/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.

For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "api/api_chat_participants.h"

#include "apiwrap.h"
#include "boxes/add_contact_box.h" // ShowAddParticipantsError
#include "boxes/peers/add_participants_box.h" // ChatInviteForbidden
#include "data/data_changes.h"
#include "data/data_channel.h"
#include "data/data_channel_admins.h"
#include "data/data_chat.h"
#include "data/data_histories.h"
#include "data/data_session.h"
#include "data/data_user.h"
#include "history/history.h"
#include "main/main_session.h"
#include "mtproto/mtproto_config.h"

namespace Api {
namespace {

using Members = ChatParticipants::Members;

constexpr auto kSmallDelayMs = crl::time(5);

// 1 second wait before reload members in channel after adding.
constexpr auto kReloadChannelMembersTimeout = 1000;

// Max users in one super group invite request.
constexpr auto kMaxUsersPerInvite = 100;

// How many messages from chat history server should forward to user,
// that was added to this chat.
constexpr auto kForwardMessagesOnAdd = 100;

std::vector<ChatParticipant> ParseList(
		const ChatParticipants::TLMembers &data,
		not_null<PeerData*> peer) {
	return ranges::views::all(
		data.vparticipants().v
	) | ranges::views::transform([&](const MTPChannelParticipant &p) {
		return ChatParticipant(p, peer);
	}) | ranges::to_vector;
}

void ApplyMegagroupAdmins(not_null<ChannelData*> channel, Members list) {
	Expects(channel->isMegagroup());

	const auto i = ranges::find_if(list, &Api::ChatParticipant::isCreator);
	if (i != list.end()) {
		i->tryApplyCreatorTo(channel);
	} else {
		channel->mgInfo->creator = nullptr;
		channel->mgInfo->creatorRank = QString();
	}

	auto adding = base::flat_map<UserId, QString>();
	for (const auto &p : list) {
		if (p.isUser()) {
			adding.emplace(p.userId(), p.rank());
		}
	}
	if (channel->mgInfo->creator) {
		adding.emplace(
			peerToUser(channel->mgInfo->creator->id),
			channel->mgInfo->creatorRank);
	}
	auto removing = channel->mgInfo->admins;
	if (removing.empty() && adding.empty()) {
		// Add some admin-placeholder so we don't DDOS
		// server with admins list requests.
		LOG(("API Error: Got empty admins list from server."));
		adding.emplace(0, QString());
	}

	Data::ChannelAdminChanges changes(channel);
	for (const auto &[addingId, rank] : adding) {
		if (!removing.remove(addingId)) {
			changes.add(addingId, rank);
		}
	}
	for (const auto &[removingId, rank] : removing) {
		changes.remove(removingId);
	}
}

void RefreshChannelAdmins(
		not_null<ChannelData*> channel,
		Members participants) {
	Data::ChannelAdminChanges changes(channel);
	for (const auto &p : participants) {
		if (p.isUser()) {
			if (p.isCreatorOrAdmin()) {
				p.tryApplyCreatorTo(channel);
				changes.add(p.userId(), p.rank());
			} else {
				changes.remove(p.userId());
			}
		}
	}
}

void ApplyLastList(
		not_null<ChannelData*> channel,
		int availableCount,
		Members list) {
	channel->mgInfo->lastAdmins.clear();
	channel->mgInfo->lastRestricted.clear();
	channel->mgInfo->lastParticipants.clear();
	channel->mgInfo->lastParticipantsStatus =
		MegagroupInfo::LastParticipantsUpToDate
			| MegagroupInfo::LastParticipantsOnceReceived;

