// Copyright 2021 The casbin Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package casdoorsdk

import (
	"fmt"

	"github.com/golang-jwt/jwt/v4"
)

type Claims struct {
	User
	AccessToken string `json:"accessToken"`
	jwt.RegisteredClaims
}

func ParseJwtToken(token string) (*Claims, error) {
	t, err := jwt.ParseWithClaims(token, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}

		publicKey, err := jwt.ParseRSAPublicKeyFromPEM([]byte(authConfig.Certificate))
		if err != nil {
			return nil, err
		}

		return publicKey, nil
	})

	if t != nil {
		if claims, ok := t.Claims.(*Claims); ok && t.Valid {
			return claims, nil
		}
	}

	return nil, err
}