package utils

import (
	"os"
	"time"

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

type SubscriberTokenClaims struct {
	Email string `json:"email"`
	jwt.RegisteredClaims
}

// GenerateSubscriberToken creates a signed token for a subscriber email, expires in `ttl` minutes
func GenerateSubscriberToken(email string, ttlMinutes int) (string, error) {
	if ttlMinutes <= 0 {
		ttlMinutes = 60
	}
	now := time.Now()
	claims := &SubscriberTokenClaims{
		Email: email,
		RegisteredClaims: jwt.RegisteredClaims{
			IssuedAt:  jwt.NewNumericDate(now),
			ExpiresAt: jwt.NewNumericDate(now.Add(time.Duration(ttlMinutes) * time.Minute)),
			Issuer:    "fotbal-club",
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(getJWTSecret()))
}

// ParseSubscriberToken validates and returns the email embedded in the token
func ParseSubscriberToken(tokenString string) (string, error) {
	token, err := jwt.ParseWithClaims(tokenString, &SubscriberTokenClaims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(getJWTSecret()), nil
	})
	if err != nil {
		return "", err
	}
	if claims, ok := token.Claims.(*SubscriberTokenClaims); ok && token.Valid {
		return claims.Email, nil
	}
	return "", jwt.ErrTokenMalformed
}

func getJWTSecret() string {
	s := os.Getenv("JWT_SECRET")
	if s == "" {
		return "default-secret-key-change-in-production"
	}
	return s
}