mtgodot-poc/extension/src/net/classic/classic_session.cpp

#include "classic_session.h"

#include <algorithm>
#include <cstring>
#include <vector>

namespace mtnet::classic {

ClassicSession::ClassicSession() : m_parser(m_world) {
	m_stream.on_phase = [this](uint8_t p) { on_phase(p); };
	m_stream.on_packet = [this](uint8_t h, const uint8_t *b, uint32_t l) {
		return on_packet(h, b, l);
	};
	m_stream.on_error = [this](const std::string &e) {
		m_last_error = e;
		set_stage(Stage::Failed);
		if (on_error) {
			on_error(e);
		}
	};
	m_stream.on_state_change = [this](ClassicStream::State s) {
		if (s == ClassicStream::State::Offline && m_stage != Stage::Failed &&
				m_stage != Stage::Offline) {
			m_last_error = m_stream.last_error().empty() ? "disconnected" : m_stream.last_error();
			set_stage(Stage::Failed);
		} else if (s == ClassicStream::State::Online && m_stage == Stage::Connecting) {
			// handshake packets flow next; stay in Connecting until GC_PHASE(LOGIN)
		}
	};
}

void ClassicSession::set_stage(Stage s) {
	if (m_stage == s) {
		return;
	}
	m_stage = s;
	if (on_stage_change) {
		on_stage_change(s);
	}
}

void ClassicSession::start_offline(const std::string &id, const std::string &pw) {
	m_id = id;
	m_pw = pw;
	m_login_sent = false;
	m_entergame_sent = false;
	m_version_sent = false;
	m_last_error.clear();
	// During PHASE_HANDSHAKE even retry handshakes must be answered with
	// 0xFF. The normal game client switches to CG_TIME_SYNC only after the
	// server has advanced into the login/select side of the connection.
	m_stream.set_time_sync_mode(false);
	set_stage(Stage::Connecting);
}

bool ClassicSession::connect(const std::string &game_host, uint16_t game_port,
		const std::string &id, const std::string &pw) {
	start_offline(id, pw);
	if (!m_stream.connect(game_host, game_port)) {
		m_last_error = m_stream.last_error();
		set_stage(Stage::Failed);
		return false;
	}
	return true;
}

void ClassicSession::disconnect() {
	m_stream.disconnect();
	set_stage(Stage::Offline);
}

void ClassicSession::pump() {
	m_stream.process();
	// auto CG_ENTERGAME a beat into PHASE_LOADING (the m2dev client waits ~1.5s;
	// sending it too early makes the server drop us mid spawn-burst).
	if (m_stage == Stage::Loading && !m_entergame_sent && m_entergame_delay > 0 &&
			m_now - m_loading_since >= m_entergame_delay) {
		enter_game();
	}
	m_world.tick();
}

void ClassicSession::send_login() {
	if (m_login_sent) {
		return;
	}
	// docs §2.2: the client turns sequence mode on around here; CG_LOGIN is a
	// bSeq packet and the server expects the trailing byte from packet #1.
	m_stream.set_sequence_mode(true);

	CGLogin p{};
	p.header = HDR_CG_LOGIN;
	std::strncpy(p.login, m_id.c_str(), sizeof(p.login) - 1);
	std::strncpy(p.passwd, m_pw.c_str(), sizeof(p.passwd) - 1);
	m_stream.send_fixed(&p, sizeof(p));
	m_login_sent = true;
}

