【网络通信】NPC 对话协议：菜单交互的请求响应

---NPC 菜单的下发：项与编号绑定
function Npc.menu(actor, npcId)
    local player = getplayerbyname(actor)
    if not player then return end
    -- 距离校验：远离 NPC 的对话无效
    if Npc.dist(player, npcId) > 5 then
        sendmsg(player, 1, "距离太远，走近些再对话")
        return
    end
    local items = {
        "查看装备店", "出售物品", "行会仓库", "任务委托",
    }
    Npc.send(player, npcId, "铁匠老板：需要点什么？", items)
end

---选择的处理：会话校验后执行
function Npc.onSelect(actor, npcId, idx)
    local player = getplayerbyname(actor)
    if not player then return end
    -- 会话校验：30 秒内未对话过的选择无效
    local sess = Npc.session(player)
    if not sess or sess.npcId ~= npcId
        or os.time() - sess.at > 30 then
        sendmsg(player, 1, "对话已超时，请重新打开菜单")
        return
    end
    if idx == 1 then
        Npc.openShop(player, npcId)
    elseif idx == 2 then
        Npc.openSell(player, npcId)
    elseif idx == 3 then
        callscript(player, "guild_repo")
    elseif idx == 4 then
        Npc.openQuest(player, npcId)
    end
end