/* Copyright (C) 2019
 *
 * This file is part of the osdev components suite
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
 */
#include "serverstate.h"

using namespace osdev::components::mqtt;

const std::string ServerState::s_identifier("ServerState");

std::atomic<StateChangeCallbackHandle> ServerState::s_nextServerStateCallbackHandle(1);

ServerState::ServerState(const IStateCallback* stateCallbackIf)
    : sig_serverStateChanged()
    , m_stateCallbackIf(stateCallbackIf)
    , m_serverStateCallbackMap()
    , m_state(StateEnum::Unknown)
{
}

ServerState::~ServerState()
{
    try {
        this->clearAllStateChangeCallbacks();
    }
    catch (...) {
    }
}

StateChangeCallbackHandle ServerState::registerStateChangeCallback(const IStateCallback::SlotStateChange& cb)
{
    const auto handle = s_nextServerStateCallbackHandle++;
    m_serverStateCallbackMap.emplace(std::piecewise_construct,
        std::make_tuple(handle),
        std::make_tuple(sig_serverStateChanged.connect(cb)));

    return handle;
}

void ServerState::unregisterStateChangeCallback(StateChangeCallbackHandle handle)
{
    m_serverStateCallbackMap.erase(handle);
}

void ServerState::clearAllStateChangeCallbacks()
{
    this->emitStateChanged(StateEnum::Unregister);
    m_serverStateCallbackMap.clear();
}

void ServerState::emitStateChanged(StateEnum newState)
{
    m_state = newState; ///< store state, to allow clients to retrieve the last received state.

    if (nullptr != m_stateCallbackIf) {
        sig_serverStateChanged(m_stateCallbackIf, newState);
    }
}

StateEnum ServerState::state() const
{
    return m_state;
}

std::string ServerState::stateCallbackClientId() const
{
    static const std::string nullId = "null";
    return (nullptr == m_stateCallbackIf) ? nullId : m_stateCallbackIf->clientId();
}