/*

Miranda NG: the free IM client for Microsoft* Windows*

Copyright (ñ) 2012-15 Miranda NG project (http://miranda-ng.org)
all portions of this codebase are copyrighted to the people
listed in contributors.txt.

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include "commonheaders.h"

struct DBEventSortingKey
{
	DWORD dwContactId, ts, dwEventId;
};

STDMETHODIMP_(LONG) CDbxMdb::GetEventCount(MCONTACT contactID)
{
	mir_cslock lck(m_csDbAccess);
	if (contactID == NULL)
		return m_header.eventCount;

	DBCachedContact *cc = m_cache->GetCachedContact(contactID);
	return (cc == NULL) ? 0 : cc->dwDriverData;
}

STDMETHODIMP_(MEVENT) CDbxMdb::AddEvent(MCONTACT contactID, DBEVENTINFO *dbei)
{
	if (dbei == NULL || dbei->cbSize != sizeof(DBEVENTINFO)) return 0;
	if (dbei->timestamp == 0) return 0;

	DBEvent dbe;
	dbe.signature = DBEVENT_SIGNATURE;
	dbe.contactID = contactID; // store native or subcontact's id
	dbe.ofsModuleName = GetModuleNameOfs(dbei->szModule);
	dbe.timestamp = dbei->timestamp;
	dbe.flags = dbei->flags;
	dbe.wEventType = dbei->eventType;
	dbe.cbBlob = dbei->cbBlob;
	BYTE *pBlob = dbei->pBlob;

	MCONTACT contactNotifyID = contactID;
	DBCachedContact *cc = NULL, *ccSub = NULL;
	if (contactID != 0) {
		if ((cc = m_cache->GetCachedContact(contactID)) == NULL)
			return 0;

		if (cc->IsSub()) {
			ccSub = cc;
			// set default sub to the event's source
			if (!(dbei->flags & DBEF_SENT))
				db_mc_setDefault(cc->parentID, contactID, false);
			contactID = cc->parentID; // and add an event to a metahistory
			if (db_mc_isEnabled())
				contactNotifyID = contactID;
		}
	}

	if (NotifyEventHooks(hEventFilterAddedEvent, contactNotifyID, (LPARAM)dbei))
		return NULL;

	mir_ptr<BYTE> pCryptBlob;
	if (m_bEncrypted) {
		size_t len;
		BYTE *pResult = m_crypto->encodeBuffer(pBlob, dbe.cbBlob, &len);
		if (pResult != NULL) {
			pCryptBlob = pBlob = pResult;
			dbe.cbBlob = (DWORD)len;
			dbe.flags |= DBEF_ENCRYPTED;
		}
	}

	mir_cslockfull lck(m_csDbAccess);
	DWORD dwEventId = (contactID == NULL) ? ++m_header.eventCount : ++m_dwMaxEventId;

	txn_ptr txn(m_pMdbEnv);

	for (;; Remap()) {
		MDB_val key = { sizeof(int), &dwEventId }, data = { sizeof(DBEvent) + dbe.cbBlob, NULL };
		if (mdb_put(txn, m_dbEvents, &key, &data, MDB_RESERVE) != MDB_SUCCESS)
			return 0;

		BYTE *pDest = (BYTE*)data.mv_data;
		memcpy(pDest, &dbe, sizeof(DBEvent));
		memcpy(pDest + sizeof(DBEvent), pBlob, dbe.cbBlob);

		// add a sorting key
		DBEventSortingKey key2 = { contactID, dbe.timestamp, dwEventId };
		key.mv_size = sizeof(key2); key.mv_data = &key2;
		data.mv_size = 1; data.mv_data = "";
		if (mdb_put(txn, m_dbEventsSort, &key, &data, 0) != MDB_SUCCESS)
			return 0;

		if (contactID != NULL) {
			DBContact dbc = { DBCONTACT_SIGNATURE, ++cc->dwDriverData };
			MDB_val keyc = { sizeof(int), &contactID }, datac = { sizeof(DBContact), &dbc };
			mdb_put(txn, m_dbContacts, &keyc, &datac, 0);

