module(...,package.seeall)
require("xap")
require("xap.bsc")
require("socket")
local class = require("pl.class").class

info={
   version="1.0", description="MODBUS"
}

-- This is class is OVER simplified for explanation purposes.
-- It might be we need to open/close the socket each time.
class.Modbus()
function Modbus:_init(ip, port)
        self.udp = socket.udp()
        self.udp:setsockname(ip, port)
end

function Modbus:set(state)
        self.udp:send(state)
end

function Modbus:get()
        return self.udp:receivefrom()
end


-- Reach out to modbus endpoint and grab state, compare to current xap endpoint value.
function pollModbus(t, e)
        local currentState = e.modbus:get()
        if currentState ~= e.state then
           e:setState(currentState)
           e:sendEvent()
        end
end

-- Handling xAPBSC.cmd message to control modbus action
function modCmd(e)
        e.modbus:set(e.state)
end

function init()
        local e = bsc.Endpoint{name="dbzoo.livebox.modbus:x.1",
                               direction=bsc.OUTPUT,
                               type=bsc.BINARY,
                               cmdCB=modCmd,
                               modbus=Modbus("1.2.3.4","3001")
                              }
        xap.Timer(pollModbus, 1, e):start()
end