【进阶实战】邮件合并：同类奖励邮件的合并展示封装

local mergePool = {}
local MERGE_WINDOW = 86400
local MERGE_MAX = 10
local function queueReward(actorName, key, item, num)
    local now = os.time()
    local pool = mergePool[key]
    if pool == nil or now - pool.start > MERGE_WINDOW or pool.count >= MERGE_MAX then
        if pool and pool.count > 0 then
            flushReward(key)
        end
        mergePool[key] = { start = now, count = 0, item = item, num = 0 }
        pool = mergePool[key]
    end
    pool.count = pool.count + 1
    pool.num = pool.num + num
    if pool.count >= MERGE_MAX then
        flushReward(key)
    end
end

local function flushReward(key)
    local pool = mergePool[key]
    if pool == nil or pool.count == 0 then
        return
    end
    sendmail("#" .. key, 0, "活动奖励合并（" .. pool.count .. "次）",
        "累计获得 " .. pool.item .. " 乘 " .. pool.num .. "，请查收附件。",
        pool.item .. "," .. pool.num)
    mergePool[key] = nil
end