local cjson = require "cjson"
local redis = require "resty.redis"
local red = redis:new()  

-- 設定後續操作的超時（以毫秒為單位）保護，包括connect方法
red:set_timeout(60000) 
-- 連線redis;兩個引數分別是IP以及埠號
local ok, err = red:connect("xxx.xxx.xxx.xxx", 6379) 
if not ok then
    return
end
-- 設定連線密碼
red:auth("xxxx")
-- 切換資料庫，不設定，預設是0庫
red:select(1)

local json_results={}

local request_method = ngx.var.request_method
if request_method == "GET" then
    json_results["userTag"] = 0
    local value = cjson.encode(json_results)
    ngx.say(value) 
    return
elseif request_method == "POST" then
    ngx.req.read_body()
    args= ngx.req.get_body_data()
end

local arg=cjson.decode(args)

if (type(arg["userIdList"]) == "nil") or (arg["userIdList"] == "") then 
    json_results["userTag"] = 0
    local value = cjson.encode(json_results)
    ngx.say(value) 
    return
end

local useridList = {}
-- 設定為pipeline()模式；批量獲取value
red:init_pipeline()
for k,userid in pairs(arg["userIdList"]) do
    useridList[k] = userid
    red:get("taonewslabel_"..userid)
end
-- 提交所有的key
local respTable, err = red:commit_pipeline()  

-- local res, err = red:get(userid) 或者這種一次獲得一個key

if (not respTable) or  respTable == ngx.null then
    json_results["userTag"] = 0
    local value = cjson.encode(json_results)
    ngx.say(value) 
    return
end

local i = 0
local res_userid={}
-- 對有值的key的處理
for k, v in pairs(respTable) do  
     if v ~= ngx.null then 
        res_userid[#res_userid+1] = cjson.decode(v)
        table.remove(useridList,k-i)
        i = i + 1
     end
end 
-- 對無值的key的處理
for k,userid in pairs(useridList) do
    local k_v={}
    k_v["error_code"] = 101
    k_v["userid"] = userid
    res_userid[#res_userid+1] = k_v
end

json_results["userTag"] = res_userid
local value = cjson.encode(json_results)
ngx.say(value) 
red:close()