			// insert an event into a sub's history too
			if (ccSub != NULL) {
				key2.dwContactId = ccSub->contactID;
				mdb_put(txn, m_dbEventsSort, &key, &data, 0);

				dbc.eventCount = ++ccSub->dwDriverData;
				keyc.mv_data = &ccSub->contactID;
				mdb_put(txn, m_dbContacts, &keyc, &datac, 0);
			}
		}
		else {
			DWORD keyVal = 1;
			MDB_val key = { sizeof(DWORD), &keyVal };
			data.mv_data = &m_header; data.mv_size = sizeof(m_header);
			mdb_put(txn, m_dbGlobal, &key, &data, 0);
		}

		if (txn.commit())
			break;
	}

	lck.unlock();

	// Notify only in safe mode or on really new events
	NotifyEventHooks(hEventAddedEvent, contactNotifyID, dwEventId);

	return dwEventId;
}

STDMETHODIMP_(BOOL) CDbxMdb::DeleteEvent(MCONTACT contactID, MEVENT hDbEvent)
{
	mir_cslockfull lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv);

	for (;; Remap()) {
		MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;
		if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
			return 1;

		DBEvent *dbe = (DBEvent*)data.mv_data;
		DWORD dwSavedContact = dbe->contactID;
		DBEventSortingKey key2 = { contactID, dbe->timestamp, hDbEvent };
		mdb_del(txn, m_dbEvents, &key, &data);

		// remove a sorting key
		key.mv_size = sizeof(key2); key.mv_data = &key2;
		mdb_del(txn, m_dbEventsSort, &key, &data);

		// remove a sub's history entry too
		if (contactID != dwSavedContact) {
			key2.dwContactId = dwSavedContact;
			mdb_del(txn, m_dbEventsSort, &key, &data);
		}

		if (txn.commit())
			break;
	}
	lck.unlock();

	// call notifier while outside mutex
	NotifyEventHooks(hEventDeletedEvent, contactID, hDbEvent);

	// get back in
	lck.lock();
	return 0;
}

STDMETHODIMP_(LONG) CDbxMdb::GetBlobSize(MEVENT hDbEvent)
{
	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);

	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;
	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
		return 0;

	DBEvent *dbe = (DBEvent*)data.mv_data;
	return (dbe->signature == DBEVENT_SIGNATURE) ? dbe->cbBlob : 0;
}

STDMETHODIMP_(BOOL) CDbxMdb::GetEvent(MEVENT hDbEvent, DBEVENTINFO *dbei)
{
	if (dbei == NULL || dbei->cbSize != sizeof(DBEVENTINFO)) return 1;
	if (dbei->cbBlob > 0 && dbei->pBlob == NULL) {
		dbei->cbBlob = 0;
		return 1;
	}

	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);

	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;
	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
		return 1;

	DBEvent *dbe = (DBEvent*)data.mv_data;
	if (dbe->signature != DBEVENT_SIGNATURE)
		return 1;

	dbei->szModule = GetModuleNameByOfs(dbe->ofsModuleName);
	dbei->timestamp = dbe->timestamp;
	dbei->flags = dbe->flags;
	dbei->eventType = dbe->wEventType;
	int bytesToCopy = (dbei->cbBlob < dbe->cbBlob) ? dbei->cbBlob : dbe->cbBlob;
	dbei->cbBlob = dbe->cbBlob;
	if (bytesToCopy && dbei->pBlob) {
		BYTE *pSrc = (BYTE*)data.mv_data + sizeof(DBEvent);
		if (dbe->flags & DBEF_ENCRYPTED) {
			dbei->flags &= ~DBEF_ENCRYPTED;
			size_t len;
			BYTE* pBlob = (BYTE*)m_crypto->decodeBuffer(pSrc, dbe->cbBlob, &len);
			if (pBlob == NULL)
				return 1;

			memcpy(dbei->pBlob, pBlob, bytesToCopy);
			if (bytesToCopy > (int)len)
				memset(dbei->pBlob + len, 0, bytesToCopy - len);
			mir_free(pBlob);
		}
		else memcpy(dbei->pBlob, pSrc, bytesToCopy);
	}
	return 0;
}

STDMETHODIMP_(BOOL) CDbxMdb::MarkEventRead(MCONTACT contactID, MEVENT hDbEvent)
{
	DBCachedContact *cc;
	if (contactID) {
		if ((cc = m_cache->GetCachedContact(contactID)) == NULL)
			return -1;
		if (cc->IsSub())
			if ((cc = m_cache->GetCachedContact(cc->parentID)) == NULL)
				return -1;
	}
	else cc = NULL;

	mir_cslockfull lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv);

	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;
	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
		return 0;