	auto botStatus = channel->mgInfo->botStatus;
	for (const auto &p : list) {
		const auto participant = channel->owner().peer(p.id());
		const auto user = participant->asUser();
		const auto adminRights = p.rights();
		const auto restrictedRights = p.restrictions();
		if (p.isCreator()) {
			Assert(user != nullptr);
			p.tryApplyCreatorTo(channel);
			if (!channel->mgInfo->admins.empty()) {
				Data::ChannelAdminChanges(channel).add(p.userId(), p.rank());
			}
		}
		if (user
			&& !base::contains(channel->mgInfo->lastParticipants, user)) {
			channel->mgInfo->lastParticipants.push_back(user);
			if (adminRights.flags) {
				channel->mgInfo->lastAdmins.emplace(
					user,
					MegagroupInfo::Admin{ adminRights, p.canBeEdited() });
			} else if (restrictedRights.flags) {
				channel->mgInfo->lastRestricted.emplace(
					user,
					MegagroupInfo::Restricted{ restrictedRights });
			}
			if (user->isBot()) {
				channel->mgInfo->bots.insert(user);
				if ((channel->mgInfo->botStatus != 0)
					&& (channel->mgInfo->botStatus < 2)) {
					channel->mgInfo->botStatus = 2;
				}
			}
		}
	}
	//
	// getParticipants(Recent) sometimes can't return all members,
	// only some last subset, size of this subset is availableCount.
	//
	// So both list size and availableCount have nothing to do with
	// the full supergroup members count.
	//
	//if (list.isEmpty()) {
	//	channel->setMembersCount(channel->mgInfo->lastParticipants.size());
	//} else {
	//	channel->setMembersCount(availableCount);
	//}
	channel->session().changes().peerUpdated(
		channel,
		(Data::PeerUpdate::Flag::Members | Data::PeerUpdate::Flag::Admins));

	channel->mgInfo->botStatus = botStatus;
	channel->session().changes().peerUpdated(
		channel,
		Data::PeerUpdate::Flag::FullInfo);
}

void ApplyBotsList(
		not_null<ChannelData*> channel,
		int availableCount,
		Members list) {
	const auto history = channel->owner().historyLoaded(channel);
	channel->mgInfo->bots.clear();
	channel->mgInfo->botStatus = -1;

	auto needBotsInfos = false;
	auto botStatus = channel->mgInfo->botStatus;
	auto keyboardBotFound = !history || !history->lastKeyboardFrom;
	for (const auto &p : list) {
		const auto participant = channel->owner().peer(p.id());
		const auto user = participant->asUser();
		if (user && user->isBot()) {
			channel->mgInfo->bots.insert(user);
			botStatus = 2;// (botStatus > 0/* || !i.key()->botInfo->readsAllHistory*/) ? 2 : 1;
			if (!user->botInfo->inited) {
				needBotsInfos = true;
			}
		}
		if (!keyboardBotFound
			&& participant->id == history->lastKeyboardFrom) {
			keyboardBotFound = true;
		}
	}
	if (needBotsInfos) {
		channel->session().api().requestFullPeer(channel);
	}
	if (!keyboardBotFound) {
		history->clearLastKeyboard();
	}

	channel->mgInfo->botStatus = botStatus;
	channel->session().changes().peerUpdated(
		channel,
		Data::PeerUpdate::Flag::FullInfo);
}

[[nodiscard]] ChatParticipants::Channels ParseSimilar(
		not_null<ChannelData*> channel,
		const MTPmessages_Chats &chats) {
	auto result = ChatParticipants::Channels();
	std::vector<not_null<ChannelData*>>();
	chats.match([&](const auto &data) {
		const auto &list = data.vchats().v;
		result.list.reserve(list.size());
		for (const auto &chat : list) {
			const auto peer = channel->owner().processChat(chat);
			if (const auto channel = peer->asChannel()) {
				result.list.push_back(channel);
			}
		}
		if constexpr (MTPDmessages_chatsSlice::Is<decltype(data)>()) {
			if (channel->session().premiumPossible()) {
				result.more = data.vcount().v - data.vchats().v.size();
			}
		}
	});
	return result;
}

} // namespace

ChatParticipant::ChatParticipant(
		const MTPChannelParticipant &p,
		not_null<PeerData*> peer) {
	_peer = p.match([](const MTPDchannelParticipantBanned &data) {
		return peerFromMTP(data.vpeer());
	}, [](const MTPDchannelParticipantLeft &data) {
		return peerFromMTP(data.vpeer());
	}, [](const auto &data) {
		return peerFromUser(data.vuser_id());
	});

