/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.syncope.core.spring.security;

import java.util.Date;
import javax.annotation.Resource;
import org.apache.cxf.rs.security.jose.jwt.JwtClaims;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.CredentialsExpiredException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;

/**
 * Attempts to authenticate the passed {@link JWTAuthentication} object, returning a fully populated
 * {@link Authentication} object (including granted authorities) if successful.
 */
public class JWTAuthenticationProvider implements AuthenticationProvider {

    @Resource(name = "jwtIssuer")
    private String jwtIssuer;

    @Autowired
    private AuthDataAccessor dataAccessor;

    @Override
    public Authentication authenticate(final Authentication authentication) throws AuthenticationException {
        final JWTAuthentication jwtAuthentication = (JWTAuthentication) authentication;

        AuthContextUtils.execWithAuthContext(
                jwtAuthentication.getDetails().getDomain(),
                new AuthContextUtils.Executable<Void>() {

            @Override
            public Void exec() {
                jwtAuthentication.getAuthorities().addAll(dataAccessor.authenticate(jwtAuthentication));
                return null;
            }
        });

        JwtClaims claims = jwtAuthentication.getClaims();
        Long referenceTime = new Date().getTime();

        Long expiryTime = claims.getExpiryTime();
        if (expiryTime == null || expiryTime < referenceTime) {
            dataAccessor.removeExpired(claims.getTokenId());
            throw new CredentialsExpiredException("JWT is expired");
        }

        Long notBefore = claims.getNotBefore();
        if (notBefore == null || notBefore > referenceTime) {
            throw new CredentialsExpiredException("JWT not valid yet");
        }

        if (!jwtIssuer.equals(claims.getIssuer())) {
            throw new BadCredentialsException("Invalid JWT issuer");
        }

        jwtAuthentication.setAuthenticated(true);
        return jwtAuthentication;
    }

    @Override
    public boolean supports(final Class<?> authentication) {
        return JWTAuthentication.class.isAssignableFrom(authentication);
    }
}