【进阶实战】砍价购买：NPC商店的议价尝试封装

local function tryBargain(actor, goodsName)
    local key = "BargainCnt_" .. math.floor(os.time() / 86400)
    local cnt = tonumber(getplayvar(actor, 1, key)) or 0
    if cnt >= 3 then
        sendmsg(actor, 1, "今日议价机会已用完。")
        return nil
    end
    setplayvar(actor, 1, key, cnt + 1, 1)
    local rate = 60 - cnt * 15
    if math.random(1, 100) <= rate then
        local cut = math.random(5, 15)
        sendmsg(actor, 1, goodsName .. " 砍价成功，便宜 " .. cut .. "%！")
        return 100 - cut
    end
    sendmsg(actor, 1, "老板摇头不肯让价。")
    return nil
end

local function buyGoods(actor, goodsName, basePrice)
    local pricePct = tryBargain(actor, goodsName) or 100
    local price = math.max(math.floor(basePrice * pricePct / 100), 1)
    takeitem(actor, "金币", price, 0, "购买" .. goodsName)
    giveitem(actor, goodsName, 1, 0, "商店购得")
    sendmsg(actor, 1, "成交价 " .. price .. " 金币。")
end