#include <cstring></cstring>

#include <chrono></chrono>

#include <thread></thread>

#include <mutex></mutex>

#include "protocol.h"

#include "server.h"

#define DebugMSG ShowDebugMSG

Server::Server():

	state(STATE_NONE),

	stateWanted(STATE_NONE),

	enqueued(false),

	error(false),

	closeWaiters(0),

	finishWaiters(0),

	address(),

	addressSize(),

	protocol(),

	prev(), next(),

	queueNext(),

	connFirst(), connLast(),

	sockId(-1),

	stateLocal()

	{ }

Server::~Server() {

	assert(state == STATE_NONE || state == STATE_FINISHED);

	closeWait();

	while(finishWaiters > 0) std::this_thread::yield();

}

bool Server::open(Protocol &protocol, void *address, size_t addressSize) {

	if (!address || !addressSize || addressSize > MAX_ADDR_SIZE)

		{ DebugMSG("bad args"); return false; }

	State s = state;

	do {

		if (s != STATE_NONE && s != STATE_FINISHED)

			{ DebugMSG("already open or in closing state"); return false; }

	} while(!state.compare_exchange_weak(s, STATE_OPENING));

	if (s == STATE_FINISHED) while(finishWaiters > 0) std::this_thread::yield();

	ReadLock lock(protocol.stateProtector);

	Protocol::State ps = protocol.state;

	if (ps < Protocol::STATE_INITIALIZING || ps >= Protocol::STATE_CLOSE_REQ)

		{ DebugMSG("protocol is closed"); state = STATE_NONE; return false; }

	memcpy(this->address, address, addressSize);

	this->addressSize = addressSize;

	this->protocol = &protocol;

	state = STATE_INITIALIZING;

	if (!enqueued.exchange(true)) protocol.srvQueue.push(*this);

	protocol.wakeup();

	return true;

}

void Server::wantState(State state, bool error) {

	ReadLock lock(stateProtector);

	State s = this->state;

	if (s <= STATE_OPENING || s >= STATE_CLOSING_CONNECTIONS || s >= state) return;

	State sw = stateWanted;

	do {

		if (sw >= state) return;

	} while(!stateWanted.compare_exchange_weak(sw, state));

	if (error) { error = false; this->error.compare_exchange_strong(error, true); }

	if (!enqueued.exchange(true)) protocol->srvQueue.push(*this);

	protocol->wakeup();

}

void Server::closeReq()

	{ wantState(STATE_CLOSE_REQ, false); }

void Server::close(bool error)

	{ wantState(STATE_CLOSING_CONNECTIONS, error); }

void Server::closeWait(unsigned long long timeoutUs, bool withReq) {

	stateProtector.lock();

	State s = state;

	if (s <= STATE_OPENING || s >= STATE_FINISHED)

		{ stateProtector.unlock(); return; }

	if (s == STATE_CLOSED) {

		finishWaiters++;

		stateProtector.unlock();

	} else {

		if (withReq && s < STATE_CLOSE_REQ) closeReq();

		closeWaiters++;

		stateProtector.unlock();

		std::mutex fakeMutex;

		{

			std::unique_lock<std::mutex> fakeLock(fakeMutex);</std::mutex>

			if (timeoutUs && s < STATE_CLOSING) {

				std::chrono::steady_clock::time_point t

					= std::chrono::steady_clock::now()

						+ std::chrono::microseconds(timeoutUs);

				while(s < STATE_CLOSED) {

					if (t <= std::chrono::steady_clock::now()) { close(true); break; }

					closeCondition.wait_until(fakeLock, t);

					s = state;

				}

			}

			if (s < STATE_CLOSING) close(true);

			while(s < STATE_CLOSED) {

				closeCondition.wait(fakeLock);

				s = state;

			}

		}

		finishWaiters++;

		closeWaiters--;

	}

	while(s != STATE_FINISHED) { std::this_thread::yield(); s = state; }

	finishWaiters--;

}

void Server::onOpeningError() { }

void Server::onOpen() { }

Connection* Server::onConnect(const void*, size_t) { return nullptr; }

void Server::onDisconnect(Connection*, bool) { }

void Server::onCloseReqested() { }

void Server::onClose(bool) { }