	DBEvent *dbe = (DBEvent*)data.mv_data;
	if (dbe->signature != DBEVENT_SIGNATURE)
		return -1;

	if (dbe->markedRead())
		return dbe->flags;

	dbe->flags |= DBEF_READ;
	mdb_put(txn, m_dbEvents, &key, &data, 0);
	txn.commit();

	lck.unlock();
	NotifyEventHooks(hEventMarkedRead, contactID, (LPARAM)hDbEvent);
	return dbe->flags;
}

STDMETHODIMP_(MCONTACT) CDbxMdb::GetEventContact(MEVENT hDbEvent)
{
	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);

	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;
	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
		return 0;

	DBEvent *dbe = (DBEvent*)data.mv_data;
	return (dbe->signature == DBEVENT_SIGNATURE) ? dbe->contactID: INVALID_CONTACT_ID;
}

STDMETHODIMP_(MEVENT) CDbxMdb::FindFirstEvent(MCONTACT contactID)
{
	DBEventSortingKey keyVal = { contactID, 0, 0 };
	MDB_val key = { sizeof(keyVal), &keyVal }, data;

	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);

	cursor_ptr cursor(txn, m_dbEventsSort);
	if (mdb_cursor_get(cursor, &key, &data, MDB_NEXT) != MDB_SUCCESS)
		return 0;

	DBEventSortingKey *pKey = (DBEventSortingKey*)key.mv_data;
	return (pKey->dwContactId == contactID) ? pKey->dwEventId : 0;		
}

STDMETHODIMP_(MEVENT) CDbxMdb::FindFirstUnreadEvent(MCONTACT contactID)
{
	mir_cslock lck(m_csDbAccess);
	return NULL;
}

STDMETHODIMP_(MEVENT) CDbxMdb::FindLastEvent(MCONTACT contactID)
{
	DBEventSortingKey keyVal = { contactID, 0, 0 };
	MDB_val key = { sizeof(keyVal), &keyVal }, data;

	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);
	
	cursor_ptr cursor(txn, m_dbEventsSort);
	if (mdb_cursor_get(cursor, &key, &data, MDB_PREV) != MDB_SUCCESS)
		return 0;

	DBEventSortingKey *pKey = (DBEventSortingKey*)key.mv_data;
	return (pKey->dwContactId == contactID) ? pKey->dwEventId : 0;
}

STDMETHODIMP_(MEVENT) CDbxMdb::FindNextEvent(MCONTACT contactID, MEVENT hDbEvent)
{
	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;

	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);
	
	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
		return 0;

	DBEvent *dbe = (DBEvent*)data.mv_data;
	DBEventSortingKey keyVal = { contactID, dbe->timestamp, hDbEvent+1 };
	key.mv_size = sizeof(keyVal); key.mv_data = &keyVal;

	cursor_ptr cursor(txn, m_dbEventsSort);
	if (mdb_cursor_get(cursor, &key, &data, MDB_SET_KEY) != MDB_SUCCESS)
		if (mdb_cursor_get(cursor, &key, &data, MDB_NEXT) != MDB_SUCCESS)
			return 0;

	DBEventSortingKey *pKey = (DBEventSortingKey*)key.mv_data;
	return (pKey->dwContactId == contactID) ? pKey->dwEventId : 0;
}

STDMETHODIMP_(MEVENT) CDbxMdb::FindPrevEvent(MCONTACT contactID, MEVENT hDbEvent)
{
	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;

	mir_cslock lck(m_csDbAccess);
	txn_ptr txn(m_pMdbEnv, true);

	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)
		return 0;

	DBEvent *dbe = (DBEvent*)data.mv_data;
	DBEventSortingKey keyVal = { contactID, dbe->timestamp, hDbEvent - 1 };
	key.mv_size = sizeof(keyVal); key.mv_data = &keyVal;

	cursor_ptr cursor(txn, m_dbEventsSort);
	if (mdb_cursor_get(cursor, &key, &data, MDB_SET_KEY) != MDB_SUCCESS)
		if (mdb_cursor_get(cursor, &key, &data, MDB_PREV) != MDB_SUCCESS)
			return 0;

	DBEventSortingKey *pKey = (DBEventSortingKey*)key.mv_data;
	return (pKey->dwContactId == contactID) ? pKey->dwEventId : 0;
}

/////////////////////////////////////////////////////////////////////////////////////////
// low-level history cleaner

int CDbxMdb::WipeContactHistory(DBContact *dbc)
{
	// drop subContact's history if any
	return 0;
}