/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2016 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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 org.keycloak.authorization.util;

import org.keycloak.jose.jws.JWSInput;
import org.keycloak.jose.jws.crypto.RSAProvider;
import org.keycloak.models.KeycloakContext;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.RealmModel;
import org.keycloak.representations.AccessToken;
import org.keycloak.services.ErrorResponseException;
import org.keycloak.services.managers.AppAuthManager;
import org.keycloak.services.managers.AuthenticationManager.AuthResult;

import javax.ws.rs.core.Response.Status;
import java.security.PublicKey;

/**
 * @author <a href="mailto:psilva@redhat.com">Pedro Igor</a>
 */
public class Tokens {

    public static AccessToken getAccessToken(KeycloakSession keycloakSession) {
        AppAuthManager authManager = new AppAuthManager();
        KeycloakContext context = keycloakSession.getContext();
        AuthResult authResult = authManager.authenticateBearerToken(keycloakSession, context.getRealm(), context.getUri(), context.getConnection(), context.getRequestHeaders());

        if (authResult != null) {
            return authResult.getToken();
        }

        return null;
    }

    public static String getAccessTokenAsString(KeycloakSession keycloakSession) {
        AppAuthManager authManager = new AppAuthManager();

        return authManager.extractAuthorizationHeaderToken(keycloakSession.getContext().getRequestHeaders());
    }

    public static boolean verifySignature(KeycloakSession keycloakSession, RealmModel realm, String token) {
        try {
            JWSInput jws = new JWSInput(token);
            PublicKey publicKey = keycloakSession.keys().getPublicKey(realm, jws.getHeader().getKeyId());
            return RSAProvider.verify(jws, publicKey);
        } catch (Exception e) {
            throw new ErrorResponseException("invalid_signature", "Unexpected error while validating signature.", Status.INTERNAL_SERVER_ERROR);
        }
    }
}
