/*
 * Copyright 2012-2013 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
 *
 *      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.springframework.security.oauth2.provider.approval;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * @author Dave Syer
 * 
 */
public class InMemoryApprovalStore implements ApprovalStore {

	private ConcurrentMap<Key, Collection<Approval>> map = new ConcurrentHashMap<Key, Collection<Approval>>();

	@Override
	public boolean addApprovals(Collection<Approval> approvals) {
		for (Approval approval : approvals) {
			Collection<Approval> collection = getApprovals(approval);
			collection.add(approval);
		}
		return true;
	}

	@Override
	public boolean revokeApprovals(Collection<Approval> approvals) {
		boolean success = true;
		for (Approval approval : approvals) {
			Collection<Approval> collection = getApprovals(approval);
			boolean removed = collection.remove(approval);
			if (!removed) {
				success = false;
			}
		}
		return success;
	}

	private Collection<Approval> getApprovals(Approval approval) {
		Key key = new Key(approval.getUserId(), approval.getClientId());
		if (!map.containsKey(key)) {
			map.putIfAbsent(key, new HashSet<Approval>());
		}
		return map.get(key);
	}

	@Override
	public Collection<Approval> getApprovals(String userId, String clientId) {
		Approval approval = new Approval();
		approval.setUserId(userId);
		approval.setClientId(clientId);
		return Collections.unmodifiableCollection(getApprovals(approval));
	}
	
	public void clear() {
		map.clear();
	}

	private static class Key {

		String userId;

		String clientId;

		public Key(String userId, String clientId) {
			this.userId = userId;
			this.clientId = clientId;
		}

		@Override
		public int hashCode() {
			final int prime = 31;
			int result = 1;
			result = prime * result + ((clientId == null) ? 0 : clientId.hashCode());
			result = prime * result + ((userId == null) ? 0 : userId.hashCode());
			return result;
		}

		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			Key other = (Key) obj;
			if (clientId == null) {
				if (other.clientId != null)
					return false;
			}
			else if (!clientId.equals(other.clientId))
				return false;
			if (userId == null) {
				if (other.userId != null)
					return false;
			}
			else if (!userId.equals(other.userId))
				return false;
			return true;
		}

	}

}