bool ClassicSession::create_character(int slot, const std::string &name, int job, int shape,
		int con, int intel, int str, int dex) {
	if (m_stage != Stage::CharSelect || slot < 0 || slot >= m_parser.slot_count() ||
			name.empty() || name.size() > CHARACTER_NAME_MAX_LEN) {
		return false;
	}
	CGPlayerCreate p{};
	p.header = HDR_CG_CHARACTER_CREATE;
	p.index = static_cast<uint8_t>(slot);
	std::memcpy(p.name, name.data(), name.size());
	p.job = static_cast<uint16_t>(job);
	p.shape = static_cast<uint8_t>(shape);
	p.con = static_cast<uint8_t>(con);
	p.intel = static_cast<uint8_t>(intel);
	p.str = static_cast<uint8_t>(str);
	p.dex = static_cast<uint8_t>(dex);
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::delete_character(int slot, const std::string &private_code) {
	if (m_stage != Stage::CharSelect || slot < 0 || slot >= m_parser.slot_count() ||
			private_code.size() > PRIVATE_CODE_LENGTH) {
		return false;
	}
	CGPlayerDelete p{};
	p.header = HDR_CG_CHARACTER_DELETE;
	p.index = static_cast<uint8_t>(slot);
	std::memcpy(p.private_code, private_code.data(), private_code.size());
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::change_name(int slot, const std::string &name) {
	if (m_stage != Stage::CharSelect || slot < 0 || slot >= m_parser.slot_count() ||
			name.empty() || name.size() > CHARACTER_NAME_MAX_LEN) {
		return false;
	}
	CGChangeName p{};
	p.header = HDR_CG_CHANGE_NAME;
	p.index = static_cast<uint8_t>(slot);
	std::memcpy(p.name, name.data(), name.size());
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_empire(uint8_t empire) {
	if (m_stage != Stage::CharSelect) {
		return false;
	}
	CGEmpire p{HDR_CG_EMPIRE, empire};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_client_version() {
	if (m_version_sent) {
		return true;
	}
	CGClientVersion p{};
	// The stock 40250 game client sends the version report immediately after
	// receiving the main-character packet and advances the normal CG sequence.
	p.header = HDR_CG_CLIENT_VERSION;
	std::strncpy(p.filename, "metin2.bin", sizeof(p.filename) - 1);
	std::strncpy(p.timestamp, "1215955205", sizeof(p.timestamp) - 1);
	if (!m_stream.send_fixed(&p, sizeof(p))) {
		return false;
	}
	m_version_sent = true;
	return true;
}

void ClassicSession::on_phase(uint8_t phase) {
	if (phase == PHASE_LOGIN || phase == PHASE_SELECT || phase == PHASE_LOADING ||
			phase == PHASE_GAME || phase == PHASE_DEAD) {
		m_stream.set_time_sync_mode(true);
	}
	switch (phase) {
		case PHASE_LOGIN:
			set_stage(Stage::LoggingIn);
			send_login();
			break;
		case PHASE_SELECT:
			set_stage(Stage::CharSelect);
			if (m_parser.char_list_ready() && on_char_list) {
				on_char_list(m_parser.char_slots());
			}
			break;
		case PHASE_LOADING:
			set_stage(Stage::Loading);
			m_loading_since = m_now;
			m_entergame_sent = false;
			break;
		case PHASE_GAME:
			set_stage(Stage::InGame);
			if (on_entered_game) {
				on_entered_game();
			}
			break;
		case PHASE_CLOSE:
			m_last_error = m_last_error.empty() ? "server closed phase" : m_last_error;
			set_stage(Stage::Failed);
			break;
		default:
			break;
	}
}

bool ClassicSession::on_packet(uint8_t header, const uint8_t *body, uint32_t len) {
	if (!m_parser.on_gc(header, body, len)) {
		m_last_error = "parse error on GC header " + std::to_string(header);
		return false;
	}
	if ((header == HDR_GC_MAIN_CHARACTER || header == HDR_GC_MAIN_CHARACTER3_BGM ||
			header == HDR_GC_MAIN_CHARACTER4_BGM_VOL) && !send_client_version()) {
		m_last_error = "failed to send client version";
		return false;
	}
	if (!m_parser.login_failure().empty() && m_stage == Stage::LoggingIn) {
		m_last_error = "login failed: " + m_parser.login_failure();
		set_stage(Stage::Failed);
		return false;
	}
	return true;
}

