聚宝盆：每日投币的七日翻倍

local function potCoin(actor)
    local today = os.date("%Y%m%d")
    if getplayvar(actor, "potDay") == today then
        sendmsg(actor, 1, "今日已投过")
        return
    end
    if (getplayvar(actor, "GOLD") or 0) < 5000 then
        sendmsg(actor, 1, "金币不足 5000")
        return
    end
    setplayvar(actor, "GOLD",
        (getplayvar(actor, "GOLD") or 0) - 5000)
    setplayvar(actor, "potDay", today)
    local days = (getplayvar(actor, "potDays") or 0) + 1
    setplayvar(actor, "potDays", days)
    sendmsg(actor, 1, "投币成功，已投 "
        .. days .. "/7 天")
end

local function potOpen(actor)
    if (getplayvar(actor, "potDays") or 0) < 7 then
        sendmsg(actor, 1, "未投满 7 天")
        return
    end
    setplayvar(actor, "potDays", 0)
    local mult = math.random(80, 200) / 100
    local payout = math.floor(5000 * 7 * mult)
    giveitem(actor, 9021, payout)
    sendmsg(actor, 1, "聚宝盆开出 " .. payout .. " 金币")
end