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

#pragma once

#include <list>
#include <ctime>
#include <unordered_map>
#include "data.h"
#include "protocol.h"

class Neighbours {
	public:
		Neighbours(Protocol* proto);

		void fullCheck();
		/** Cleans the peers lists by removing the expired entries. */

		void fullUpdate();
		/** Triggers a full update of the peers lists: sends the appropriate
		 * packets to the peers (IHU, ...) when approaching expiracy, and
		 * performs a `fullCheck()`.
		 */

		void addPotentialNei(const Neighbour& nei);
		/** Adds a `Neighbour` to the list of potential neighbours. */

		void receivedFrom(u64 id);
		/** Signals that a packet was received from `id`, performs the
		 * appropriate bookkeeping actions.
		 */

		void hadIHU(u64 id);
		/** Signals that a IHU was received from `id`, performs the
		 * appropriate bookkeeping actions.
		 */

	private: //meth
		class WrongNeiType : public std::exception {};
		enum NeiType {
			NEI_UNDEF, NEI_POTENTIAL, NEI_UNIDIR, NEI_SYM
		};

		std::list<Neighbour>* listOfType(NeiType typ);
		void changeNeiType(u64 id, NeiType nType);
		void updateSendPackets(const Neighbour& nei);

		bool sendEmpty(u64 id);
		bool sendIHU(u64 id);

	private:
		Protocol* proto;
		std::list<Neighbour> potentialNei, unidirNei, symNei;
		std::unordered_map<u64, time_t> lastRecv, lastIHU;
		std::unordered_map<u64, time_t> lastPckSent, lastIHUSent;
		std::unordered_map<u64, NeiType> neiType;
		time_t lastPeerPeek;
};