/***************************************************************************
 * By Théophile Bastian, 2017
 * M1 Network course project at ENS Cachan, Juliusz Chroboczek.
 * License: WTFPL v2 <http://www.wtfpl.net/>
 **************************************************************************/

#include "dataStore.h"
#include <cstring>
#include <algorithm>
using namespace std;

DataStore::DataStore(Protocol* proto) : proto(proto)
{}

DataStore::~DataStore() {
}

void DataStore::update() {
	while(!timeEvents.empty()) {
		const TimeEvent& evt = timeEvents.top();
		if(evt.time > time(NULL)) // We're done for now.
			break;

		timeEvents.pop();
		switch(evt.type) {
			case EV_REPUBLISH:
				handleRepublish(evt.id);
				break;

			case EV_EXPIRES:
				handleExpire(evt.id, evt.seqno);
				break;
		}
	}
}

void DataStore::addData(Bytes pck, u32 seqno, u64 id, bool mine) {
	if(curSeqno.find(id) != curSeqno.end() && curSeqno[id] >= seqno)
		return;

	data[id] = Data(pck, mine);
	curSeqno[id] = seqno;

	if(mine) {
		timeEvents.push(TimeEvent(
					time(NULL) + csts::TIME_REPUBLISH_DATA,
					seqno, id, EV_REPUBLISH));
	}
	else {
		timeEvents.push(TimeEvent(
					time(NULL) + csts::TIMEOUT_DATA,
					seqno, id, EV_EXPIRES));
			// If it is not renewed, it will expire.
	}

	recvTime[id] = time(NULL);
	fprintf(stderr, "[INFO] Storing data %lX (%u)\n", id, seqno);

	handleFlood(id);
}

ssize_t DataStore::dataSize(u64 id) {
	if(data.find(id) == data.end())
		return -1;
	return data[id].data.size();
}

ssize_t DataStore::readData(u64 id, char* buffer, size_t size) {
	if(data.find(id) == data.end())
		return -1;
	ssize_t len = min((ssize_t)size, dataSize(id));
	data[id].data.writeToBuffer(buffer, size);
	return len;
}

void DataStore::ids(std::vector<u64>& out) {
	for(auto& dat : data)
		out.push_back(dat.first);
}

void DataStore::setFlooded(u64 id) {
	toFlood_.erase(id);
}

void DataStore::handleExpire(u64 id, u32 seqno) {
	if(seqno < curSeqno[id])
		return; // Was updated in time

	cleanData(id);
}

void DataStore::handleRepublish(u64 id) {
	if(data.find(id) == data.end() || !data[id].isMine)
		return;

	curSeqno[id] = time(NULL);
	handleFlood(id);
}

void DataStore::handleFlood(u64 id) {
	toFlood_.insert(id);
}

void DataStore::cleanData(u64 id) {
	curSeqno.erase(id);
	recvTime.erase(id);
	data.erase(id); // Deletes the Bytes as well
}