local sys = require "sys"
local socket = require "socket"

local event = {}
local eventList = {}

local function guid()
    local seed={'e','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'}
    local tb={}
	math.randomseed(math.floor(os.time() * math.random()))
    for i = 1, 32 do
        table.insert(tb, seed[math.random(1,16)])
    end
    local sid=table.concat(tb)
    return string.format('%s-%s-%s-%s-%s',
        string.sub(sid, 1, 8),
        string.sub(sid, 9, 12),
        string.sub(sid, 13, 16),
        string.sub(sid, 17, 20),
        string.sub(sid, 21, 32)
    )
end

function event.publish(id, msg)
	if eventList[id] ~= nil then
		for _, v in pairs(eventList[id]) do
			if(type(v) == "table") then
				v.callback(msg)
			end
		end
	end
end

function event.wait(id, timeout)
	if eventList[id] == nil then
		eventList[id] = {}
	end
	local result = false
	local message
	local obj = {}
	obj.timeout = timeout
	obj.callback = function(msg)
		result = true
		message = msg
	end

	local guid = guid()
	eventList[id][guid] = obj

	local tickstart = math.floor(socket.gettime() * 1000)

	while math.floor(socket.gettime() * 1000) - tickstart < timeout do
		if result == true then
			eventList[id][guid] = nil
			return result, message
		end
		sys.wait(1)
	end

	eventList[id][guid] = nil

	return result
end

return event