// ---------------------------------------------------------------------------80
//                ICQ plugin for Miranda Instant Messenger
//                ________________________________________
// 
// Copyright © 2000-2001 Richard Hughes, Roland Rabien, Tristan Van de Vreede
// Copyright © 2001-2002 Jon Keating, Richard Hughes
// Copyright © 2002-2004 Martin Öberg, Sam Kothari, Robert Rainwater
// Copyright © 2004-2010 Joe Kucera
// Copyright © 2012-2018 Miranda NG team
// 
// 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 2
// 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, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
// -----------------------------------------------------------------------------
//  DESCRIPTION:
//
//  Background thread for automatic update of user details
// -----------------------------------------------------------------------------

#include "stdafx.h"

// Retrieve users' info
void CIcqProto::icq_InitInfoUpdate(void)
{
	// Create wait objects
	hInfoQueueEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);
	if (hInfoQueueEvent) {
		// Init list
		for (int i = 0; i < LISTSIZE; i++) {
			m_infoUpdateList[i].dwUin = 0;
			m_infoUpdateList[i].hContact = NULL;
			m_infoUpdateList[i].queued = 0;
		}

		ForkThread(&CIcqProto::InfoUpdateThread, nullptr);
	}

	bInfoPendingUsers = 0;
	dwInfoActiveRequest = 0;
}

// Returns TRUE if user was queued
// Returns FALSE if the list was full
BOOL CIcqProto::icq_QueueUser(MCONTACT hContact)
{
	if (!hInfoQueueEvent)
		return FALSE;

	if (nInfoUserCount >= LISTSIZE)
		return FALSE;

	int i, nChecked = 0, nFirstFree = -1;

	mir_cslock l(infoUpdateMutex);

	// Check if in list
	for (i = 0; (i < LISTSIZE && nChecked < nInfoUserCount); i++) {
		if (m_infoUpdateList[i].hContact) {
			nChecked++;
			if (m_infoUpdateList[i].hContact == hContact)
				return TRUE;
		}
		else if (nFirstFree == -1)
			nFirstFree = i;
	}
	if (nFirstFree == -1)
		nFirstFree = i;

	// Add to list
	DWORD dwUin = getContactUin(hContact);
	if (dwUin) {
		m_infoUpdateList[nFirstFree].dwUin = dwUin;
		m_infoUpdateList[nFirstFree].hContact = hContact;
		m_infoUpdateList[nFirstFree].queued = time(nullptr);
		nInfoUserCount++;

		debugLogA("Queued user %u, place %u, count %u", dwUin, nFirstFree, nInfoUserCount);

		// Notify worker thread
		if (hInfoQueueEvent && bInfoUpdateEnabled)
			SetEvent(hInfoQueueEvent);
	}

	return TRUE;
}

void CIcqProto::icq_DequeueUser(DWORD dwUin)
{
	if (nInfoUserCount > 0) {
		int nChecked = 0;
		// Check if in list
		mir_cslock l(infoUpdateMutex);
		for (int i = 0; (i < LISTSIZE && nChecked < nInfoUserCount); i++) {
			if (m_infoUpdateList[i].dwUin) {
				nChecked++;
				// Remove from list
				if (m_infoUpdateList[i].dwUin == dwUin) {
					debugLogA("Dequeued user %u", m_infoUpdateList[i].dwUin);

					m_infoUpdateList[i].dwUin = 0;
					m_infoUpdateList[i].hContact = NULL;
					m_infoUpdateList[i].queued = 0;
					nInfoUserCount--;
					break;
				}
			}
		}
	}
}

void CIcqProto::icq_RescanInfoUpdate()
{
	bInfoPendingUsers = 0;
	/* This is here, cause we do not want to emit large number of reuqest at once,
	fill queue, and let thread deal with it */
	bInfoUpdateEnabled = 0; // freeze thread