bool ClassicSession::select_char(int slot) {
	// Caller-side misuse: return false but don't poison m_last_error, which is
	// reserved for transport/protocol failures ("is the connection healthy").
	if (m_stage != Stage::CharSelect) {
		return false;
	}
	if (slot < 0 || slot >= m_parser.slot_count()) {
		return false;
	}
	CGPlayerSelect p{};
	p.header = HDR_CG_CHARACTER_SELECT;
	p.player_index = static_cast<uint8_t>(slot);
	m_stream.send_fixed(&p, sizeof(p));
	return true;
}

bool ClassicSession::enter_game() {
	if (m_entergame_sent) {
		return true;
	}
	CGEnterGame p{};
	p.header = HDR_CG_ENTERGAME;
	m_stream.send_fixed(&p, sizeof(p));
	m_entergame_sent = true;
	return true;
}

// --- in-game intents ---------------------------------------------------------

bool ClassicSession::send_move(uint8_t func, uint8_t arg, float rot_deg, int32_t x, int32_t y,
		uint32_t time_ms) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGMove p{};
	p.header = HDR_CG_MOVE;
	p.func = func;
	p.arg = arg;
	p.rot = static_cast<uint8_t>(rot_deg / 5.0f); // classic wire: bRot = deg/5
	p.x = x;
	p.y = y;
	p.time = time_ms ? time_ms : m_now;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_attack(uint8_t type, uint32_t victim_vid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGAttack p{};
	p.header = HDR_CG_ATTACK;
	p.type = type;
	p.victim_vid = victim_vid;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_chat(uint8_t type, const std::string &text) {
	if (m_stage != Stage::InGame || text.empty() || text.size() >= 512) {
		return false;
	}
	// wire: [header][WORD length][BYTE type][text\0]; length = 4 + strlen + 1
	const uint16_t len = static_cast<uint16_t>(sizeof(CGChatHead) + text.size() + 1);
	std::vector<uint8_t> buf(len, 0);
	CGChatHead h{};
	h.header = HDR_CG_CHAT;
	h.length = len;
	h.type = type;
	std::memcpy(buf.data(), &h, sizeof(h));
	std::memcpy(buf.data() + sizeof(h), text.data(), text.size());
	// buf[len-1] stays 0 (the trailing NUL)
	return m_stream.send_dynamic(buf.data(), buf.size());
}

bool ClassicSession::send_target(uint32_t vid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGTarget p{HDR_CG_TARGET, vid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_character_position(uint8_t position) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGPosition p{HDR_CG_CHARACTER_POSITION, position};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_click_npc(uint32_t vid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGOnClick p{HDR_CG_ON_CLICK, vid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_script_answer(uint8_t answer) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGScriptAnswer p{HDR_CG_SCRIPT_ANSWER, answer};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_item_use(uint8_t window, uint16_t cell) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGItemUse p{};
	p.header = HDR_CG_ITEM_USE;
	p.pos = {window, cell};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_item_move(uint8_t window, uint16_t cell, uint8_t to_window,
		uint16_t to_cell, uint8_t count) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGItemMove p{};
	p.header = HDR_CG_ITEM_MOVE;
	p.pos = {window, cell};
	p.change_pos = {to_window, to_cell};
	p.num = count;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_item_drop(uint8_t window, uint16_t cell, uint32_t gold, uint8_t count) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	if (count > 0) {
		CGItemDrop2 p{};
		p.header = HDR_CG_ITEM_DROP2;
		p.pos = {window, cell};
		p.gold = gold;
		p.count = count;
		return m_stream.send_fixed(&p, sizeof(p));
	}
	CGItemDrop p{};
	p.header = HDR_CG_ITEM_DROP;
	p.pos = {window, cell};
	p.gold = gold;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_item_pickup(uint32_t ground_vid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGItemPickup p{HDR_CG_ITEM_PICKUP, ground_vid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_use_skill(uint32_t skill_vnum, uint32_t target_vid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	if (target_vid) {
		CGFlyTargeting ft{};
		ft.header = HDR_CG_FLY_TARGETING;
		ft.target_vid = target_vid;
		m_stream.send_fixed(&ft, sizeof(ft));
	}
	CGUseSkill p{};
	p.header = HDR_CG_USE_SKILL;
	p.vnum = skill_vnum;
	p.target_vid = target_vid;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_item_use_to_item(uint8_t window, uint16_t cell, uint8_t target_window,
		uint16_t target_cell) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGItemUseToItem p{};
	p.header = HDR_CG_ITEM_USE_TO_ITEM;
	p.pos = {window, cell};
	p.target_pos = {target_window, target_cell};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_item_give(uint32_t target_vid, uint8_t window, uint16_t cell,
		uint8_t count) {
	if (m_stage != Stage::InGame || target_vid == 0 || count == 0) {
		return false;
	}
	CGGiveItem p{};
	p.header = HDR_CG_ITEM_GIVE;
	p.target_vid = target_vid;
	p.pos = {window, cell};
	p.count = count;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_request_warp() {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGWarp p{HDR_CG_WARP};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_fishing(uint8_t rot) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGFishing p{HDR_CG_FISHING, rot};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_dungeon() {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGWarp p{HDR_CG_DUNGEON};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_sync_positions(const std::vector<SyncPosElement> &positions) {
	if (m_stage != Stage::InGame || positions.empty() || positions.size() > 16) {
		return false;
	}
	const size_t total = sizeof(DynHead) + positions.size() * sizeof(SyncPosElement);
	if (total > 0xffffu) {
		return false;
	}
	std::vector<uint8_t> buf(total, 0);
	DynHead head{HDR_CG_SYNC_POSITION, static_cast<uint16_t>(total)};
	std::memcpy(buf.data(), &head, sizeof(head));
	std::memcpy(buf.data() + sizeof(head), positions.data(),
			positions.size() * sizeof(SyncPosElement));
	return m_stream.send_fixed(buf.data(), buf.size());
}

