package service

import (
	"errors"
	"esauth"
	"esauth/pkg/repository"
	"math"
	"os"
	"time"

	"github.com/dgrijalva/jwt-go"
)

const (
	tokenTTL = 12 * time.Hour
)

type tokenClaims struct {
	jwt.StandardClaims
	UserId int64 `json:"user_id"`
}

type AuthService struct {
	repo *repository.Repository
}

func NewAuthService(repo *repository.Repository) *AuthService {
	return &AuthService{repo: repo}
}

func (s *AuthService) CreateUser(user *esauth.User) (int64, error) {
	return s.repo.CreateUser(user)
}
func (s *AuthService) SaveUser(user *esauth.User) (int64, error) {
	return s.repo.SaveUser(user)
}
func (s *AuthService) GenerateToken(userId int64) (string, error) {
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, &tokenClaims{
		jwt.StandardClaims{
			ExpiresAt: time.Now().Add(tokenTTL).Unix(),
			IssuedAt:  time.Now().Unix(),
		},
		userId,
	})
	return token.SignedString([]byte(os.Getenv("SIGN_KEY")))
}

func (s *AuthService) GenerateInfinityToken(userId int64) (string, error) {
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, &tokenClaims{
		jwt.StandardClaims{
			ExpiresAt: math.MaxInt64,
			IssuedAt:  time.Now().Unix(),
		},
		userId,
	})
	return token.SignedString([]byte(os.Getenv("SIGN_KEY")))
}

func (s *AuthService) ParseToken(accessToken string) (int64, error) {
	token, err := jwt.ParseWithClaims(accessToken, &tokenClaims{}, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, errors.New("invalid signing method")
		}

		return []byte(os.Getenv("SIGN_KEY")), nil
	})
	if err != nil {
		return 0, err
	}

	claims, ok := token.Claims.(*tokenClaims)
	if !ok {
		return 0, errors.New("token claims are not of type *tokenClaims")
	}

	return claims.UserId, nil
}