/*
	PIP - Platform Independent Primitives
	Simple packet wrap aroud any PIIODevice
	Copyright (C) 2020  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 Lesser 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 Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

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

/** \class PIStreamPacker
 * \brief Simple packet wrap aroud any PIIODevice
 *
 * \section PIStreamPacker_synopsis Synopsis
 * %PIStreamPacker provides simple pack/unpack logic for any data packets.
 *
 * When you call \a send() function data splited into several
 * parts, \a packetSign() prepended to first part and \a sendRequest()
 * event raised several times.
 *
 * When your device receive some data, call \a received() function.
 * \a packetReceiveEvent() event will be raised when packet will be
 * collected.
 *
 * Use \a assignDevice() to connect device to this %PIStreamPacker.
 *
*/


PIStreamPacker::PIStreamPacker(PIIODevice * dev): PIObject() {
	crypt_frag = false;
	packet_size = -1;
	crypt_frag_size = 1024*1024;
	max_packet_size = 1400;
	packet_sign = 0xAFBE;
	assignDevice(dev);
}


void PIStreamPacker::send(const PIByteArray & data) {
	if (data.isEmpty()) return;
	PIByteArray cd;
	if (crypt_frag) {
		int fcnt = (data.size_s() - 1) / crypt_frag_size + 1, fst = 0;
		//piCout << "crypt_frag send" << fcnt << "frags";
		PIByteArray frag;
		for (int i = 0; i < fcnt; ++i) {
			if (i == fcnt - 1) frag = PIByteArray(data.data(fst), data.size_s() - fst);
			else frag = PIByteArray(data.data(fst), crypt_frag_size);
			fst += crypt_frag_size;
			cd << cryptData(frag);
		}
	} else {
		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;
	if (pcnt > 1) {
		prog_s_mutex.lock();
		prog_s.active = true;
		prog_s.bytes_all = data.size_s();
		prog_s.bytes_current = 0;
		prog_s.progress = 0.;
		prog_s_mutex.unlock();
	}
	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;
		if (pcnt > 1) {
			prog_s_mutex.lock();
			prog_s.bytes_current += part.size_s();
			prog_s.progress = (double)prog_s.bytes_current / prog_s.bytes_all;
			prog_s_mutex.unlock();
		}
	}
	if (pcnt > 1) {
		prog_s_mutex.lock();
		prog_s.active = false;
		prog_s_mutex.unlock();
	}
}


void PIStreamPacker::received(uchar * readed, int size) {
	received(PIByteArray(readed, 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;
			else {
				prog_r_mutex.lock();
				prog_r.active = true;
				prog_r.bytes_all = packet_size;
				prog_r.bytes_current = 0;
				prog_r.progress = 0.;
				prog_r_mutex.unlock();
			}
			continue;
		} else {
			int ps = piMini(stream.size_s(), packet_size - packet.size_s());
			packet.append(stream.data(), ps);
			prog_r_mutex.lock();
			prog_r.bytes_current = packet.size_s();
			prog_r.progress = (double)prog_r.bytes_current / piMaxi(1, prog_r.bytes_all);
			prog_r_mutex.unlock();
			stream.remove(0, ps);
			if (packet.size_s() == packet_size) {
				PIByteArray cd;
				if (crypt_frag) {
					//piCout << "decrypt frags ..." << packet_size;
					while (packet.size_s() >= 4) {
						//piCout << "decrypt frags take data ...";
						PIByteArray frag;
						//piCout << "decrypt frags take data done" << frag.size_s();
						packet >> frag;
						if (frag.isEmpty()) {
							//piCout << "decrypt frags corrupt, break";
							cd.clear();
							break;
						}
						cd.append(decryptData(frag));
						//piCout << "decrypt frags add" << frag.size_s();
					}
					//piCout << "decrypt frags done" << cd.size();
				} else {
					cd = decryptData(packet);
				}
				//piCout << "decrypt" << packet.size() << "->" << cd.size() << key().size();
				if (!cd.isEmpty()) {
					packetReceived(cd);
					packetReceiveEvent(cd);
				}
				packet.clear();
				packet_size = -1;
				prog_r_mutex.lock();
				prog_r.active = false;
				prog_r_mutex.unlock();
			}
		}
	}
}


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


PIStreamPacker::Progress PIStreamPacker::progressSend() const {
	PIStreamPacker::Progress ret;
	prog_s_mutex.lock();
	ret = prog_s;
	prog_s_mutex.unlock();
	return ret;
}


PIStreamPacker::Progress PIStreamPacker::progressReceive() const {
	PIStreamPacker::Progress ret;
	prog_r_mutex.lock();
	ret = prog_r;
	prog_r_mutex.unlock();
	return ret;
}




PIStreamPacker::Progress::Progress() {
	active = false;
	bytes_all = bytes_current = 0;
	progress = 0.;
}