	// Queue all outdated users
	for (MCONTACT hContact = db_find_first(m_szModuleName); hContact; hContact = db_find_next(hContact, m_szModuleName))
		if (IsMetaInfoChanged(hContact)) // Queue user
			if (!icq_QueueUser(hContact)) { // The queue is full, pause queuing contacts
				bInfoPendingUsers = 1;
				break;
			}

	bInfoUpdateEnabled = TRUE;
}

void CIcqProto::icq_EnableUserLookup(BOOL bEnable)
{
	bInfoUpdateEnabled = bEnable;

	// Notify worker thread
	if (bInfoUpdateEnabled && hInfoQueueEvent)
		SetEvent(hInfoQueueEvent);
}

void __cdecl CIcqProto::InfoUpdateThread( void* )
{
	int i;
	DWORD dwWait = WAIT_OBJECT_0;

	debugLogA("%s thread starting.", "Info-Update");
	Thread_SetName("ICQ: InfoUpdateThread");

	bInfoUpdateRunning = TRUE;

	while (bInfoUpdateRunning) {
		if (!nInfoUserCount && bInfoPendingUsers) // whole queue processed, check if more users needs updating
			icq_RescanInfoUpdate();

		if (!nInfoUserCount || !bInfoUpdateEnabled || !icqOnline()) {
			dwWait = WAIT_TIMEOUT;
			while (bInfoUpdateRunning && dwWait == WAIT_TIMEOUT) // wait for new work or until we should end
				dwWait = ICQWaitForSingleObject(hInfoQueueEvent, 10000);
		}
		if (!bInfoUpdateRunning)
			break;

		switch (dwWait) {
		case WAIT_IO_COMPLETION:
			// Possible shutdown in progress
			break;

		case WAIT_OBJECT_0:
		case WAIT_TIMEOUT:
			// Time to check for new users
			if (!bInfoUpdateEnabled)
				continue; // we can't send requests now      

			if (nInfoUserCount && icqOnline()) {
				time_t now = time(nullptr);
				BOOL bNotReady = FALSE, bTimeOuted = FALSE;

				// Check the list, take only users that were there for at least 5sec
				// wait if any user is there shorter than 5sec and not a single user is there longer than 20sec
				{
					mir_cslock l(infoUpdateMutex);
					for (i = 0; i < LISTSIZE; i++) {
						if (m_infoUpdateList[i].hContact) {
							if (m_infoUpdateList[i].queued + 20 < now) {
								bTimeOuted = TRUE;
								break;
							}
							if (m_infoUpdateList[i].queued + 5 >= now)
								bNotReady = TRUE;
						}
					}
				}

				if (!bTimeOuted && bNotReady) {
					SleepEx(1000, TRUE);
					if (!bInfoUpdateRunning) { // need to end as fast as possible
						debugLogA("%s thread ended.", "Info-Update");
						goto LBL_Exit;
					}
					continue;
				}

				// only send another request, when the previous is completed
				if (FindCookie(dwInfoActiveRequest, nullptr, nullptr)) {
					debugLogA("Info-Update: Request 0x%x still in progress.", dwInfoActiveRequest);

					SleepEx(1000, TRUE);
					if (!bInfoUpdateRunning) { // need to end as fast as possible
						debugLogA("%s thread ended.", "Info-Update");
						goto LBL_Exit;
					}
					continue;
				}

				debugLogA("Info-Update: Users %u in queue.", nInfoUserCount);

				// Either some user is waiting long enough, or all users are ready (waited at least the minimum time)
				mir_cslockfull rlck(m_ratesMutex);
				if (!m_rates) // we cannot send info request - icq is offline
					break;

