package jwt

import (
	"errors"
	"fmt"
	"log"
	"time"

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

func GetClaimsString(claims jwt.MapClaims, key string) string {
	if subject, ok := claims[key]; ok {
		if value, ok := subject.(string); ok {
			return value
		}
	}
	return ""
}
func GetClaimsStringPtr(claims jwt.MapClaims, key string) *string {
	if subject, ok := claims[key]; ok {
		if value, ok := subject.(string); ok {
			return &value
		}
	}
	return nil
}
func GetClaimsInt64Ptr(claims jwt.MapClaims, key string) *int64 {
	if subject, ok := claims[key]; ok {
		if value, ok := subject.(int64); ok {
			return &value
		}
	}
	return nil
}

func GetClaimsIssuerAndExpiresAt2(claims jwt.MapClaims) (issuer *string, expiresAt *jwt.NumericDate) {
	issuer = GetClaimsStringPtr(claims, "iss")
	exp := GetClaimsInt64Ptr(claims, "exp")
	if exp != nil {
		expiresAt = jwt.NewNumericDate(time.Unix(*exp, 0))
	}
	return
}

func GetClaimsIssuerAndExpiresAt(claims jwt.Claims) (issuer *string, expiresAt *jwt.NumericDate) {
	mapClaims, _ := claims.(jwt.MapClaims)
	return GetClaimsIssuerAndExpiresAt2(mapClaims)
}

func ParseJwtToken(jwtToken *string, secret string) (jwt.Claims, error) {
	token, err := jwt.Parse(*jwtToken, func(token *jwt.Token) (any, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method %v", token.Header["alg"])
		}
		return []byte(secret), nil
	})

	if err != nil {
		log.Println("jwt parse err:", err)
		return nil, err
	}

	if token.Valid {
		return token.Claims, nil
	}

	return nil, errors.New("invalid jwt token")
}

// self jwt token, no need to check activated
func ParseJwtTokenWithClaims(jwtToken *string, secret string) (*CustomClaims, error) {
	claims := &CustomClaims{}

	token, err := jwt.ParseWithClaims(*jwtToken, claims, func(token *jwt.Token) (any, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method %v", token.Header["alg"])
		}
		return []byte(secret), nil
	})

	if err != nil {
		return nil, err // token is expired by
	}

	if !token.Valid {
		return nil, errors.New("invalid jwt")
	}

	// if token.Claims.Valid().Error()

	return claims, nil
}