bool ClassicSession::send_whisper(const std::string &to, const std::string &text) {
	if (m_stage != Stage::InGame || to.empty() || to.size() > CHARACTER_NAME_MAX_LEN ||
			text.empty() || text.size() >= 512) {
		return false;
	}
	const size_t total = sizeof(CGWhisper) + text.size() + 1;
	if (total > 0xffffu) {
		return false;
	}
	std::vector<uint8_t> buf(total, 0);
	CGWhisper p{};
	p.header = HDR_CG_WHISPER;
	p.size = static_cast<uint16_t>(total);
	std::memcpy(p.name_to, to.data(), to.size());
	std::memcpy(buf.data(), &p, sizeof(p));
	std::memcpy(buf.data() + sizeof(p), text.data(), text.size());
	return m_stream.send_dynamic(buf.data(), buf.size());
}

bool ClassicSession::send_shoot(uint8_t type) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGShoot p{HDR_CG_SHOOT, type};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_add_fly_targeting(uint32_t target_vid, int32_t x, int32_t y) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGFlyTargeting p{HDR_CG_ADD_FLY_TARGETING, target_vid, x, y};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_quickslot_add(uint8_t pos, uint8_t type, uint8_t ref) {
	if (m_stage != Stage::InGame || pos >= QUICKSLOT_MAX_NUM) {
		return false;
	}
	CGQuickSlotAdd p{HDR_CG_QUICKSLOT_ADD, pos, type, ref};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_quickslot_del(uint8_t pos) {
	if (m_stage != Stage::InGame || pos >= QUICKSLOT_MAX_NUM) {
		return false;
	}
	CGQuickSlotDel p{HDR_CG_QUICKSLOT_DEL, pos};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_quickslot_swap(uint8_t pos, uint8_t pos_to) {
	if (m_stage != Stage::InGame || pos >= QUICKSLOT_MAX_NUM || pos_to >= QUICKSLOT_MAX_NUM) {
		return false;
	}
	CGQuickSlotSwap p{HDR_CG_QUICKSLOT_SWAP, pos, pos_to};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_script_button(uint32_t index) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGScriptButton p{HDR_CG_SCRIPT_BUTTON, index};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_script_select_item(uint32_t selection) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGScriptSelectItem p{HDR_CG_SCRIPT_SELECT_ITEM, selection};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_quest_input(const std::string &text) {
	if (m_stage != Stage::InGame || text.size() > 64) {
		return false;
	}
	CGQuestInput p{};
	p.header = HDR_CG_QUEST_INPUT_STRING;
	std::memcpy(p.msg, text.data(), text.size());
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_quest_confirm(bool yes, uint32_t request_pid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGQuestConfirm p{HDR_CG_QUEST_CONFIRM, static_cast<uint8_t>(yes ? 1 : 0), request_pid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_quest_cancel() {
	// The classic protocol has no separate CG_QUEST_CANCEL header. The stock
	// client closes a script by answering 255 (the same sentinel exposed by
	// script_answer()) and the server routes it through ScriptAnswer.
	return send_script_answer(255);
}

