/*
	PIP - Platform Independent Primitives
	Simple packet wrap aroud any PIIODevice
	Copyright (C) 2018  Ivan Pelipenko peri4ko@yandex.ru, Andrey Bychkov work.a.b@yandex.ru

	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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
*/

#include "pistreampacker.h"
#include "piiodevice.h"


PIStreamPacker::PIStreamPacker(PIIODevice * dev): PIObject() {
	packet_size = -1;
	max_packet_size = 1000;
	packet_sign = 0xAFBE;
	assignDevice(dev);
}


void PIStreamPacker::send(const PIByteArray &data) {
	if (data.isEmpty()) return;
	PIByteArray cd = cryptData(data);
	//piCout << "crypt" << data.size() << "->" << cd.size() << key().size();
	PIByteArray hdr, part;
	hdr << packet_sign << int(cd.size_s());
	cd.insert(0, hdr);
	int pcnt = (cd.size_s() - 1) / max_packet_size + 1, pst = 0;
	for (int i = 0; i < pcnt; ++i) {
		if (i == pcnt - 1) part = PIByteArray(cd.data(pst), cd.size_s() - pst);
		else part = PIByteArray(cd.data(pst), max_packet_size);
		//piCout << "send" << part.size();
		sendRequest(part);
		pst += max_packet_size;
	}
}


void PIStreamPacker::received(const PIByteArray & data) {
	stream.append(data);
	//piCout << "rec" << data.size();
	while (stream.size_s() >= 4) {
		if (packet_size < 0) {
			ushort sign(0);
			memcpy(&sign, stream.data(), 2);
			if (sign != packet_sign) {
				stream.pop_front();
				continue;
			}
			int sz = -1;
			memcpy(&sz, stream.data(2), 4);
			if (sz < 0) {
				stream.pop_front();
				continue;
			}
			stream.remove(0, 6);
			packet.clear();
			packet_size = sz;
			if (packet_size == 0)
				packet_size = -1;
			continue;
		} else {
			int ps = piMini(stream.size_s(), packet_size - packet.size_s());
			packet.append(stream.data(), ps);
			stream.remove(0, ps);
			if (packet.size_s() == packet_size) {
				PIByteArray cd = decryptData(packet);
				//piCout << "decrypt" << packet.size() << "->" << cd.size() << key().size();
				if (!cd.isEmpty()) packetReceiveEvent(cd);
				packet.clear();
				packet_size = -1;
			}
		}
	}
}


void PIStreamPacker::assignDevice(PIIODevice * dev) {
	if (!dev) return;
	CONNECTU(dev, threadedReadEvent, this, received);
	CONNECTU(this, sendRequest, dev, write);
}