tdesktop/Telegram/SourceFiles/data/data_msg_id.h

/*
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
*/
#pragma once

#include "data/data_peer_id.h"

struct MsgId {
	constexpr MsgId() noexcept = default;
	constexpr MsgId(int64 value) noexcept : bare(value) {
	}

	friend inline constexpr auto operator<=>(MsgId, MsgId) = default;

	[[nodiscard]] constexpr explicit operator bool() const noexcept {
		return (bare != 0);
	}
	[[nodiscard]] constexpr bool operator!() const noexcept {
		return !bare;
	}
	[[nodiscard]] constexpr MsgId operator-() const noexcept {
		return -bare;
	}
	constexpr MsgId operator++() noexcept {
		return ++bare;
	}
	constexpr MsgId operator++(int) noexcept {
		return bare++;
	}
	constexpr MsgId operator--() noexcept {
		return --bare;
	}
	constexpr MsgId operator--(int) noexcept {
		return bare--;
	}

	int64 bare = 0;
};

Q_DECLARE_METATYPE(MsgId);

[[nodiscard]] inline constexpr MsgId operator+(MsgId a, MsgId b) noexcept {
	return MsgId(a.bare + b.bare);
}

[[nodiscard]] inline constexpr MsgId operator-(MsgId a, MsgId b) noexcept {
	return MsgId(a.bare - b.bare);
}

constexpr auto StartClientMsgId = MsgId(0x01 - (1LL << 58));
constexpr auto EndClientMsgId = MsgId(-(1LL << 57));
constexpr auto ServerMaxMsgId = MsgId(1LL << 56);
constexpr auto ScheduledMsgIdsRange = (1LL << 32);
constexpr auto ShowAtUnreadMsgId = MsgId(0);

constexpr auto SpecialMsgIdShift = EndClientMsgId.bare;
constexpr auto ShowAtTheEndMsgId = MsgId(SpecialMsgIdShift + 1);
constexpr auto SwitchAtTopMsgId = MsgId(SpecialMsgIdShift + 2);
constexpr auto ShowAndStartBotMsgId = MsgId(SpecialMsgIdShift + 4);
constexpr auto ShowForChooseMessagesMsgId = MsgId(SpecialMsgIdShift + 6);

static_assert(SpecialMsgIdShift + 0xFF < 0);
static_assert(-(SpecialMsgIdShift + 0xFF) > ServerMaxMsgId);

[[nodiscard]] constexpr inline bool IsClientMsgId(MsgId id) noexcept {
	return (id >= StartClientMsgId && id < EndClientMsgId);
}

[[nodiscard]] constexpr inline bool IsServerMsgId(MsgId id) noexcept {
	return (id > 0 && id < ServerMaxMsgId);
}

struct MsgRange {
	constexpr MsgRange() noexcept = default;
	constexpr MsgRange(MsgId from, MsgId till) noexcept
	: from(from)
	, till(till) {
	}

	friend inline constexpr bool operator==(MsgRange, MsgRange) = default;

	MsgId from = 0;
	MsgId till = 0;
};

struct FullMsgId {
	constexpr FullMsgId() noexcept = default;
	constexpr FullMsgId(PeerId peer, MsgId msg) noexcept
	: peer(peer), msg(msg) {
	}
	FullMsgId(ChannelId channelId, MsgId msgId) = delete;

	friend inline constexpr auto operator<=>(FullMsgId, FullMsgId) = default;

	constexpr explicit operator bool() const noexcept {
		return msg != 0;
	}
	constexpr bool operator!() const noexcept {
		return msg == 0;
	}

	PeerId peer = 0;
	MsgId msg = 0;
};

Q_DECLARE_METATYPE(FullMsgId);

struct GlobalMsgId {
	FullMsgId itemId;
	uint64 sessionUniqueId = 0;

	friend inline constexpr auto operator<=>(
		GlobalMsgId,
		GlobalMsgId) = default;

	constexpr explicit operator bool() const noexcept {
		return itemId && sessionUniqueId;
	}
	constexpr bool operator!() const noexcept {
		return !itemId || !sessionUniqueId;
	}
};

namespace std {

template <>
struct hash<MsgId> : private hash<int64> {
	size_t operator()(MsgId value) const noexcept {
		return hash<int64>::operator()(value.bare);
	}
};

} // namespace std