package utils

import (
	"time"

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

type JWTManager struct {
	secret []byte
	ttl    time.Duration
}

func NewJWTManager(secret string, ttl time.Duration) *JWTManager {
	return &JWTManager{secret: []byte(secret), ttl: ttl}
}

type Claims struct {
	UserID   uint   `json:"userId"`
	Username string `json:"username"`
	Role     string `json:"role"`
	jwt.RegisteredClaims
}

func (j *JWTManager) Generate(userID uint, username, role string) (string, error) {
	now := time.Now()
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, Claims{
		UserID:   userID,
		Username: username,
		Role:     role,
		RegisteredClaims: jwt.RegisteredClaims{
			IssuedAt:  jwt.NewNumericDate(now),
			ExpiresAt: jwt.NewNumericDate(now.Add(j.ttl)),
			ID:        username + now.Format("20060102150405"),
		},
	})
	return token.SignedString(j.secret)
}

func (j *JWTManager) Parse(tokenString string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		return j.secret, nil
	})
	if err != nil {
		return nil, err
	}
	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
		return claims, nil
	}
	return nil, jwt.ErrTokenInvalidClaims
}