--[[
- @desc   用于调试  lua数据输出
- @param  string   字符串 
- return  string
--]]
function dump(v)
    if not __dump then
    	function __dump(v, t, p)    
			local k = p or "";

			if type(v) ~= "table" then
				table.insert(t, k .. " : " .. tostring(v));
			else
				for key, value in pairs(v) do
					__dump(value, t, k .. "[" .. key .. "]");
				end
			end
		end
	end 
	local t = {'======== Lib:Dump Content ========'};
	__dump(v, t);
	print(table.concat(t, "\n"));
end


local server = require "resty.websocket.server"
local redis = require "resty.redis" 
local cjson = require "cjson"

local function exit()
	--获取URL参数
	local _GET = ngx.req.get_uri_args() 
    ngx.log(ngx.ERR, "用户" .. _GET['rnd'] .." 离开了房间  : ", err)
    --if is_ws == nil then ngx.eof() end 
    ngx.flush(true)
    ngx.exit(ngx.HTTP_OK)
    return nil
end

local ok, err = ngx.on_abort(exit) --注册一个函数  当客户端断开连接时执行
if err then
    return exit()
end

--获取聊天室id 
local channel_id = 800 
local channel_name = "chat_" .. tostring(channel_id)

--create connection
local wb, err = server:new{
	timeout = 5000,
	max_payload_len = 65535
}
 
if not wb then
   ngx.log(ngx.ERR, "failed to new websocket: ", err)
   return exit()
end
 
 
----创建redis实例
local getRedis = function (key)
    if not key then 
      return nil
    end
     
    if ngx.ctx[key] then
      return ngx.ctx[key]
    end
    
    --dump('-------------创建redis实例---------------------')
	local red = redis:new()
	--red:set_timeout(5000) -- 1 sec 设置连接超时1秒
	local  ok, err = red:connect("127.0.0.1", 6379) 
	 if not ok then 
	    ngx.log(ngx.ERR, "failed to connect redis: ", err)
	end 
	ngx.ctx[key] = red
	return red 
end


local pub = function()
   local red = getRedis('redisfn1') 
    --redis 订阅 
    local res, err = red:subscribe(channel_name)
    if not res then
        ngx.log(ngx.ERR, "failed to sub redis: ", err)
        wb:send_close()
        return  exit() 
    end

    -- 不断读取数据如果有值立刻发送给客户端
    while true do
        local res, err = red:read_reply()  
        
        if res then 
            local bytes, err = wb:send_text(cjson.encode(res))
            if not bytes then
                wb:send_close() 
                ngx.log(ngx.ERR, "failed to send text: ", err)
                return exit()
            end
        end
        ngx.sleep(0.5)
    end
end 
 
local co = ngx.thread.spawn(pub)
 
 

--main loop 
while true do
    -- 获取数据
    local data, typ, err = wb:recv_frame() 
    -- 如果连接损坏 退出
    if wb.fatal then
        ngx.log(ngx.ERR, "failed to receive frame: ", err)
        return exit()
    end

    if not data then 
    
        local bytes, err = wb:send_ping()
        if not bytes then
          ngx.log(ngx.ERR, "failed to send ping: ", err)
          return exit()
        end 
        
    elseif typ == "close" then
    
        break
        
    elseif typ == "ping" then
    
        local bytes, err = wb:send_pong()
        if not bytes then
            ngx.log(ngx.ERR, "failed to send pong: ", err)
            return exit()
        end
        
    elseif typ == "pong" then
    
        --ngx.log(ngx.ERR, "client ponged")
        
    elseif typ == "text" then 
    
        --接收消息写入redis 
		local red = getRedis('redisfn2') 
        local res, err = red:publish(channel_name, data)
        if not res then
            ngx.log(ngx.ERR, " 接收消息写入redis错误 failed to publish redis: ", err)
        end 
    
    else    
	    break
	end
     ngx.sleep(0.5)
end

getRedis('redisfn1'):set_keepalive(10000, 100)
getRedis('redisfn2'):set_keepalive(10000, 100)
wb:send_close()
ngx.thread.wait(co)