	p.match([&](const MTPDchannelParticipantCreator &data) {
		_canBeEdited = (peer->session().userPeerId() == _peer);
		_type = Type::Creator;
		_rights = ChatAdminRightsInfo(data.vadmin_rights());
		_rank = qs(data.vrank().value_or_empty());
	}, [&](const MTPDchannelParticipantAdmin &data) {
		_canBeEdited = data.is_can_edit();
		_type = Type::Admin;
		_rank = qs(data.vrank().value_or_empty());
		_rights = ChatAdminRightsInfo(data.vadmin_rights());
		_by = peerToUser(peerFromUser(data.vpromoted_by()));
	}, [&](const MTPDchannelParticipantSelf &data) {
		_type = Type::Member;
		_by = peerToUser(peerFromUser(data.vinviter_id()));
	}, [&](const MTPDchannelParticipant &data) {
		_type = Type::Member;
	}, [&](const MTPDchannelParticipantBanned &data) {
		_restrictions = ChatRestrictionsInfo(data.vbanned_rights());
		_by = peerToUser(peerFromUser(data.vkicked_by()));

		_type = (_restrictions.flags & ChatRestriction::ViewMessages)
			? Type::Banned
			: Type::Restricted;
	}, [&](const MTPDchannelParticipantLeft &data) {
		_type = Type::Left;
	});
}

ChatParticipant::ChatParticipant(
	Type type,
	PeerId peerId,
	UserId by,
	ChatRestrictionsInfo restrictions,
	ChatAdminRightsInfo rights,
	bool canBeEdited,
	QString rank)
: _type(type)
, _peer(peerId)
, _by(by)
, _canBeEdited(canBeEdited)
, _rank(rank)
, _restrictions(std::move(restrictions))
, _rights(std::move(rights)) {
}

void ChatParticipant::tryApplyCreatorTo(
		not_null<ChannelData*> channel) const {
	if (isCreator() && isUser()) {
		if (const auto info = channel->mgInfo.get()) {
			info->creator = channel->owner().userLoaded(userId());
			info->creatorRank = rank();
		}
	}
}

bool ChatParticipant::isUser() const {
	return peerIsUser(_peer);
}

bool ChatParticipant::isCreator() const {
	return _type == Type::Creator;
}

bool ChatParticipant::isCreatorOrAdmin() const {
	return _type == Type::Creator || _type == Type::Admin;
}

bool ChatParticipant::isKicked() const {
	return _type == Type::Banned;
}

bool ChatParticipant::canBeEdited() const {
	return _canBeEdited;
}

UserId ChatParticipant::by() const {
	return _by;
}

PeerId ChatParticipant::id() const {
	return _peer;
}

UserId ChatParticipant::userId() const {
	return peerToUser(_peer);
}

ChatRestrictionsInfo ChatParticipant::restrictions() const {
	return _restrictions;
}

ChatAdminRightsInfo ChatParticipant::rights() const {
	return _rights;
}

ChatParticipant::Type ChatParticipant::type() const {
	return _type;
}

QString ChatParticipant::rank() const {
	return _rank;
}

ChatParticipants::ChatParticipants(not_null<ApiWrap*> api)
: _api(&api->instance()) {
}

void ChatParticipants::requestForAdd(
		not_null<ChannelData*> channel,
		Fn<void(const TLMembers&)> callback) {
	Expects(callback != nullptr);
	_forAdd.callback = std::move(callback);
	if (_forAdd.channel == channel) {
		return;
	}
	_api.request(base::take(_forAdd.requestId)).cancel();

	const auto offset = 0;
	const auto participantsHash = uint64(0);

	_forAdd.channel = channel;
	_forAdd.requestId = _api.request(MTPchannels_GetParticipants(
		channel->inputChannel,
		MTP_channelParticipantsRecent(),
		MTP_int(offset),
		MTP_int(channel->session().serverConfig().chatSizeMax),
		MTP_long(participantsHash)
	)).done([=](const MTPchannels_ChannelParticipants &result) {
		result.match([&](const MTPDchannels_channelParticipants &data) {
			base::take(_forAdd).callback(data);
		}, [&](const MTPDchannels_channelParticipantsNotModified &) {
			base::take(_forAdd);
			LOG(("API Error: "
				"channels.channelParticipantsNotModified received!"));
		});
	}).fail([=] {
		base::take(_forAdd);
	}).send();
}

void ChatParticipants::requestLast(not_null<ChannelData*> channel) {
	if (!channel->isMegagroup()
		|| !channel->canViewMembers()
		|| _participantsRequests.contains(channel)) {
		return;
	}