				WORD wGroup = m_rates->getGroupFromSNAC(ICQ_EXTENSIONS_FAMILY, ICQ_META_CLI_REQUEST);
				while (m_rates->getNextRateLevel(wGroup) < m_rates->getLimitLevel(wGroup, RML_IDLE_30)) { // we are over rate, need to wait before sending
					int nDelay = m_rates->getDelayToLimitLevel(wGroup, RML_IDLE_50);

					rlck.unlock();

					debugLogA("Rates: InfoUpdate delayed %dms", nDelay);

					SleepEx(nDelay, TRUE); // do not keep things locked during sleep
					if (!bInfoUpdateRunning) { // need to end as fast as possible
						debugLogA("%s thread ended.", "Info-Update");
						goto LBL_Exit;
					}
					rlck.lock();
					if (!m_rates) // we lost connection when we slept, go away
						break;
				}
				if (!m_rates) // we cannot send info request - icq is offline
					break;

				rlck.unlock();

				userinfo *hContactList[LISTSIZE];
				int nListIndex = 0;
				BYTE *pRequestData = nullptr;
				size_t nRequestSize = 0;

				mir_cslock l(infoUpdateMutex);
				for (i = 0; i < LISTSIZE; i++) {
					if (m_infoUpdateList[i].hContact) {
						// check TS again, maybe it has been updated while we slept
						if (IsMetaInfoChanged(m_infoUpdateList[i].hContact)) {
							if (m_infoUpdateList[i].queued + 5 < now) {
								BYTE *pItem = nullptr;
								size_t nItemSize = 0;
								DBVARIANT dbv = { DBVT_DELETED };

								if (!getSetting(m_infoUpdateList[i].hContact, DBSETTING_METAINFO_TOKEN, &dbv)) { // retrieve user details using privacy token
									ppackTLV(&pItem, &nItemSize, 0x96, dbv.cpbVal, dbv.pbVal);
									db_free(&dbv);
								}
								// last updated time
								ppackTLVDouble(&pItem, &nItemSize, 0x64, getSettingDouble(m_infoUpdateList[i].hContact, DBSETTING_METAINFO_TIME, 0));

								ppackTLVUID(&pItem, &nItemSize, 0x32, m_infoUpdateList[i].dwUin, nullptr);
								ppackWord(&pRequestData, &nRequestSize, (WORD)nItemSize);
								ppackBuffer(&pRequestData, &nRequestSize, nItemSize, pItem);
								// take a reference
								SAFE_FREE((void**)&pItem);
								hContactList[nListIndex++] = &m_infoUpdateList[i];
							}
						}
						else {
							debugLogA("Dequeued absolete user %u", m_infoUpdateList[i].dwUin);

							// Dequeue user and find another one
							m_infoUpdateList[i].dwUin = 0;
							m_infoUpdateList[i].hContact = NULL;
							nInfoUserCount--;
							// continue for loop
						}
					}
				}

				debugLogA("Request info for %u user(s).", nListIndex);

				if (!nListIndex) // no users to request info for
					break;

				if (!(dwInfoActiveRequest = sendUserInfoMultiRequest(pRequestData, nRequestSize, nListIndex))) { // sending data packet failed
					SAFE_FREE((void**)&pRequestData);
					break;
				}
				SAFE_FREE((void**)&pRequestData);

				for (i = 0; i < nListIndex; i++) { // Dequeue users and go back to sleep
					hContactList[i]->dwUin = 0;
					hContactList[i]->hContact = NULL;
					hContactList[i]->queued = 0;
					nInfoUserCount--;
				}
			}
			break;

		default:
			// Something strange happened. Exit
			bInfoUpdateRunning = FALSE;
			break;
		}
	}

	debugLogA("%s thread ended.", "Info-Update");

LBL_Exit:
	CloseHandle(hInfoQueueEvent);
}

// Clean up before exit
void CIcqProto::icq_InfoUpdateCleanup(void)
{
	debugLogA("%s must die.", "Info-Update");
	bInfoUpdateRunning = FALSE;
	if (hInfoQueueEvent)
		SetEvent(hInfoQueueEvent); // break queue loop
}