#include <QtCore/QTextCodec>
#include <openobex/obex.h>
#include "obexconnection.h"

ObexTransfer::ObexTransfer(obex_t *obex, obex_object_t *obj, QObject *parent) :
	QObject(parent), _obex(obex), _obj(obj)
{
}

void ObexTransfer::cancel()
{
	// TODO
}

ObexConnection::ObexConnection(ToqConnection *conn, QObject *parent) :
	QObject(parent), _conn(conn),
	_socket(0),
	_reconnectTimer(new QTimer(this)),
	_obex(0),
	_connected(false), _busy(false)
{
	connect(_conn, &ToqConnection::connected,
			this, &ObexConnection::handleToqConnected);
	connect(_conn, &ToqConnection::disconnected,
			this, &ObexConnection::handleToqDisconnected);

	connect(_reconnectTimer, &QTimer::timeout,
			this, &ObexConnection::tryConnect);

	_reconnectTimer->setSingleShot(true);
	_reconnectTimer->setInterval(500);

	if (_conn->isConnected()) {
		_reconnectTimer->start();
	}
}

ObexTransfer * ObexConnection::put(const QString &name, const QByteArray &data)
{
	obex_object_t *obj = OBEX_ObjectNew(_obex, OBEX_CMD_PUT);
	obex_headerdata_t hd;
	hd.bq4 = data.size();
	OBEX_ObjectAddHeader(_obex, obj, OBEX_HDR_LENGTH, hd, 4,
						 OBEX_FL_FIT_ONE_PACKET);

	QTextCodec *codec = QTextCodec::codecForName("UTF-16BE");
	QByteArray unicode = codec->fromUnicode(name);
	unicode.append("\0\0", 2); // Require null terminator
	hd.bs = reinterpret_cast<const uint8_t *>(unicode.constData());
	OBEX_ObjectAddHeader(_obex, obj, OBEX_HDR_NAME, hd, unicode.size(),
						 OBEX_FL_FIT_ONE_PACKET);

	hd.bs = reinterpret_cast<const uint8_t *>(data.constData());
	OBEX_ObjectAddHeader(_obex, obj, OBEX_HDR_BODY, hd, data.size(), 0);

	ObexTransfer *transfer = new ObexTransfer(_obex, obj, this);
	connect(transfer, &ObexTransfer::destroyed,
			this, &ObexConnection::handleTransferDestroyed);

	_pending.push_back(transfer);

	// Delay actual start of the transfer in order to give time for caller
	// to connect to signals of the returned transfer object.
	QMetaObject::invokeMethod(this, "handleNextPending", Qt::QueuedConnection);

	return transfer;
}

void ObexConnection::tryConnect()
{
	Q_ASSERT(!_socket);
	Q_ASSERT(_conn->isConnected());

	qDebug() << "Trying to make OBEX connection";

	_socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol, this);
	connect(_socket, &QBluetoothSocket::connected,
			this, &ObexConnection::handleSocketConnected);
	connect(_socket, &QBluetoothSocket::disconnected,
			this, &ObexConnection::handleSocketDisconnected);
	connect(_socket, (void (QBluetoothSocket::*)(QBluetoothSocket::SocketError))&QBluetoothSocket::error,
			this, &ObexConnection::handleSocketError);
	connect(_socket, &QBluetoothSocket::readyRead,
			this, &ObexConnection::handleSocketData);

	_socket->connectToService(_conn->address(), 4);
}

void ObexConnection::handleToqConnected()
{
	if (_socket) {
		qDebug() << "Toq just connected but OBEX connection still active";
		_socket->disconnectFromService();
		if (_socket) {
			_socket->deleteLater();
			_socket = 0;
		}
	}
	tryConnect();
}

void ObexConnection::handleToqDisconnected()
{
	_reconnectTimer->stop();
	if (_obex) {
		OBEX_Cleanup(_obex);
		_obex = 0;
	}
	if (_socket) {
		_socket->disconnectFromService();
		if (_socket) {
			_socket->deleteLater();
			_socket = 0;
		}
	}
	_connected = false;
	_busy = false;
}

void ObexConnection::handleSocketConnected()
{
	qDebug() << "OPP connected";

	_obex = OBEX_Init(OBEX_TRANS_CUSTOM, handleObexEvent, 0);
	if (!_obex) {
		qWarning() << "Could not initialize OBEX library";
		// If we fail to connect, the watch will eventually disconnect from us.
		// So there's no need to do anything.
		return;
	}

	OBEX_SetUserData(_obex, this);
	OBEX_SetTransportMTU(_obex, OBEX_MAXIMUM_MTU, OBEX_MAXIMUM_MTU);

	obex_ctrans_t trans;
	trans.connect = obexConnect;
	trans.disconnect = obexDisconnect;
	trans.listen = obexListen;
	trans.write = obexWrite;
	trans.handleinput = obexHandleInput;
	trans.customdata = _socket;
	int rc = OBEX_RegisterCTransport(_obex, &trans);
	if (rc < 0) {
		qWarning() << "Could not initialize custom OBEX transport";
		return;
	}

	obex_object_t *obj = OBEX_ObjectNew(_obex, OBEX_CMD_CONNECT);
	Q_ASSERT(obj);

	if (OBEX_Request(_obex, obj) < 0) {
		qWarning() << "Could not send OBEX_CMD_CONNECT";
		return;
	}