	const auto offset = 0;
	const auto participantsHash = uint64(0);
	const auto requestId = _api.request(MTPchannels_GetParticipants(
		channel->inputChannel,
		MTP_channelParticipantsRecent(),
		MTP_int(offset),
		MTP_int(channel->session().serverConfig().chatSizeMax),
		MTP_long(participantsHash)
	)).done([=](const MTPchannels_ChannelParticipants &result) {
		_participantsRequests.remove(channel);

		result.match([&](const MTPDchannels_channelParticipants &data) {
			const auto &[availableCount, list] = Parse(channel, data);
			ApplyLastList(channel, availableCount, list);
		}, [](const MTPDchannels_channelParticipantsNotModified &) {
			LOG(("API Error: "
				"channels.channelParticipantsNotModified received!"));
		});
	}).fail([this, channel] {
		_participantsRequests.remove(channel);
	}).send();

	_participantsRequests[channel] = requestId;
}

void ChatParticipants::requestBots(not_null<ChannelData*> channel) {
	if (!channel->isMegagroup() || _botsRequests.contains(channel)) {
		return;
	}

	const auto offset = 0;
	const auto participantsHash = uint64(0);
	const auto requestId = _api.request(MTPchannels_GetParticipants(
		channel->inputChannel,
		MTP_channelParticipantsBots(),
		MTP_int(offset),
		MTP_int(channel->session().serverConfig().chatSizeMax),
		MTP_long(participantsHash)
	)).done([=](const MTPchannels_ChannelParticipants &result) {
		_botsRequests.remove(channel);
		result.match([&](const MTPDchannels_channelParticipants &data) {
			const auto &[availableCount, list] = Parse(channel, data);
			ApplyBotsList(channel, availableCount, list);
		}, [](const MTPDchannels_channelParticipantsNotModified &) {
			LOG(("API Error: "
				"channels.channelParticipantsNotModified received!"));
		});
	}).fail([=] {
		_botsRequests.remove(channel);
	}).send();

	_botsRequests[channel] = requestId;
}

void ChatParticipants::requestAdmins(not_null<ChannelData*> channel) {
	if (!channel->isMegagroup() || _adminsRequests.contains(channel)) {
		return;
	}

	const auto offset = 0;
	const auto participantsHash = uint64(0);
	const auto requestId = _api.request(MTPchannels_GetParticipants(
		channel->inputChannel,
		MTP_channelParticipantsAdmins(),
		MTP_int(offset),
		MTP_int(channel->session().serverConfig().chatSizeMax),
		MTP_long(participantsHash)
	)).done([=](const MTPchannels_ChannelParticipants &result) {
		channel->mgInfo->adminsLoaded = true;
		_adminsRequests.remove(channel);
		result.match([&](const MTPDchannels_channelParticipants &data) {
			channel->owner().processUsers(data.vusers());
			ApplyMegagroupAdmins(channel, ParseList(data, channel));
		}, [](const MTPDchannels_channelParticipantsNotModified &) {
			LOG(("API Error: "
				"channels.channelParticipantsNotModified received!"));
		});
	}).fail([=] {
		channel->mgInfo->adminsLoaded = true;
		_adminsRequests.remove(channel);
	}).send();

	_adminsRequests[channel] = requestId;
}

void ChatParticipants::requestCountDelayed(
		not_null<ChannelData*> channel) {
	_participantsCountRequestTimer.call(
		kReloadChannelMembersTimeout,
		[=] { channel->updateFullForced(); });
}

