【网络通信】私聊消息：点对点投递与离线转邮件

---私聊的发送：在线直投与离线转投
function Chat.private(actor, toName, text)
    local player = class(actor)
    if not player then return false end
    local target = getplayerbyname(toName)
    if not target then return false end
    -- 黑名单的拦截
    if Friend.blacklisted(toName, actor) then
        sendmsg(actor, 1, "消息无法送达")
        return false
    end
    -- 频控：每分钟最多 20 条
    if not Chat.freqOk(actor, 20, 60) then
        sendmsg(actor, 1, "发送过于频繁")
        return false
    end
    sendmsg(target, 1, "[私聊] " .. actor .. "：" .. text)
    Chat.storeOffline(actor, toName, text)
    return true
end

---离线的转投：消息转邮件到达
setontimerex(99, 60)
function Chat.offlineFlush()
    for uid, box in pairs(Chat.offlineBox) do
        if #box > 0 and Online.isOnline(uid) then
            sendmsg(uid, 1, "有 " .. #box ..
                " 条离线私聊，点击查看")
            -- 上线后的首屏拉取离线消息
            Chat.deliverPending(uid, box)
            Chat.offlineBox[uid] = nil
        elseif #box > 50 then
            -- 离线积压超 50 条转邮件摘要
            sendmail(uid, 8010, "离线消息摘要",
                table.concat(box, "\n"), "")
            Chat.offlineBox[uid] = nil
        end
    end
end