【数据存储】求购行：求购单的触发核验与撮合存储

---beforeaddqiugou: 求购上架前触发
---actor:玩家对象 itemName:求购物品 needNum:数量 price:总价
function beforeaddqiugou(actor, itemName, itemIdx,
    needNum, price)
    -- 等级门槛：50 级才能发布求购
    if getbaseinfo(actor, 6) < 50 then
        messagebox(actor, "角色等级小于 50 级，无法发起求购")
        return false
    end
    -- 单价的合理性：不低于市场指导价的一半
    local ref = Market.refPrice(itemName)
    if price < ref * needNum * 0.5 then
        messagebox(actor, "求购价过低，请参考市场价")
        return false
    end
    return true
end

---addqiugou: 求购上架成功触发
function addqiugou(actor, itemName, itemIdx,
    needNum, price)
    local player = class(actor)
    if not player then return end
    QiuGou.record(actor, itemName, needNum, price)
    sendmsg(actor, 1, "求购已挂出：" .. itemName ..
        " x" .. needNum)
end

---beforesellqiugou: 出售前触发，核验卖家的货
function beforesellqiugou(actor, itemName, itemIdx,
    needNum, price)
    -- 出售者的货物必须是未绑定状态
    if checkitemstate(Sell.itemOf(actor, itemIdx), 1) == 1 then
        messagebox(actor, "绑定的物品无法出售给求购单")
        return false
    end
    return true
end