package utils

import (
	"errors"
	"fmt"
	"github.com/golang-jwt/jwt/v5"
	"github.com/google/uuid"
	"os"
	"relay-server/model"
)

func GenerateToken(userID uuid.UUID, username string) (string, error) {

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
		"user_id":  userID,
		"username": username,
	})
	signedToken, err := token.SignedString([]byte(os.Getenv("JWT_SECRET")))
	if err != nil {
		return "", NewError(ErrInternal, "Failed to generate token", err)
	}
	return signedToken, nil
}

func ValidateToken(tokenString string) (*model.UserClaims, error) {
	secretKey := os.Getenv("JWT_SECRET")

	// Parse the token
	token, err := jwt.ParseWithClaims(tokenString, &model.UserClaims{}, func(token *jwt.Token) (interface{}, error) {
		// Validate the signing method
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}

		return []byte(secretKey), nil
	})

	if err != nil {
		return nil, fmt.Errorf("failed to parse token: %v", err)
	}

	// Check if the token is valid
	if !token.Valid {
		return nil, errors.New("invalid token")
	}

	// Type assert the claims
	claims, ok := token.Claims.(*model.UserClaims)
	if !ok {
		return nil, errors.New("failed to parse claims")
	}

	return claims, nil
}