--邮件管理
local LuaMongo = _G.lua_mongo
local Log = require("common.Log")
local DB = require("common.DB")
local Util = require("common.Util")
local Msg = require("core.Msg")
local ObjHuman = require("core.ObjHuman")
local RoleSystemLogic = require("roleSystem.RoleSystemLogic") 
local RoleSystemDefine = require("roleSystem.RoleSystemDefine") 
local RoleDBLogic = require("role.RoleDBLogic")
local MailExcel = require("excel.mail")
local CommonDB = require("common.CommonDB")

SYSTEM = 1 				-- 系统邮件
GONGGAO = 2 				-- 公告

MAIL_MAX_CNT = 100			-- 邮件最大值
MAIL_LOOKBACK_SEC = 90 * 86400	-- 查询回溯上限(覆盖较长 expireTime)
MAIL_SCAN_LIMIT = 2000		-- 单时间窗游标扫描上限
MAIL_SORT_DESC = {time = -1}	-- find 第4参: 按时间倒序，优先拿到最新邮件

local FIELD_ID = {_id = nil}
local FIELD_RECEIVER = {uuid = nil,type = nil}

--后面如果fbAccount有值应该把区服id一起
function add(type,receiverUuid,title,content,items,senderName,sender,time,fbTime,fbContent,fbAccount,expireTime) 
	if _G.is_middle == true or type == GONGGAO then
		return
	end
	
	local mail = {}
	mail.type = type
	mail.receiverUuid = receiverUuid
	mail.title = title
	mail.content = content
	mail.read = nil
	mail.senderName = title
    mail.head = 0
    mail.fbTime = fbTime
    mail.fbContent = fbContent
    
	--后面用到
    local fields = {head = 1,lv = 1}
    if fbAccount ~= nil then
        local db = RoleDBLogic.getDbByAccount(fbAccount,fields)
        mail.fbHead = db.head
        mail.fbLv = db.lv
	end
	
	if sender and sender.db and sender.db.identity then
		mail.identity = sender.db.identity
	end

	if sender and sender.db and sender.db.head then
		mail.head = sender.db.head
	end

    if time == nil then 
		mail.time = os.time()
    else
		mail.time = time
    end
	
    if expireTime then
        mail.expireTime = expireTime
    end	
	
	if items then
		mail.items = {}
		for _,item in ipairs(items) do 
			mail.items[#mail.items + 1] = {item[1],item[2]}
		end
	end
    if items == nil then
        mail.get = 1
        mail.flag = nil
    else
        mail.get = nil
        mail.flag = 1
    end
	LuaMongo.insert(DB.db_mail, mail)
	-- 检测红点会调用getMails(), 短时间插入多封邮件加上玩家邮件数量过多，会发生段错误
	-- RoleSystemLogic.onDotByUuid(receiverUuid, RoleSystemDefine.ROLE_SYS_ID_204)
	return mail

end

-- condition = {startLv = 1, endLv = 100, lastLoginTime = xxx}
local MailLvQuery = {lv = {["$gte"] = 0, ["$lte"] = 0}}
local MailLvField = {lastLoginTime = 1, lastLogoutTime = 1}
function sendMailByCondition(condition, title, content, gridList,fbTime,fbContent,fbAccount,expireTime)
	local startLv = condition.startLv and tonumber(condition.startLv)
	local endLv = condition.endLv and tonumber(condition.endLv)		
	local lastLoginTime = condition.lastLoginTime and tonumber(condition.lastLoginTime) or 0
	if startLv == nil or endLv == nil or lastLoginTime == nil then
		return 
	end
    
    local successCount = 0
    local failCount = 0

    --Log.write(Log.LOGID_ERR_PCALL, "mail sendMailByCondition" , "")
	-- 在线的只要等级符合直接发
	for uuid, oHuman in pairs(ObjHuman.onlineUuid) do
		if oHuman.db.lv >= startLv and 
			oHuman.db.lv <= endLv then
			p_ret, err = pcall(add, SYSTEM, oHuman.db._id, title, content, gridList, condition.senderName, nil, nil,fbTime,fbContent,fbAccount,expireTime)
			if p_ret then
				successCount = successCount + 1
                --Log.write(Log.LOGID_ERR_PCALL, "mail rolename=" .. oHuman.db.name, err)
			else 
				failCount = failCount + 1
				--Log.write(Log.LOGID_ERR_PCALL, "mail rolename=" .. oHuman.db.name, err)
			end					
		end 
	end

