【后端接口】师门商店：贡献兑换的接口与限购

local SHOP = {
    [1] = { item = "金创药",       cnt = 5, cost = 20,  cap = 5 },
    [2] = { item = "强化石",       cnt = 1, cost = 120, cap = 2 },
    [3] = { item = "烈火剑法残页", cnt = 1, cost = 500, cap = 1 },
}
function redeem(actor, goodsId)
    local goods = SHOP[goodsId]
    if goods == nil then
        sendmsg(actor, 0, "师门商店没有这件商品")
        return
    end
    local week = os.date("%W")
    local key = "SM_BUY_" .. goodsId .. "_" .. week
    local bought = tonumber(getplayvar(actor, "HUMAN", key) or "0")
    if bought >= goods.cap then
        sendmsg(actor, 0, "本周限购已经用完，下周再来")
        return
    end
    local pt = tonumber(getplayvar(actor, "HUMAN", "SHIMEN_PT") or "0")
    if pt < goods.cost then
        sendmsg(actor, 0, "师门贡献不足，还差 " .. (goods.cost - pt) .. " 点")
        return
    end
    setplayvar(actor, "HUMAN", "SHIMEN_PT", pt - goods.cost, 1)
    setplayvar(actor, "HUMAN", key, bought + 1, 1)
    giveitem(actor, goods.item, goods.cnt)
    sendmsg(actor, 0, "兑换成功，获得 " .. goods.item .. " x" .. goods.cnt)
end

local function addPt(actor, n)
    local day = os.date("%Y%m%d")
    local today = tonumber(getplayvar(actor, "HUMAN", "SM_PT_" .. day) or "0")
    if today >= 200 then
        sendmsg(actor, 0, "今日贡献已达上限 200 点")
        return
    end
    setplayvar(actor, "HUMAN", "SM_PT_" .. day, today + n, 1)
    local total = tonumber(getplayvar(actor, "HUMAN", "SHIMEN_PT") or "0") + n
    setplayvar(actor, "HUMAN", "SHIMEN_PT", total, 1)
end