/*
 *
 * Copyright (c) 2006 The Apache Software Foundation
 *
 * 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.
 *
 */
#ifndef _Queue_
#define _Queue_

#include <vector>
#include <queue>
#include "memory.h"
#include "apr_time.h"
#include "amqp_types.h"
#include "Binding.h"
#include "ConnectionToken.h"
#include "Consumer.h"
#include "Message.h"
#include "MonitorImpl.h"

namespace qpid {
    namespace broker {

        /**
         * Thrown when exclusive access would be violated.
         */
        struct ExclusiveAccessException{};

        /**
         * The brokers representation of an amqp queue. Messages are
         * delivered to a queue from where they can be dispatched to
         * registered consumers or be stored until dequeued or until one
         * or more consumers registers.
         */
        class Queue{
            const string name;
            const u_int32_t autodelete;
            const bool durable;
            const ConnectionToken* const owner;
            std::vector<Consumer*> consumers;
            std::queue<Binding*> bindings;
            std::queue<Message::shared_ptr> messages;
            bool queueing;
            bool dispatching;
            int next;
            mutable qpid::concurrent::MonitorImpl lock;
            apr_time_t lastUsed;
            Consumer* exclusive;

            bool startDispatching();
            bool dispatch(Message::shared_ptr& msg);

        public:
            
            typedef std::tr1::shared_ptr<Queue> shared_ptr;

            typedef std::vector<shared_ptr> vector;
	    
            Queue(const string& name, bool durable = false, u_int32_t autodelete = 0, const ConnectionToken* const owner = 0);
            ~Queue();
            /**
             * Informs the queue of a binding that should be cancelled on
             * destruction of the queue.
             */
            void bound(Binding* b);
            /**
             * Delivers a message to the queue from where it will be
             * dispatched to immediately to a consumer if one is
             * available or stored for dequeue or later dispatch if
             * not.
             */
            void deliver(Message::shared_ptr& msg);
            /**
             * Dispatch any queued messages providing there are
             * consumers for them. Only one thread can be dispatching
             * at any time, but this method (rather than the caller)
             * is responsible for ensuring that.
             */
            void dispatch();
            void consume(Consumer* c, bool exclusive = false);
            void cancel(Consumer* c);
            Message::shared_ptr dequeue();
            u_int32_t purge();
            u_int32_t getMessageCount() const;
            u_int32_t getConsumerCount() const;
            inline const string& getName() const { return name; }
            inline const bool isExclusiveOwner(const ConnectionToken* const o) const { return o == owner; }
            inline bool hasExclusiveConsumer() const { return exclusive; }
            bool canAutoDelete() const;
        };
    }
}


#endif
