/*
This file is part of Telegram Desktop,
the official desktop version of Telegram messaging app, see https://telegram.org

Telegram Desktop 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 3 of the License, or
(at your option) any later version.

It 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.

In addition, as a special exception, the copyright holders give permission
to link the code of portions of this program with the OpenSSL library.

Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
*/
#include "stdafx.h"
#include "core/observer.h"

namespace Notify {
namespace {

using StartCallbacksList = QVector<StartObservedEventCallback>;
using FinishCallbacksList = QVector<FinishObservedEventCallback>;
NeverFreedPointer<StartCallbacksList> StartCallbacks;
NeverFreedPointer<FinishCallbacksList> FinishCallbacks;
UnregisterObserverCallback UnregisterCallbacks[256]/* = { nullptr }*/;

} // namespace

void startObservers() {
	if (!StartCallbacks) return;

	for (auto &callback : *StartCallbacks) {
		callback();
	}
}

void finishObservers() {
	if (!FinishCallbacks) return;

	for (auto &callback : *FinishCallbacks) {
		callback();
	}
	StartCallbacks.clear();
	FinishCallbacks.clear();
}

ObservedEventRegistrator::ObservedEventRegistrator(ObservedEvent event
, StartObservedEventCallback startCallback
, FinishObservedEventCallback finishCallback
, UnregisterObserverCallback unregisterCallback) {
	StartCallbacks.makeIfNull();
	StartCallbacks->push_back(startCallback);

	FinishCallbacks.makeIfNull();
	FinishCallbacks->push_back(finishCallback);

	UnregisterCallbacks[event] = unregisterCallback;
}

// Observer base interface.
Observer::~Observer() {
	for_const (auto connection, _connections) {
		unregisterObserver(connection);
	}
}

void Observer::observerRegistered(ConnectionId connection) {
	_connections.push_back(connection);
}

void unregisterObserver(ConnectionId connection) {
	auto event = static_cast<ObservedEvent>(connection >> 24);
	auto connectionIndex = int(connection & 0x00FFFFFFU) - 1;
	if (connectionIndex >= 0 && UnregisterCallbacks[event]) {
		UnregisterCallbacks[event](connectionIndex);
	}
}

namespace internal {

void observerRegisteredDefault(Observer *observer, ConnectionId connection) {
	observer->observerRegistered(connection);
}

} // namespace internal
} // namespace Notify