/*
 * Copyright 2023 the original author or authors.
 *
 * 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
 *
 *      https://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 com.hclsoftware.sso.kerberos.config;

import org.springframework.ldap.core.DirContextOperations;
import org.springframework.ldap.core.DistinguishedName;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.AuthorityUtils;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.ldap.userdetails.LdapAuthoritiesPopulator;

import java.util.ArrayList;
import java.util.Collection;

public class ActiveDirectoryLdapAuthoritiesPopulator implements LdapAuthoritiesPopulator {

    @Override
    public Collection<? extends GrantedAuthority> getGrantedAuthorities(DirContextOperations userData, String username) {
        String[] groups = userData.getStringAttributes("memberOf");

        if (groups == null) {
            return AuthorityUtils.NO_AUTHORITIES;
        }

        ArrayList<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>(
                groups.length);

        for (String group : groups) {
            authorities.add(new SimpleGrantedAuthority(new DistinguishedName(group)
                    .removeLast().getValue()));
        }

        return authorities;
    }

}
