Function WhoReacted

Telegram/SourceFiles/api/api_who_reacted.cpp:594–699

}

rpl::producer<Ui::WhoReadContent> WhoReacted(
		not_null<HistoryItem*> item,
		const ReactionId &reaction,
		not_null<QWidget*> context,
		const style::WhoRead &st,
		std::shared_ptr<WhoReadList> whoReadIds) {
	const auto small = st.userpics.size;
	const auto large = st.photoSize;
	return [=](auto consumer) {
		auto lifetime = rpl::lifetime();

		const auto resolveWhoRead = reaction.empty()
			&& WhoReadExists(item);

		const auto state = lifetime.make_state<State>();
		const auto pushNext = [=] {
			consumer.put_next_copy(state->current);
		};

		const auto resolveWhoReacted = !reaction.empty()
			|| item->canViewReactions();
		auto idsWithReactions = (resolveWhoRead && resolveWhoReacted)
			? WhoReadOrReactedIds(item, context)
			: resolveWhoRead
			? (WhoReadIds(item, context) | rpl::map(WithEmptyReactions))
			: WhoReactedIds(item, reaction, context);
		state->current.type = resolveWhoRead
			? DetectSeenType(item)
			: Ui::WhoReadType::Reacted;
		if (resolveWhoReacted) {
			const auto &list = item->reactions();
			state->current.fullReactionsCount = [&] {
				if (reaction.empty()) {
					return ranges::accumulate(
						list,
						0,
						ranges::plus{},
						&Data::MessageReaction::count);
				}
				const auto i = ranges::find(
					list,
					reaction,
					&Data::MessageReaction::id);
				return (i != end(list)) ? i->count : 0;
			}();
			state->current.singleCustomEntityData = ReactionEntityData(
				!reaction.empty()
				? reaction
				: (list.size() == 1)
				? list.front().id
				: ReactionId());
		}
		std::move(
			idsWithReactions
		) | rpl::on_next([=](PeersWithReactions &&peers) {
			if (peers.state == WhoReadState::Unknown) {
				state->userpics.clear();
				consumer.put_next(Ui::WhoReadContent{