/*
 * Copyright 2017-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *     http://aws.amazon.com/apache2.0/
 *
 * or in the "license" file accompanying this file. This file 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 ALEXA_CLIENT_SDK_ACL_INCLUDE_ACL_TRANSPORT_MESSAGEROUTERINTERFACE_H_
#define ALEXA_CLIENT_SDK_ACL_INCLUDE_ACL_TRANSPORT_MESSAGEROUTERINTERFACE_H_

#include <memory>
#include <string>
#include <utility>

#include "AVSCommon/Utils/Threading/Executor.h"
#include "AVSCommon/Utils/RequiresShutdown.h"
#include "AVSCommon/AVS/MessageRequest.h"
#include "AVSCommon/SDKInterfaces/MessageSenderInterface.h"

#include "ACL/Transport/MessageRouterObserverInterface.h"
#include "ACL/Transport/TransportInterface.h"
#include "ACL/Transport/TransportObserverInterface.h"

namespace alexaClientSDK {
namespace acl {

/**
 * This specifies the interface to manage an actual connection over some medium to AVS.
 *
 * Implementations of this class are required to be thread-safe.
 */
class MessageRouterInterface
        : public avsCommon::sdkInterfaces::MessageSenderInterface
        , public avsCommon::utils::RequiresShutdown {
public:
    /// Alias to a connection status and changed reason pair.
    using ConnectionStatus = std::pair<
        avsCommon::sdkInterfaces::ConnectionStatusObserverInterface::Status,
        avsCommon::sdkInterfaces::ConnectionStatusObserverInterface::ChangedReason>;

    /**
     * Constructor.
     */
    MessageRouterInterface(const std::string& name);

    /**
     * Begin the process of establishing an AVS connection.
     * If the underlying implementation is already connected, or is in the process of changing its connection state,
     * this function should do nothing.
     */
    virtual void enable() = 0;

    /**
     * Close the AVS connection.
     * If the underlying implementation is not connected, or is in the process of changing its connection state,
     * this function should do nothing.
     *
     */
    virtual void disable() = 0;

    /**
     * Queries the status of the connection.
     *
     * @return Returns the connection status and changed reason pair of the underlying implementation.
     */
    virtual ConnectionStatus getConnectionStatus() = 0;

    /**
     * Set the URL endpoint for the AVS connection.  Calling this function with a new value will cause the
     * current active connection to be closed, and a new one opened to the new endpoint.
     * @param avsEndpoint The URL for the new AVS endpoint.
     */
    virtual void setAVSEndpoint(const std::string& avsEndpoint) = 0;

    /**
     * Set the observer to this object.
     * @param observer An observer to this class, which will be notified when the connection status changes,
     * and when messages arrive from AVS.
     */
    virtual void setObserver(std::shared_ptr<MessageRouterObserverInterface> observer) = 0;

    /**
     * Destructor.
     */
    virtual ~MessageRouterInterface() = default;
};

inline MessageRouterInterface::MessageRouterInterface(const std::string& name) : RequiresShutdown(name) {
}

}  // namespace acl
}  // namespace alexaClientSDK

#endif  // ALEXA_CLIENT_SDK_ACL_INCLUDE_ACL_TRANSPORT_MESSAGEROUTERINTERFACE_H_