      time.Now().Unix(),
        "username": username,
        "userId":   userId,
        "exp":      time.Now().Add(time.Hour * 24 * 14).Unix(),
    }
    return generateJwtToken(mapClaims)
}

func generateJwtToken(mapClaims jwt.MapClaims) string {
    token := jwt.NewWithClaims(jwt.SigningMethodHS256, mapClaims)
    tokenString, err := token.SignedString(hmacSampleSecret)
    if err != nil {
        panic(err)
    }
    return tokenString
}

// 解析token信息
func ParseJwtToken(tokenString string) (TokenMap, error) {
    // 会自动检测nbf生效开始时间， exp为结束时间, 过期了会err
    token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
        // Don't forget to validate the alg is what you expect:
        if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
            return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
        }

        return hmacSampleSecret, nil
    })
    if err != nil {
        return TokenMap{}, err
    }

    if claims, ok := token.Claims.(jwt.MapClaims); ok {
        fmt.Println(claims["type"])
        return TokenMap{
            Type:     claims["type"].(string),
            Nbf:      int64(claims["nbf"].(float64)),
            Username: claims["username"].(string),
            UserId:   int(claims["userId"].(float64)),
            Exp:      int64(claims["exp"].(float64)),
        }, nil
    }
    return TokenMap{}, err
}