void ChatParticipants::add(
		not_null<PeerData*> peer,
		const std::vector<not_null<UserData*>> &users,
		std::shared_ptr<Ui::Show> show,
		bool passGroupHistory,
		Fn<void(bool)> done) {
	if (const auto chat = peer->asChat()) {
		for (const auto &user : users) {
			_api.request(MTPmessages_AddChatUser(
				chat->inputChat,
				user->inputUser,
				MTP_int(passGroupHistory ? kForwardMessagesOnAdd : 0)
			)).done([=](const MTPUpdates &result) {
				chat->session().api().applyUpdates(result);
				if (done) done(true);
			}).fail([=](const MTP::Error &error) {
				const auto type = error.type();
				ShowAddParticipantsError(type, peer, { 1, user }, show);
				if (done) done(false);
			}).afterDelay(kSmallDelayMs).send();
		}
	} else if (const auto channel = peer->asChannel()) {
		const auto hasBot = ranges::any_of(users, &UserData::isBot);
		if (!peer->isMegagroup() && hasBot) {
			ShowAddParticipantsError("USER_BOT", peer, users, show);
			return;
		}
		auto list = QVector<MTPInputUser>();
		list.reserve(std::min(int(users.size()), int(kMaxUsersPerInvite)));
		const auto send = [&] {
			const auto callback = base::take(done);
			_api.request(MTPchannels_InviteToChannel(
				channel->inputChannel,
				MTP_vector<MTPInputUser>(list)
			)).done([=](const MTPUpdates &result) {
				channel->session().api().applyUpdates(result);
				requestCountDelayed(channel);
				if (callback) callback(true);
				ChatInviteForbidden(
					show,
					channel,
					CollectForbiddenUsers(&channel->session(), result));
			}).fail([=](const MTP::Error &error) {
				ShowAddParticipantsError(error.type(), peer, users, show);
				if (callback) callback(false);
			}).afterDelay(kSmallDelayMs).send();
		};
		for (const auto &user : users) {
			list.push_back(user->inputUser);
			if (list.size() == kMaxUsersPerInvite) {
				send();
				list.clear();
			}
		}
		if (!list.empty()) {
			send();
		}
	} else {
		Unexpected("User in ChatParticipants::add.");
	}
}

ChatParticipants::Parsed ChatParticipants::Parse(
		not_null<ChannelData*> channel,
		const TLMembers &data) {
	channel->owner().processUsers(data.vusers());
	channel->owner().processChats(data.vchats());
	auto list = ParseList(data, channel);
	if (channel->mgInfo) {
		RefreshChannelAdmins(channel, list);
	}
	return { data.vcount().v, std::move(list) };
}

ChatParticipants::Parsed ChatParticipants::ParseRecent(
		not_null<ChannelData*> channel,
		const TLMembers &data) {
	const auto result = Parse(channel, data);
	const auto applyLast = channel->isMegagroup()
		&& channel->canViewMembers()
		&& (channel->mgInfo->lastParticipants.size() <= result.list.size());
	if (applyLast) {
		ApplyLastList(channel, result.availableCount, result.list);
	}
	return result;
}

void ChatParticipants::requestSelf(not_null<ChannelData*> channel) {
	if (_selfParticipantRequests.contains(channel)) {
		return;
	}

	const auto finalize = [=](
			UserId inviter = -1,
			TimeId inviteDate = 0,
			bool inviteViaRequest = false) {
		channel->inviter = inviter;
		channel->inviteDate = inviteDate;
		channel->inviteViaRequest = inviteViaRequest;
		if (const auto history = channel->owner().historyLoaded(channel)) {
			if (history->lastMessageKnown()) {
				history->checkLocalMessages();
				history->owner().sendHistoryChangeNotifications();
			} else {
				history->owner().histories().requestDialogEntry(history);
			}
		}
	};
	_selfParticipantRequests.emplace(channel);
	_api.request(MTPchannels_GetParticipant(
		channel->inputChannel,
		MTP_inputPeerSelf()
	)).done([=](const MTPchannels_ChannelParticipant &result) {
		_selfParticipantRequests.erase(channel);
		result.match([&](const MTPDchannels_channelParticipant &data) {
			channel->owner().processUsers(data.vusers());

			const auto &participant = data.vparticipant();
			participant.match([&](const MTPDchannelParticipantSelf &data) {
				finalize(
					data.vinviter_id().v,
					data.vdate().v,
					data.is_via_request());
			}, [&](const MTPDchannelParticipantCreator &) {
				if (channel->mgInfo) {
					channel->mgInfo->creator = channel->session().user();
				}
				finalize(channel->session().userId(), channel->date);
			}, [&](const MTPDchannelParticipantAdmin &data) {
				const auto inviter = data.is_self()
					? data.vinviter_id().value_or(-1)
					: -1;
				finalize(inviter, data.vdate().v);
			}, [&](const MTPDchannelParticipantBanned &data) {
				LOG(("API Error: Got self banned participant."));
				finalize();
			}, [&](const MTPDchannelParticipant &data) {
				LOG(("API Error: Got self regular participant."));
				finalize();
			}, [&](const MTPDchannelParticipantLeft &data) {
				LOG(("API Error: Got self left participant."));
				finalize();
			});
		});
	}).fail([=](const MTP::Error &error) {
		_selfParticipantRequests.erase(channel);
		if (error.type() == u"CHANNEL_PRIVATE"_q) {
			channel->privateErrorReceived();
		}
		finalize();
	}).afterDelay(kSmallDelayMs).send();
}

