/*
Copyright © 2016-17 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, see <http://www.gnu.org/licenses/>.
*/

#include "stdafx.h"

#pragma pack(4)

struct CDiscordCommand
{
	const wchar_t *szCommandId;
	GatewayHandlerFunc pFunc;
}
static handlers[] = // these structures must me sorted alphabetically
{
	{ L"CHANNEL_CREATE", &CDiscordProto::OnCommandChannelCreated },
	{ L"CHANNEL_DELETE", &CDiscordProto::OnCommandChannelDeleted },

	{ L"GUILD_SYNC", &CDiscordProto::OnCommandGuildSync },

	{ L"MESSAGE_ACK",    &CDiscordProto::OnCommandMessageAck },
	{ L"MESSAGE_CREATE", &CDiscordProto::OnCommandMessage },
	{ L"MESSAGE_UPDATE", &CDiscordProto::OnCommandMessage },

	{ L"PRESENCE_UPDATE", &CDiscordProto::OnCommandPresence },

	{ L"READY", &CDiscordProto::OnCommandReady },

	{ L"RELATIONSHIP_ADD", &CDiscordProto::OnCommandFriendAdded },
	{ L"RELATIONSHIP_REMOVE", &CDiscordProto::OnCommandFriendRemoved },

	{ L"TYPING_START", &CDiscordProto::OnCommandTyping },

	{ L"USER_SETTINGS_UPDATE", &CDiscordProto::OnCommandUserSettingsUpdate },
	{ L"USER_UPDATE", &CDiscordProto::OnCommandUserUpdate },
};

static int __cdecl pSearchFunc(const void *p1, const void *p2)
{
	return wcscmp(((CDiscordCommand*)p1)->szCommandId, ((CDiscordCommand*)p2)->szCommandId);
}

GatewayHandlerFunc CDiscordProto::GetHandler(const wchar_t *pwszCommand)
{
	CDiscordCommand tmp = { pwszCommand, NULL };
	CDiscordCommand *p = (CDiscordCommand*)bsearch(&tmp, handlers, _countof(handlers), sizeof(handlers[0]), pSearchFunc);
	return (p != NULL) ? p->pFunc : NULL;
}

//////////////////////////////////////////////////////////////////////////////////////
// channel operations

void CDiscordProto::OnCommandChannelCreated(const JSONNode &pRoot)
{
	const JSONNode &members = pRoot["recipients"];
	for (auto it = members.begin(); it != members.end(); ++it) {
		CDiscordUser *pUser = PrepareUser(*it);
		pUser->lastMessageId = _wtoi64(pRoot["last_message_id"].as_mstring());
		pUser->channelId = _wtoi64(pRoot["id"].as_mstring());
		setId(pUser->hContact, DB_KEY_CHANNELID, pUser->channelId);
	}
}

void CDiscordProto::OnCommandChannelDeleted(const JSONNode &pRoot)
{
	CDiscordUser *pUser = FindUserByChannel(_wtoi64(pRoot["id"].as_mstring()));
	if (pUser != NULL) {
		pUser->channelId = pUser->lastMessageId = 0;
		delSetting(pUser->hContact, DB_KEY_CHANNELID);
	}
}

//////////////////////////////////////////////////////////////////////////////////////
// reading a new message

void CDiscordProto::OnCommandFriendAdded(const JSONNode &pRoot)
{
	CDiscordUser *pUser = PrepareUser(pRoot["user"]);
	pUser->bIsPrivate = true;
	ProcessType(pUser, pRoot);
}

void CDiscordProto::OnCommandFriendRemoved(const JSONNode &pRoot)
{
	SnowFlake id = _wtoi64(pRoot["id"].as_mstring());
	CDiscordUser *pUser = FindUser(id);
	if (pUser != NULL) {
		if (pUser->hContact) {
			if (pUser->bIsPrivate)
				db_delete_contact(pUser->hContact);
		}
		arUsers.remove(pUser);
	}
}

//////////////////////////////////////////////////////////////////////////////////////
// reading a new message

void CDiscordProto::OnCommandGuildSync(const JSONNode &pRoot)
{
	struct Presence
	{
		Presence(SnowFlake _id, int status) :
			userid(_id),
			iStatus(status)
		{}

		SnowFlake userid;
		int iStatus;

		static int compare(const Presence *p1, const Presence *p2)
		{	return p1->userid - p2->userid;
		}
	};