bool ClassicSession::send_party_invite(uint32_t vid) {
	if (m_stage != Stage::InGame || vid == 0) return false;
	CGPartyInvite p{HDR_CG_PARTY_INVITE, vid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_party_answer(uint32_t leader_vid, bool accept) {
	if (m_stage != Stage::InGame || leader_vid == 0) return false;
	CGPartyInviteAnswer p{HDR_CG_PARTY_INVITE_ANSWER, leader_vid,
			static_cast<uint8_t>(accept ? 1 : 0)};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_party_remove(uint32_t pid) {
	if (m_stage != Stage::InGame || pid == 0) return false;
	CGPartyRemove p{HDR_CG_PARTY_REMOVE, pid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_party_set_state(uint32_t pid, uint8_t role, bool on) {
	if (m_stage != Stage::InGame || pid == 0) return false;
	CGPartySetState p{HDR_CG_PARTY_SET_STATE, pid, role, static_cast<uint8_t>(on ? 1 : 0)};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_party_use_skill(uint8_t skill_index, uint32_t vid) {
	if (m_stage != Stage::InGame) return false;
	CGPartyUseSkill p{HDR_CG_PARTY_USE_SKILL, skill_index, vid};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_party_parameter(uint8_t mode) {
	if (m_stage != Stage::InGame) return false;
	CGPartyParameter p{HDR_CG_PARTY_PARAMETER, mode};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_shop_buy(uint8_t pos, uint8_t count) {
	if (m_stage != Stage::InGame) return false;
	uint8_t buf[sizeof(CGShop) + sizeof(CGShopBuy)] = {};
	CGShop head{HDR_CG_SHOP, SHOP_CG_BUY};
	CGShopBuy body{count, pos};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &body, sizeof(body));
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_shop_sell(uint8_t pos, uint8_t count) {
	if (m_stage != Stage::InGame) return false;
	if (count == 0) {
		uint8_t buf[sizeof(CGShop) + sizeof(CGShopSell)] = {};
		CGShop head{HDR_CG_SHOP, SHOP_CG_SELL};
		CGShopSell body{pos};
		std::memcpy(buf, &head, sizeof(head));
		std::memcpy(buf + sizeof(head), &body, sizeof(body));
		return m_stream.send_fixed(buf, sizeof(buf));
	}
	uint8_t buf[sizeof(CGShop) + sizeof(CGShopSell2)] = {};
	CGShop head{HDR_CG_SHOP, SHOP_CG_SELL2};
	CGShopSell2 body{pos, count};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &body, sizeof(body));
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_shop_close() {
	if (m_stage != Stage::InGame) return false;
	CGShop p{HDR_CG_SHOP, SHOP_CG_END};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_private_shop(const std::string &sign,
		const std::vector<CGMyShopItem> &items) {
	if (m_stage != Stage::InGame || sign.size() > SHOP_TAB_NAME_MAX) return false;
	const size_t n = std::min(items.size(), static_cast<size_t>(39));
	const size_t total = sizeof(CGMyShopHead) + n * sizeof(CGMyShopItem);
	std::vector<uint8_t> buf(total, 0);
	CGMyShopHead head{};
	head.header = HDR_CG_MYSHOP;
	std::memcpy(head.sign, sign.data(), sign.size());
	head.count = static_cast<uint8_t>(n);
	std::memcpy(buf.data(), &head, sizeof(head));
	if (n > 0) {
		std::memcpy(buf.data() + sizeof(head), items.data(), n * sizeof(CGMyShopItem));
	}
	return m_stream.send_fixed(buf.data(), buf.size());
}