	-- 不在线的，还需要验证x天内登录
	MailLvQuery.lv["$gte"] = startLv
	MailLvQuery.lv["$lte"] = endLv
	LuaMongo.find(DB.db_char, MailLvQuery, MailLvField)
    while true do
        local data = {}
        if not LuaMongo.next(data) then
        	break
        end
        if not ObjHuman.onlineUuid[data._id] and 
        	(lastLoginTime == 0 or 
        		(data.lastLoginTime and data.lastLoginTime >= lastLoginTime) or
        		(data.lastLogoutTime and data.lastLogoutTime >= lastLoginTime)
        	) then
			p_ret, err = pcall(add, SYSTEM, data._id, title, content, gridList, condition.senderName, nil, nil,fbTime,fbContent,fbAccount)
			if p_ret then	
				successCount = successCount + 1
			else 
				failCount = failCount + 1
				Log.write(Log.LOGID_ERR_PCALL, "mail role uuid=" .. data._id, err)
			end	
        end
    end
    return successCount, failCount
end

function del(mailUuid)
	FIELD_ID._id = mailUuid
	LuaMongo.remove(DB.db_mail, FIELD_ID)
end

function getMail(mailUuid)
	FIELD_ID._id = mailUuid
	LuaMongo.find(DB.db_mail,FIELD_ID)
	local mail = {}
	if not LuaMongo.next(mail) then
		return nil
	end
	return mail
end

local function cmpMail(a, b)
	return a.time > b.time
end

local mails = {}
local seenMailIds = {}

local function isMailExpired(m, now)
	if type(m.time) ~= "number" then
		m.time = 0
	end
	local expireTime = m.expireTime
	if expireTime and type(expireTime) == "number" then
		return m.time <= now - expireTime
	end
	return m.time <= now - 7 * 86400
end

local function countValidThreshold(sortedMails, now)
	local cnt = 0
	for _, m in ipairs(sortedMails) do
		if not isMailExpired(m, now) then
			cnt = cnt + 1
			if cnt >= MAIL_MAX_CNT then
				return cnt, m.time
			end
		end
	end
	return cnt, nil
end

-- 缓存过大时只保留最新 MAIL_MAX_CNT 条未过期，降低内存与排序成本
local function trimTempMails(tempMails, now)
	if #tempMails <= MAIL_MAX_CNT * 2 then
		return
	end
	table.sort(tempMails, cmpMail)
	local writeIdx = 0
	for _, m in ipairs(tempMails) do
		if not isMailExpired(m, now) then
			writeIdx = writeIdx + 1
			tempMails[writeIdx] = m
			if writeIdx >= MAIL_MAX_CNT then
				break
			end
		end
	end
	for i = writeIdx + 1, #tempMails do
		tempMails[i] = nil
	end
end

local function buildMailQuery(receiverUuid, mailType, startTime, endTime, useLte)
	local query = {receiverUuid = receiverUuid}
	if mailType ~= nil then
		query.type = mailType
	end
	local timeCond = {["$gte"] = startTime}
	if useLte then
		timeCond["$lte"] = endTime
	else
		timeCond["$lt"] = endTime
	end
	query.time = timeCond
	return query
end

-- function getMails(receiverUuid,mailType)
-- 	for key in ipairs(mails) do 
-- 		mails[key] = nil
-- 	end

-- 	FIELD_RECEIVER.receiverUuid = receiverUuid
-- 	FIELD_RECEIVER.type = mailType

--     LuaMongo.find(DB.db_mail,{["$query"]=FIELD_RECEIVER})
    
-- 	local lastTime = os.time() - 7 * 86400
--     local mailCnt = 0
-- 	while true do
-- 		local mail = {}
-- 		-- if not LuaMongo.next(mail) then
-- 		-- 	break
-- 		-- end

-- 		local res, err = pcall(function ()
-- 			return LuaMongo.next(mail)
-- 		end)

-- 		if not res then
-- 			Log.write(Log.LOGID_DEBUG, "MailManager.getMails err = ".. err)
-- 			break
-- 		end

