玩家摆摊：个人商铺的挂售系统

local STALL_MAX = 6
local function listItem(actor, slot, item, price)
    local used = 0
    for s = 1, STALL_MAX do
        if getplayvar(actor, "stall_" .. s) then
            used = used + 1
        end
    end
    if used >= STALL_MAX then
        sendmsg(actor, 1, "摊位已满 " .. STALL_MAX .. " 格")
        return
    end
    setplayvar(actor, "stall_" .. slot, item .. "|" .. price)
    sendmsg(actor, 1, item .. " 已上架，定价 " .. price)
end
local function buyStall(buyer, seller, slot)
    local p = getplayerbyname(seller)
    local data = getplayvar(p, "stall_" .. slot)
    if data == nil then return end
    local item, price = data:match("([^|]+)|(.+)")
    price = tonumber(price)
    if (getplayvar(buyer, "GOLD") or 0) < price then
        sendmsg(buyer, 1, "金币不足")
        return
    end
    setplayvar(buyer, "GOLD",
        getplayvar(buyer, "GOLD") - price)
    setplayvar(p, "GOLD",
        (getplayvar(p, "GOLD") or 0) + price)
    setplayvar(p, "stall_" .. slot, nil)
    giveitem(buyer, item, 1)
end

local function closeStall(actor)
    for s = 1, 6 do
        setplayvar(actor, "stall_" .. s, nil)
    end
    sendmsg(actor, 1, "摊位已收，全部商品退回背包")
end