/*
 * 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.axis2.description;

import org.apache.axiom.util.UIDGenerator;
import org.apache.neethi.Policy;
import org.apache.neethi.PolicyComponent;
import org.apache.neethi.PolicyReference;

import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicLong;

public class PolicySubject {
    private static final AtomicLong VERSION_COUNTER = new AtomicLong();
    private volatile long version = VERSION_COUNTER.incrementAndGet();
    @Deprecated
    private Date lastUpdatedTime = new Date();
    
    private ConcurrentHashMap<String, PolicyComponent> attachedPolicyComponents = new ConcurrentHashMap<String, PolicyComponent>();

    public void attachPolicy(Policy policy) {
        String key = policy.getName();
        if (key == null) {
            key = policy.getId();
            if (key == null) {
                key = UIDGenerator.generateUID();
                policy.setId(key);
            }
        }
        attachPolicyComponent(key, policy);
    }

    public void attachPolicyReference(PolicyReference reference) {
        attachedPolicyComponents.put(reference.getURI(), reference);
        setLastUpdatedTime(new Date()); 
    }

    public void attachPolicyComponents(List<PolicyComponent> policyComponents) {
        for (Iterator<PolicyComponent> iterator = policyComponents.iterator(); iterator
                .hasNext();) {
            attachPolicyComponent((PolicyComponent) iterator.next());
        }
    }

    public void attachPolicyComponent(PolicyComponent policyComponent) {
        if (policyComponent instanceof Policy) {
            attachPolicy((Policy) policyComponent);
        } else if (policyComponent instanceof PolicyReference) {
            attachPolicyReference((PolicyReference) policyComponent);
        } else {
            throw new IllegalArgumentException(
                    "Invalid top level policy component type");
        }

    }

    public void attachPolicyComponent(String key,
            PolicyComponent policyComponent) {
        attachedPolicyComponents.put(key, policyComponent);
        setLastUpdatedTime(new Date());
    }

    public PolicyComponent getAttachedPolicyComponent(String key) {
        return (PolicyComponent) attachedPolicyComponents.get(key);

    }

    public Collection<PolicyComponent> getAttachedPolicyComponents() {
        return attachedPolicyComponents.values();
    }

    public void updatePolicy(Policy policy) {
        String key = (policy.getName() != null) ? policy.getName() : policy
                .getId();
        if (key == null) {
            throw new IllegalArgumentException(
                    "policy doesn't have a name or an id ");
        }
        attachedPolicyComponents.put(key, policy);
        setLastUpdatedTime(new Date());
    }

    public void detachPolicyComponent(String key) {
        attachedPolicyComponents.remove(key);
        setLastUpdatedTime(new Date());
    }

    public void clear() {
        attachedPolicyComponents.clear();
        setLastUpdatedTime(new Date());
    }

    public Date getLastUpdatedTime() {
        return lastUpdatedTime;
    }

    public void setLastUpdatedTime(Date lastUpdatedTime) {
        this.lastUpdatedTime = lastUpdatedTime;
        this.version = VERSION_COUNTER.incrementAndGet();
    }

    /**
     * Returns the current version of the policy set, represented by a
     * monotonically increasing number. This version number changes every
     * time a policy is attached, detached, updated, or cleared.
     *
     * @return the current policy version
     */
    public long getVersion() {
        return version;
    }
}