-- 		if not err then
-- 			break
-- 		end

--        if mail.expireTime then  -- 有指定过期时间
--             if mail.time > os.time() - mail.expireTime then
-- 			    mailCnt = mailCnt + 1
-- 			    mails[mailCnt] = mail
--             end
--        elseif mail.time > lastTime then -- 没有就用默认过期时间
--             mailCnt = mailCnt + 1
-- 			mails[mailCnt] = mail
--        end
-- 	end
    
--     if mailCnt > MAIL_MAX_CNT then
-- 		table.sort(mails, cmpMail)
-- 		for i = MAIL_MAX_CNT + 1, mailCnt do
-- 			mails[i] = nil
-- 		end
-- 	end    
-- 	return mails
-- end

-- 分段 + 倒序游标：兼顾 C 驱动稳定性与“取最新 100 封未过期”语义
function getMails(receiverUuid, mailType)
	for i = 1, #mails do
		mails[i] = nil
	end
	for k in pairs(seenMailIds) do
		seenMailIds[k] = nil
	end

	local now = os.time()
	local mailCnt = 0
	local tempMails = {}
	local thresholdTime = nil
	local lookbackStart = now - MAIL_LOOKBACK_SEC

	-- 半开区间 [start, end)；首窗含 now 用 lte
	local timeWindows = {
		{now - 7 * 86400,   now, true},
		{now - 14 * 86400,  now - 7 * 86400, false},
		{now - 30 * 86400,  now - 14 * 86400, false},
		{now - 60 * 86400,  now - 30 * 86400, false},
		{now - MAIL_LOOKBACK_SEC, now - 60 * 86400, false},
	}
	local serverOpenTime = CommonDB.getServerOpenTime()
	if serverOpenTime < lookbackStart then
		timeWindows[#timeWindows + 1] = {serverOpenTime, lookbackStart, false}
	end

	for _, window in ipairs(timeWindows) do
		local startTime, endTime, useLte = window[1], window[2], window[3]
		if startTime >= endTime then
			goto continue_window
		end

		if thresholdTime then
			local windowMaxTime = useLte and endTime or (endTime - 1)
			if windowMaxTime < thresholdTime then
				break
			end
		end

		local query = buildMailQuery(receiverUuid, mailType, startTime, endTime, useLte)
		LuaMongo.find(DB.db_mail, query, nil, MAIL_SORT_DESC)

		local mail = {}
		local scanCnt = 0
		while true do
			local ok, hasNext = pcall(function()
				return LuaMongo.next(mail)
			end)
			if not ok then
				Log.write(Log.LOGID_DEBUG, "MailManager.getMails next err: " .. tostring(hasNext))
				break
			end
			if not hasNext then
				break
			end

			scanCnt = scanCnt + 1
			if scanCnt > MAIL_SCAN_LIMIT then
				Log.write(Log.LOGID_DEBUG, string.format(
					"Mail segment limit hit! uuid=%s window=%d~%d",
					receiverUuid, startTime, endTime))
				break
			end

			if thresholdTime and type(mail.time) == "number" and mail.time < thresholdTime then
				break
			end

			local mailId = mail._id
			if not mailId or not seenMailIds[mailId] then
				if mailId then
					seenMailIds[mailId] = true
				end
				local m = {}
				for k, v in pairs(mail) do
					m[k] = v
				end
				tempMails[#tempMails + 1] = m
				trimTempMails(tempMails, now)
				local validCnt, th = countValidThreshold(tempMails, now)
				if th then
					thresholdTime = th
				end
			end

			for k in pairs(mail) do
				mail[k] = nil
			end
		end

		::continue_window::
	end

	table.sort(tempMails, cmpMail)
	for _, m in ipairs(tempMails) do
		if not isMailExpired(m, now) then
			mailCnt = mailCnt + 1
			mails[mailCnt] = m
			if mailCnt >= MAIL_MAX_CNT then
				break
			end
		end
	end

	return mails
end




function saveMail(mail)
    FIELD_ID._id = mail._id
    LuaMongo.update(DB.db_mail, FIELD_ID, mail)
end

function delAll(uuid,mailType)
    local QueryMailByUuid = {get = {["$exists"] = 0},  read = {["$exists"] = 1}}
    QueryMailByUuid.receiverUuid = uuid
    QueryMailByUuid.type = mailType
    QueryMailByUuid.get["$exists"] = 1
	LuaMongo.remove(DB.db_mail, QueryMailByUuid)
end