bool ClassicSession::send_cube_make(int result_index) {
	// 40250's command handler ignores a recipe index: an argument means
	// "make all" while no argument makes one recipe from the currently loaded
	// cube slots.  Never send the index through as it would unexpectedly craft
	// repeatedly and consume every matching material.
	(void)result_index;
	return send_chat(0, "/cube make");
}

bool ClassicSession::send_cube_result_list(int npc_vnum) {
	(void)npc_vnum; // 40250 derives the active NPC from the selected cube context.
	return send_chat(0, "/cube r_info");
}

bool ClassicSession::send_cube_materials(int start_index, int count) {
	if (start_index < 0 || count < 1 || start_index > 255 || count > 255) return false;
	return send_chat(0, "/cube r_info " + std::to_string(start_index) + " " +
			std::to_string(count));
}

bool ClassicSession::send_cube_open() {
	return send_chat(0, "/cube open");
}

bool ClassicSession::send_cube_close() {
	return send_chat(0, "/cube close");
}

bool ClassicSession::send_cube_list() {
	return send_chat(0, "/cube list");
}

bool ClassicSession::send_cube_add_item(int cube_index, int inventory_index) {
	if (cube_index < 0 || cube_index >= 24 || inventory_index < 0 || inventory_index > 255) {
		return false;
	}
	return send_chat(0, "/cube add " + std::to_string(cube_index) + " " +
			std::to_string(inventory_index));
}

bool ClassicSession::send_cube_delete_item(int cube_index) {
	if (cube_index < 0 || cube_index >= 24) return false;
	return send_chat(0, "/cube delete " + std::to_string(cube_index));
}

bool ClassicSession::send_guild_sub(uint8_t subheader) {
	if (m_stage != Stage::InGame) return false;
	CGGuild p{HDR_CG_GUILD, subheader};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_guild_u32(uint8_t subheader, uint32_t value) {
	if (m_stage != Stage::InGame) return false;
	uint8_t buf[sizeof(CGGuild) + sizeof(value)] = {};
	CGGuild head{HDR_CG_GUILD, subheader};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &value, sizeof(value));
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_i32(uint8_t subheader, int32_t value) {
	if (m_stage != Stage::InGame) return false;
	uint8_t buf[sizeof(CGGuild) + sizeof(value)] = {};
	CGGuild head{HDR_CG_GUILD, subheader};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &value, sizeof(value));
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_grade_name(uint8_t grade, const std::string &name) {
	if (m_stage != Stage::InGame || grade == 0 || grade >= 16 || name.empty() ||
			name.size() > GUILD_GRADE_NAME_MAX_LEN) return false;
	uint8_t buf[sizeof(CGGuild) + 1 + GUILD_GRADE_NAME_MAX_LEN + 1] = {};
	CGGuild head{HDR_CG_GUILD, GUILD_CG_CHANGE_GRADE_NAME};
	std::memcpy(buf, &head, sizeof(head));
	buf[sizeof(head)] = grade;
	std::memcpy(buf + sizeof(head) + 1, name.data(), name.size());
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_grade_authority(uint8_t grade, uint8_t authority) {
	if (m_stage != Stage::InGame || grade == 0 || grade >= 16) return false;
	uint8_t buf[sizeof(CGGuild) + 2] = {};
	CGGuild head{HDR_CG_GUILD, GUILD_CG_CHANGE_GRADE_AUTHORITY};
	std::memcpy(buf, &head, sizeof(head));
	buf[sizeof(head)] = grade;
	buf[sizeof(head) + 1] = authority;
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_member_grade(uint32_t pid, uint8_t grade) {
	if (m_stage != Stage::InGame || pid == 0 || grade == 0 || grade >= 16) return false;
	uint8_t buf[sizeof(CGGuild) + sizeof(pid) + 1] = {};
	CGGuild head{HDR_CG_GUILD, GUILD_CG_CHANGE_MEMBER_GRADE};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &pid, sizeof(pid));
	buf[sizeof(head) + sizeof(pid)] = grade;
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_member_general(uint32_t pid, bool enabled) {
	if (m_stage != Stage::InGame || pid == 0) return false;
	uint8_t buf[sizeof(CGGuild) + sizeof(pid) + 1] = {};
	CGGuild head{HDR_CG_GUILD, GUILD_CG_CHANGE_MEMBER_GENERAL};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &pid, sizeof(pid));
	buf[sizeof(head) + sizeof(pid)] = enabled ? 1 : 0;
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_comment(const std::string &text) {
	if (m_stage != Stage::InGame || text.empty() ||
			text.size() + 1 > GUILD_COMMENT_MAX_LEN) return false;
	std::vector<uint8_t> buf(sizeof(CGGuild) + 1 + text.size() + 1, 0);
	CGGuild head{HDR_CG_GUILD, GUILD_CG_POST_COMMENT};
	std::memcpy(buf.data(), &head, sizeof(head));
	buf[sizeof(head)] = static_cast<uint8_t>(text.size() + 1);
	if (!text.empty()) {
		std::memcpy(buf.data() + sizeof(head) + 1, text.data(), text.size());
	}
	return m_stream.send_fixed(buf.data(), buf.size());
}