void ChatParticipants::kick(
		not_null<ChatData*> chat,
		not_null<PeerData*> participant) {
	Expects(participant->isUser());

	_api.request(MTPmessages_DeleteChatUser(
		MTP_flags(0),
		chat->inputChat,
		participant->asUser()->inputUser
	)).done([=](const MTPUpdates &result) {
		chat->session().api().applyUpdates(result);
	}).send();
}

void ChatParticipants::kick(
		not_null<ChannelData*> channel,
		not_null<PeerData*> participant,
		ChatRestrictionsInfo currentRights) {
	const auto kick = KickRequest(channel, participant);
	if (_kickRequests.contains(kick)) return;

	const auto rights = ChannelData::KickedRestrictedRights(participant);
	const auto requestId = _api.request(MTPchannels_EditBanned(
		channel->inputChannel,
		participant->input,
		MTP_chatBannedRights(
			MTP_flags(
				MTPDchatBannedRights::Flags::from_raw(uint32(rights.flags))),
			MTP_int(rights.until))
	)).done([=](const MTPUpdates &result) {
		channel->session().api().applyUpdates(result);

		_kickRequests.remove(KickRequest(channel, participant));
		channel->applyEditBanned(participant, currentRights, rights);
	}).fail([this, kick] {
		_kickRequests.remove(kick);
	}).send();

	_kickRequests.emplace(kick, requestId);
}

void ChatParticipants::unblock(
		not_null<ChannelData*> channel,
		not_null<PeerData*> participant) {
	const auto kick = KickRequest(channel, participant);
	if (_kickRequests.contains(kick)) {
		return;
	}

	const auto requestId = _api.request(MTPchannels_EditBanned(
		channel->inputChannel,
		participant->input,
		MTP_chatBannedRights(MTP_flags(0), MTP_int(0))
	)).done([=](const MTPUpdates &result) {
		channel->session().api().applyUpdates(result);

		_kickRequests.remove(KickRequest(channel, participant));
		if (channel->kickedCount() > 0) {
			channel->setKickedCount(channel->kickedCount() - 1);
		} else {
			channel->updateFullForced();
		}
	}).fail([=] {
		_kickRequests.remove(kick);
	}).send();

	_kickRequests.emplace(kick, requestId);
}

void ChatParticipants::loadSimilarChannels(not_null<ChannelData*> channel) {
	if (!channel->isBroadcast()) {
		return;
	} else if (const auto i = _similar.find(channel); i != end(_similar)) {
		if (i->second.requestId
			|| !i->second.channels.more
			|| !channel->session().premium()) {
			return;
		}
	}
	_similar[channel].requestId = _api.request(
		MTPchannels_GetChannelRecommendations(channel->inputChannel)
	).done([=](const MTPmessages_Chats &result) {
		auto &similar = _similar[channel];
		similar.requestId = 0;
		auto parsed = ParseSimilar(channel, result);
		if (similar.channels == parsed) {
			return;
		}
		similar.channels = std::move(parsed);
		if (const auto history = channel->owner().historyLoaded(channel)) {
			if (const auto item = history->joinedMessageInstance()) {
				history->owner().requestItemResize(item);
			}
		}
		_similarLoaded.fire_copy(channel);
	}).send();
}

auto ChatParticipants::similar(not_null<ChannelData*> channel)
-> const Channels & {
	const auto i = channel->isBroadcast()
		? _similar.find(channel)
		: end(_similar);
	if (i != end(_similar)) {
		return i->second.channels;
	}
	static const auto empty = Channels();
	return empty;
}

auto ChatParticipants::similarLoaded() const
-> rpl::producer<not_null<ChannelData*>> {
	return _similarLoaded.events();
}

} // namespace Api
