/**
 * 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.activemq.security;


import java.security.Principal;
import java.util.Collections;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.apache.activemq.command.ActiveMQDestination;

/**
 * Used to cache up authorizations so that subsequent requests are faster.
 *
 *
 */
public abstract class SecurityContext {

    static final String WILDCARD = "*";

    static final Principal WILDCARD_PRINCIPAL = () -> WILDCARD;

    public static final SecurityContext BROKER_SECURITY_CONTEXT = new SecurityContext("ActiveMQBroker") {
        @Override
        public boolean isBrokerContext() {
            return true;
        }

        @Override
        public Set<Principal> getPrincipals() {
            return Collections.emptySet();
        }
    };

    final String userName;

    final ConcurrentMap<ActiveMQDestination, ActiveMQDestination> authorizedWriteDests = new ConcurrentHashMap<ActiveMQDestination, ActiveMQDestination>();

    public SecurityContext(String userName) {
        this.userName = userName;
    }

    public static boolean isWildcardPrincipal(Object principal) {
        return principal == WILDCARD_PRINCIPAL;
    }

    public static boolean containsWildcardPrincipal(Set<?> principals) {
        return principals.contains(WILDCARD_PRINCIPAL);
    }

    public boolean isInOneOf(Set<?> allowedPrincipals) {
        // Wildcard Principal is a special principal that allows all
        // Check for that first using an identify check. This is
        // a fast check that allows us to avoid iterating if true
        if (containsWildcardPrincipal(allowedPrincipals)) {
            return true;
        }

        // Iterate over all the principals to see if there are matches
        for (Object allowedPrincipal : allowedPrincipals) {
            if (contains(allowedPrincipal)) {
                return true;
            }
        }
        return false;
    }

    public abstract Set<Principal> getPrincipals();

    public boolean contains(Object principal) {
        Set<Principal> principals = getPrincipals();
        return principals != null && principals.contains(principal);
    }

    public String getUserName() {
        return userName;
    }

    public ConcurrentMap<ActiveMQDestination, ActiveMQDestination> getAuthorizedWriteDests() {
        return authorizedWriteDests;
    }

    public boolean isBrokerContext() {
        return false;
    }
}