bool ClassicSession::send_guild_invite_answer(uint32_t guild_id, bool accept) {
	if (m_stage != Stage::InGame) return false;
	uint8_t buf[sizeof(CGGuild) + sizeof(guild_id) + 1] = {};
	CGGuild head{HDR_CG_GUILD, GUILD_CG_GUILD_INVITE_ANSWER};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &guild_id, sizeof(guild_id));
	buf[sizeof(head) + sizeof(guild_id)] = accept ? 1 : 0;
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_guild_answer_make(const std::string &name) {
	if (m_stage != Stage::InGame || name.empty() || name.size() > GUILD_NAME_MAX_LEN) return false;
	CGAnswerMakeGuild p{};
	p.header = HDR_CG_ANSWER_MAKE_GUILD;
	std::memcpy(p.guild_name, name.data(), name.size());
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_guild_skill(uint32_t skill_vnum, uint32_t target_pid) {
	if (m_stage != Stage::InGame) return false;
	uint8_t buf[sizeof(CGGuild) + sizeof(CGGuildUseSkill)] = {};
	CGGuild head{HDR_CG_GUILD, GUILD_CG_USE_SKILL};
	CGGuildUseSkill body{skill_vnum, target_pid};
	std::memcpy(buf, &head, sizeof(head));
	std::memcpy(buf + sizeof(head), &body, sizeof(body));
	return m_stream.send_fixed(buf, sizeof(buf));
}

bool ClassicSession::send_refine(uint8_t pos, uint8_t type) {
	if (m_stage != Stage::InGame) return false;
	CGRefine p{HDR_CG_REFINE, pos, type};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_dragon_soul_refine(uint8_t subheader, const ItemPos *grid, size_t count) {
	if (m_stage != Stage::InGame || !grid || count > DS_REFINE_GRID_MAX_NUM) return false;
	CGDragonSoulRefine p{};
	p.header = HDR_CG_DRAGON_SOUL_REFINE;
	p.subheader = subheader;
	std::memcpy(p.grid, grid, count * sizeof(ItemPos));
	return m_stream.send_fixed(&p, sizeof(p));
}

namespace {
bool valid_character_name(const std::string &name) {
	return !name.empty() && name.size() < CHARACTER_NAME_MAX_LEN;
}
}

