/*
 * Copyright 2016-2018 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_MESSAGEROUTEROBSERVERINTERFACE_H_
#define ALEXA_CLIENT_SDK_ACL_INCLUDE_ACL_TRANSPORT_MESSAGEROUTEROBSERVERINTERFACE_H_

#include <memory>
#include <AVSCommon/SDKInterfaces/ConnectionStatusObserverInterface.h>

namespace alexaClientSDK {
namespace acl {

/**
 * This interface class allows notifications from a MessageRouter object (or any derived class),
 * while not adding to the observer's public interface.  This is achieved by a friend relationship.
 * The MessageRouterObserverInterface will be notified when either the connection status changes,
 * or when a message arrives from AVS.
 */
class MessageRouterObserverInterface {
public:
    /**
     * Destructor.
     */
    virtual ~MessageRouterObserverInterface() = default;

private:
    /**
     * This function will be called when the connection status changes.
     *
     * @param status The current status of the connection.
     * @param reason The reason the connection status changed.
     */
    virtual void onConnectionStatusChanged(
        const avsCommon::sdkInterfaces::ConnectionStatusObserverInterface::Status status,
        const avsCommon::sdkInterfaces::ConnectionStatusObserverInterface::ChangedReason reason) = 0;

    /**
     * This function will be called when a Message arrives from AVS.
     *
     * @param contextId The contextId of the AVS message, which is used when acquiring attachments.
     * @param message The AVS message that has been received.
     */
    virtual void receive(const std::string& contextId, const std::string& message) = 0;

    /// The friend declaration.
    friend class MessageRouter;
};

}  // namespace acl
}  // namespace alexaClientSDK

#endif  // ALEXA_CLIENT_SDK_ACL_INCLUDE_ACL_TRANSPORT_MESSAGEROUTEROBSERVERINTERFACE_H_