	OBJLIST<Presence> arPresences(1, &Presence::compare);
	const JSONNode &pStatuses = pRoot["presences"];
	for (auto it = pStatuses.begin(); it != pStatuses.end(); ++it) {
		const JSONNode &s = *it;

		int iStatus = StrToStatus(s["status"].as_mstring());
		if (iStatus)
			arPresences.insert(new Presence(_wtoi64(s["user"]["id"].as_mstring()), iStatus));
	}

	SnowFlake guildId = _wtoi64(pRoot["id"].as_mstring());

	const JSONNode &pMembers = pRoot["members"];
	for (auto it = pMembers.begin(); it != pMembers.end(); ++it) {
		const JSONNode &m = *it;

		for (int i = 0; i < arUsers.getCount(); i++) {
			CDiscordUser &pUser = arUsers[i];
			if (pUser.guildId != guildId)
				continue;

			GCDEST gcd = { m_szModuleName, pUser.wszUsername, GC_EVENT_JOIN };
			GCEVENT gce = { &gcd };

			CMStringW wszUsername = m["user"]["username"].as_mstring() + L"#" + m["user"]["discriminator"].as_mstring();
			CMStringW wszUserId = m["user"]["id"].as_mstring();
			SnowFlake userid = _wtoi64(wszUserId);
			gce.bIsMe = (userid == m_ownId);
			gce.ptszUID = wszUserId;
			gce.ptszNick = wszUsername;
			Chat_Event(&gce);

			int flags = GC_SSE_ONLYLISTED;
			Presence *p = arPresences.find((Presence*)&userid);
			if (p && (p->iStatus == ID_STATUS_ONLINE || p->iStatus == ID_STATUS_NA || p->iStatus == ID_STATUS_DND))
				flags += GC_SSE_ONLINE;
			else
				flags += GC_SSE_OFFLINE;
			Chat_SetStatusEx(m_szModuleName, pUser.wszUsername, flags, wszUserId);
		}
	}
}

//////////////////////////////////////////////////////////////////////////////////////
// reading a new message

void CDiscordProto::OnCommandMessage(const JSONNode &pRoot)
{
	PROTORECVEVENT recv = {};
	CMStringW wszMessageId = pRoot["id"].as_mstring();
	SnowFlake messageId = _wtoi64(wszMessageId);
	SnowFlake nonce = _wtoi64(pRoot["nonce"].as_mstring());

	SnowFlake *p = arOwnMessages.find(&nonce);
	if (p != NULL) { // own message? skip it
		debugLogA("skipping own message with nonce=%lld, id=%lld", nonce, messageId);
		return;
	}

	// try to find a sender by his channel
	CMStringW wszChannelId = pRoot["channel_id"].as_mstring();
	SnowFlake channelId = _wtoi64(wszChannelId);
	CDiscordUser *pUser = FindUserByChannel(channelId);
	if (pUser == NULL) {
		debugLogA("skipping message with unknown channel id=%lld", channelId);
		return;
	}

	// if a message has myself as an author, add some flags
	CMStringW wszUserId = pRoot["author"]["id"].as_mstring();
	if (_wtoi64(wszUserId) == m_ownId)
		recv.flags = PREF_CREATEREAD | PREF_SENT;

	CMStringW wszText = pRoot["content"].as_mstring();

	const JSONNode &edited = pRoot["edited_timestamp"];
	if (!edited.isnull())
		wszText.AppendFormat(L" (%s %s)", TranslateT("edited at"), edited.as_mstring().c_str());

	if (pUser->bIsPrivate) {
		debugLogA("store a message from private user %lld, channel id %lld", pUser->id, pUser->channelId);
		ptrA buf(mir_utf8encodeW(wszText));
		recv.timestamp = (DWORD)StringToDate(pRoot["timestamp"].as_mstring());
		recv.szMessage = buf;
		recv.lParam = (LPARAM)wszMessageId.c_str();
		ProtoChainRecvMsg(pUser->hContact, &recv);

		SnowFlake lastId = getId(pUser->hContact, DB_KEY_LASTMSGID); // as stored in a database
		if (lastId < messageId)
			setId(pUser->hContact, DB_KEY_LASTMSGID, messageId);
	}
	else {
		debugLogA("store a message into the group channel id %lld", channelId);
		CMStringW wszUserName = pRoot["author"]["id"].as_mstring();
		CMStringW wszUserNick = pRoot["author"]["username"].as_mstring() + L"#" + pRoot["author"]["discriminator"].as_mstring();