bool ClassicSession::send_friend_add(const std::string &name) {
	if (m_stage != Stage::InGame || !valid_character_name(name)) {
		return false;
	}
	// Messenger's extra payload is not length-prefixed: the server consumes a
	// fixed CHARACTER_NAME_MAX_LEN byte buffer after the two-byte base header.
	std::vector<uint8_t> buf(sizeof(CGMessenger) + CHARACTER_NAME_MAX_LEN, 0);
	CGMessenger p{HDR_CG_MESSENGER, MESSENGER_CG_ADD_BY_NAME};
	std::memcpy(buf.data(), &p, sizeof(p));
	std::memcpy(buf.data() + sizeof(p), name.data(), name.size());
	return m_stream.send_fixed(buf.data(), buf.size());
}

bool ClassicSession::send_friend_remove(const std::string &name) {
	if (m_stage != Stage::InGame || !valid_character_name(name)) {
		return false;
	}
	std::vector<uint8_t> buf(sizeof(CGMessenger) + CHARACTER_NAME_MAX_LEN, 0);
	CGMessenger p{HDR_CG_MESSENGER, MESSENGER_CG_REMOVE};
	std::memcpy(buf.data(), &p, sizeof(p));
	std::memcpy(buf.data() + sizeof(p), name.data(), name.size());
	return m_stream.send_fixed(buf.data(), buf.size());
}

bool ClassicSession::send_exchange_start(uint32_t partner_vid) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGExchange p{};
	p.header = HDR_CG_EXCHANGE;
	p.subheader = EXCHANGE_CG_START;
	p.arg1 = partner_vid;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_exchange_item_add(uint8_t inv_window, uint16_t inv_cell,
		uint8_t display_pos) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGExchange p{};
	p.header = HDR_CG_EXCHANGE;
	p.subheader = EXCHANGE_CG_ITEM_ADD;
	p.arg2 = display_pos;
	p.pos = {inv_window, inv_cell};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_exchange_gold(uint32_t gold) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGExchange p{};
	p.header = HDR_CG_EXCHANGE;
	p.subheader = EXCHANGE_CG_GOLD_ADD;
	p.arg1 = gold;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_exchange_accept() {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGExchange p{};
	p.header = HDR_CG_EXCHANGE;
	p.subheader = EXCHANGE_CG_ACCEPT;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_exchange_cancel() {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGExchange p{};
	p.header = HDR_CG_EXCHANGE;
	p.subheader = EXCHANGE_CG_CANCEL;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_safebox_checkin(uint8_t safe_pos, uint8_t inv_window,
		uint16_t inv_cell) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGSafeboxCheckin p{};
	p.header = HDR_CG_SAFEBOX_CHECKIN;
	p.safe_pos = safe_pos;
	p.item_pos = {inv_window, inv_cell};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_safebox_checkout(uint8_t safe_pos, uint8_t inv_window,
		uint16_t inv_cell) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGSafeboxCheckout p{};
	p.header = HDR_CG_SAFEBOX_CHECKOUT;
	p.safe_pos = safe_pos;
	p.item_pos = {inv_window, inv_cell};
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_safebox_move(uint16_t from_cell, uint16_t to_cell, uint8_t count) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGItemMove p{};
	p.header = HDR_CG_SAFEBOX_ITEM_MOVE;
	// The stock 40250 client sends inventory-window positions; the active
	// safebox context tells the server these positions refer to the safebox.
	p.pos = {WINDOW_INVENTORY, from_cell};
	p.change_pos = {WINDOW_INVENTORY, to_cell};
	p.num = count;
	return m_stream.send_fixed(&p, sizeof(p));
}

bool ClassicSession::send_mall_checkout(uint8_t mall_pos, uint8_t inv_window,
		uint16_t inv_cell) {
	if (m_stage != Stage::InGame) {
		return false;
	}
	CGMallCheckout p{};
	p.header = HDR_CG_MALL_CHECKOUT;
	p.mall_pos = mall_pos;
	p.item_pos = {inv_window, inv_cell};
	return m_stream.send_fixed(&p, sizeof(p));
}

} // namespace mtnet::classic