#include "Server.hpp"

#include "EpistmoolServer/Protocol/Error.hpp"
#include "EpistmoolServer/ServerProperties.hpp"

#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonValue>
#include <QLatin1String>
#include <QVersionNumber>

using namespace Epistmool::Server;

// TODO structured error handling similar to messages
class Server::Private
{
public:
	static bool messageHeader(QJsonObject& msg, SessionId sessionId, int id)
	{
		msg.insert("session", sessionId.index);
		msg.insert("id", id);
		return true;
	}

	static bool messageErrInvalidVersion(QJsonObject& msg)
	{
		QJsonObject error;
		error.insert("type", ProtocolErrors::kUnsupportedVersion.name);
		error.insert("supportedVersion", ServerProperties::kVersion.toString());

		msg.insert("error", error);

		return true;
	}
};

Server::Server(QObject* parent)
	: QObject(parent)
{
	mConnectionManager.setLocalConnectionsEnabled(true);

	connect(&mConnectionManager, &ConnectionManager::messageRecieved, this, &Server::onMessage);
	connect(&mConnectionManager, &ConnectionManager::connectionDropped, &mSessionManager, &SessionManager::dropConnection);
}

void Server::onMessage(const QJsonDocument& message, ConnectionId connId)
{
	if (!message.isObject()) return;
	auto root = message.object();

	// Extract as empty string if non-existent
	auto versionString = root.value("version").toString();

	int id = root.value("id").toInt();

	SessionId sessionId;
	if (auto index = root.value("session").toInt(-1); index == -1) {
		sessionId = SessionId::makeInvalid();
	} else {
		sessionId.index = index;
	}

	auto version = [&]() -> QVersionNumber {
		if (versionString.isEmpty()) {
			return QVersionNumber();
		} else {
			return QVersionNumber::fromString(versionString).normalized();
		}
	}();
	if (version.isNull() || version >= ServerProperties::kVersion) {
		qWarning() << "Message recieved with invalid version " << versionString;

		QJsonObject msg;
		Private::messageHeader(msg, sessionId, id);
		Private::messageErrInvalidVersion(msg);
		mConnectionManager.replyMessage(connId, QJsonDocument(msg));

		return;
	}

	Session* session;
	if (sessionId.isInvalid()) {
		session = nullptr;
	} else {
		session = mSessionManager.findSession(sessionId);
	}

	// TODO dispatch message
}