		GCDEST gcd = { m_szModuleName, wszChannelId, GC_EVENT_MESSAGE };
		GCEVENT gce = { &gcd };
		gce.dwFlags = GCEF_ADDTOLOG;
		gce.ptszUID = wszUserId;
		gce.ptszNick = wszUserNick;
		gce.ptszText = wszText;
		gce.time = (DWORD)StringToDate(pRoot["timestamp"].as_mstring());
		gce.bIsMe = _wtoi64(wszUserId) == m_ownId;
		Chat_Event(&gce);
	}
}

//////////////////////////////////////////////////////////////////////////////////////
// someone changed its status

void CDiscordProto::OnCommandMessageAck(const JSONNode &pRoot)
{
	CDiscordUser *pUser = FindUserByChannel(pRoot["channel_id"]);
	if (pUser != NULL)
		pUser->lastMessageId = _wtoi64(pRoot["message_id"].as_mstring());
}

//////////////////////////////////////////////////////////////////////////////////////
// someone changed its status

void CDiscordProto::OnCommandPresence(const JSONNode &pRoot)
{
	CDiscordUser *pUser = FindUser(_wtoi64(pRoot["user"]["id"].as_mstring()));
	if (pUser == NULL)
		return;

	int iStatus = StrToStatus(pRoot["status"].as_mstring());
	if (iStatus != 0)
		setWord(pUser->hContact, "Status", iStatus);

	CMStringW wszGame = pRoot["game"]["name"].as_mstring();
	if (!wszGame.IsEmpty())
		setWString(pUser->hContact, "XStatusMsg", wszGame);
	else
		delSetting(pUser->hContact, "XStatusMsg");		
}

//////////////////////////////////////////////////////////////////////////////////////
// gateway session start

void CALLBACK CDiscordProto::HeartbeatTimerProc(HWND, UINT, UINT_PTR id, DWORD)
{
	((CDiscordProto*)id)->GatewaySendHeartbeat();
}

static void __stdcall sttStartTimer(void *param)
{
	CDiscordProto *ppro = (CDiscordProto*)param;
	SetTimer(g_hwndHeartbeat, (UINT_PTR)param, ppro->getHeartbeatInterval(), &CDiscordProto::HeartbeatTimerProc);
}

static SnowFlake sttGetLastRead(const JSONNode &reads, const wchar_t *wszChannelId)
{
	for (auto it = reads.begin(); it != reads.end(); ++it) {
		const JSONNode &p = *it;

		if (p["id"].as_mstring() == wszChannelId)
			return _wtoi64(p["last_message_id"].as_mstring());
	}
	return 0;
}

void CDiscordProto::OnCommandReady(const JSONNode &pRoot)
{
	GatewaySendHeartbeat();
	CallFunctionAsync(sttStartTimer, this);

	m_szGatewaySessionId = pRoot["session_id"].as_mstring();

	const JSONNode &readState = pRoot["read_state"];

	const JSONNode &guilds = pRoot["guilds"];
	for (auto it = guilds.begin(); it != guilds.end(); ++it) {
		const JSONNode &p = *it;

		SnowFlake guildId = _wtoi64(p["id"].as_mstring());
		GatewaySendGuildInfo(guildId);
		CMStringW wszGuildName = p["name"].as_mstring();

		GCSessionInfoBase *si = Chat_NewSession(GCW_SERVER, m_szModuleName, wszGuildName, wszGuildName);
		Chat_Control(m_szModuleName, wszGuildName, WINDOW_HIDDEN);
		Chat_Control(m_szModuleName, wszGuildName, SESSION_ONLINE);

		const JSONNode &channels = p["channels"];
		for (auto itc = channels.begin(); itc != channels.end(); ++itc) {
			const JSONNode &pch = *itc;
			if (pch["type"].as_int() != 0)
				continue;

			CMStringW wszChannelName = pch["name"].as_mstring();
			CMStringW wszChannelId = pch["id"].as_mstring();
			SnowFlake channelId = _wtoi64(wszChannelId);

			si = Chat_NewSession(GCW_CHATROOM, m_szModuleName, wszChannelId, wszGuildName + L"#" + wszChannelName);
			Chat_AddGroup(m_szModuleName, wszChannelId, TranslateT("User"));
			Chat_Control(m_szModuleName, wszChannelId, WINDOW_HIDDEN);
			Chat_Control(m_szModuleName, wszChannelId, SESSION_ONLINE);