	_busy = true; // We're waiting for CONNECT result
}

void ObexConnection::handleSocketDisconnected()
{
	qDebug() << "OPP disconnected";
	if (_obex) {
		OBEX_Cleanup(_obex);
		_obex = 0;
	}
	if (_socket) {
		_socket->deleteLater();
		_socket = 0;
	}
	emit disconnected();
	if (_conn->isConnected()) {
		qDebug() << "OPP socket died but main socket still alive, retrying connection";
		_reconnectTimer->start();
	}
	_connected = false;
	_busy = false;
}

void ObexConnection::handleSocketError(QBluetoothSocket::SocketError error)
{
	qWarning() << "OPP socket error" << error;
}

void ObexConnection::handleSocketData()
{
	static char buffer[4096];
	while (_socket->bytesAvailable() > 0) {
		qint64 read = _socket->read(buffer, sizeof(buffer));
		int rc = OBEX_CustomDataFeed(_obex, reinterpret_cast<uint8_t*>(buffer), read);
		if (rc < 0) {
			qWarning() << "Could not feed data to OBEX";
		}
	}
}

void ObexConnection::handleTransferDestroyed()
{
	ObexTransfer *transfer = static_cast<ObexTransfer*>(sender());
	_pending.removeAll(transfer);
}

void ObexConnection::handleNextPending()
{
	if (!_connected) return;
	if (_busy) return;
	if (_pending.empty()) return;

	ObexTransfer *transfer = _pending.head();
	int rc = OBEX_Request(_obex, transfer->_obj);
	if (rc < 0) {
		qWarning() << "Failed to perform request";
		_socket->disconnectFromService();
		_pending.dequeue();
	} else {
		qDebug() << "Request performed";
		_busy = true;
	}
}

void ObexConnection::handleObexEvent(obex_t *handle, obex_object_t *obj, int mode, int event, int obex_cmd, int obex_rsp)
{
	ObexConnection *self = static_cast<ObexConnection*>(OBEX_GetUserData(handle));
	ObexTransfer *transfer;

	Q_UNUSED(mode);

	qDebug() << "OBEX event" << event << obex_cmd << obex_rsp;

	switch (event) {
	case OBEX_EV_PROGRESS:
		qDebug() << "Progress";
		break;
	case OBEX_EV_REQDONE:
		if (!self->_busy) {
			qWarning() << "Response was requested, but we were not expecting anything";
		}

		switch (obex_cmd) {
		case OBEX_CMD_CONNECT:
			switch (obex_rsp) {
			case OBEX_RSP_SUCCESS:
				qDebug() << "OPP OBEX connected";
				self->_connected = true;
				self->_busy = false;
				emit self->connected();
				self->handleNextPending();
				break;
			default:
				qWarning() << "OPP OBEX failed to connect:" << OBEX_ResponseToString(obex_rsp);
				self->_socket->disconnectFromService();
				break;
			}

			break;
		case OBEX_CMD_PUT:
		case OBEX_CMD_GET:
			Q_ASSERT(!self->_pending.isEmpty());
			transfer = self->_pending.dequeue();
			self->disconnect(transfer, nullptr, self, nullptr);

			if (transfer->_obj != obj) {
				qWarning() << "Got result for a request we did not make";
				self->_socket->disconnectFromService();
				return;
			}

			switch (obex_rsp) {
			case OBEX_RSP_SUCCESS:
				qDebug() << "OPP OBEX transfer success";
				emit transfer->finished();
				break;
			default:
				qWarning() << "OPP OBEX transfer failed:" << OBEX_ResponseToString(obex_rsp);
				emit transfer->error(obex_rsp);
				break;
			}

			self->_busy = false;
			self->handleNextPending();

			break;
		default:
			// Not interested
			break;
		}

		break;
	}
}

int ObexConnection::obexConnect(obex_t *handle, void *data)
{
	Q_UNUSED(handle);
	Q_UNUSED(data);
	return 1;
}

int ObexConnection::obexDisconnect(obex_t *handle, void *data)
{
	Q_UNUSED(handle);
	Q_UNUSED(data);
	return 1;
}

int ObexConnection::obexListen(obex_t *handle, void *data)
{
	Q_UNUSED(handle);
	Q_UNUSED(data);
	return -1; // Should never happen
}

int ObexConnection::obexWrite(obex_t *handle, void *data, quint8 *buf, int buflen)
{
	QBluetoothSocket *socket = static_cast<QBluetoothSocket*>(data);
	Q_UNUSED(handle);
	return socket->write(reinterpret_cast<char*>(buf), buflen);
}

int ObexConnection::obexHandleInput(obex_t *handle, void *data, int timeout)
{
	Q_UNUSED(handle);
	Q_UNUSED(data);
	Q_UNUSED(timeout);
	return 1;
}