			CDiscordUser *pUser = FindUserByChannel(channelId);
			if (pUser == NULL) {
				// missing channel - create it
				pUser = new CDiscordUser(channelId);
				pUser->bIsPrivate = false;
				pUser->hContact = si->hContact;
				pUser->channelId = channelId;
				arUsers.insert(pUser);
			}
			pUser->wszUsername = wszChannelId;
			pUser->guildId = guildId;
			pUser->lastMessageId = _wtoi64(pch["last_message_id"].as_mstring());
			pUser->lastReadId = sttGetLastRead(readState, wszChannelId);

			setId(pUser->hContact, DB_KEY_CHANNELID, channelId);
		}
	}

	const JSONNode &relations = pRoot["relationships"];
	for (auto it = relations.begin(); it != relations.end(); ++it) {
		const JSONNode &p = *it;

		CDiscordUser *pUser = PrepareUser(p["user"]);
		ProcessType(pUser, p);
	}

	const JSONNode &channels = pRoot["private_channels"];
	for (auto it = channels.begin(); it != channels.end(); ++it) {
		const JSONNode &p = *it;

		CDiscordUser *pUser = NULL;
		const JSONNode &recipients = p["recipients"];
		for (auto it2 = recipients.begin(); it2 != recipients.end(); ++it2)
			pUser = PrepareUser(*it2);

		if (pUser == NULL)
			continue;
		
		CMStringW wszChannelId = p["id"].as_mstring();
		pUser->channelId = _wtoi64(wszChannelId);
		pUser->lastMessageId = _wtoi64(p["last_message_id"].as_mstring());
		pUser->lastReadId = sttGetLastRead(readState, wszChannelId);
		pUser->bIsPrivate = true;

		setId(pUser->hContact, DB_KEY_CHANNELID, pUser->channelId);

		SnowFlake oldMsgId = getId(pUser->hContact, DB_KEY_LASTMSGID);
		if (pUser->lastMessageId > oldMsgId)
			RetrieveHistory(pUser->hContact, MSG_AFTER, oldMsgId, 99);
	}
}

//////////////////////////////////////////////////////////////////////////////////////
// UTN support

void CDiscordProto::OnCommandTyping(const JSONNode &pRoot)
{
	SnowFlake userId = _wtoi64(pRoot["user_id"].as_mstring());
	SnowFlake channelId = _wtoi64(pRoot["channel_id"].as_mstring());
	debugLogA("user typing notification: userid=%lld, channelid=%lld", userId, channelId);

	CDiscordUser *pUser = FindUser(userId);
	if (pUser == NULL) {
		debugLogA("user with id=%lld is not found", userId);
		return;
	}

	if (pUser->channelId == channelId) {
		debugLogA("user is typing in his private channel");
		CallService(MS_PROTO_CONTACTISTYPING, pUser->hContact, 20);
	}
	else {
		debugLogA("user is typing in a group channel, skipped");
	}
}

//////////////////////////////////////////////////////////////////////////////////////
// UTN support

void CDiscordProto::OnCommandUserUpdate(const JSONNode &pRoot)
{
	SnowFlake id = _wtoi64(pRoot["id"].as_mstring());

	MCONTACT hContact;
	if (id != m_ownId) {
		CDiscordUser *pUser = FindUser(id);
		if (pUser == NULL)
			return;

		hContact = pUser->hContact;
	}
	else hContact = 0;

	// force rereading avatar
	ptrW wszOldHash(getWStringA(hContact, DB_KEY_AVHASH));
	CMStringW wszNewHash(pRoot["avatar"].as_mstring());
	if (mir_wstrcmp(wszOldHash, wszNewHash)) {
		setWString(hContact, DB_KEY_AVHASH, wszNewHash);
		RetrieveAvatar(hContact);
	}
}

void CDiscordProto::OnCommandUserSettingsUpdate(const JSONNode &pRoot)
{
	int iStatus = StrToStatus(pRoot["status"].as_mstring());
	if (iStatus != 0) {
		int iOldStatus = m_iStatus; m_iStatus = iStatus;
		ProtoBroadcastAck(NULL, ACKTYPE_STATUS, ACKRESULT_SUCCESS, (HANDLE)iOldStatus, m_iStatus);
	}
}