[AT_switch] server

------ PARAMS ------
MODEM_SIDE='bottom'
ENGINE_SIDE='top'
CHECK_PERIOD = 5 -- (seconds)
------ END PARAMS --

timerId = nil
remainToCheck = 0
processing = false

function mainScreen(isProcessing)
    if(not isProcessing) then
        term.setBackgroundColor(colors.lime)
        term.setCursorPos(18, 6)
        term.write("                  ")
        term.setCursorPos(18, 7)
        term.write(" Initiate process ")
        term.setCursorPos(18, 8)
        term.write("                  ")
    else
        term.setBackgroundColor(colors.gray)
        term.setCursorPos(18, 6)
        term.write("                  ")
        term.setCursorPos(18, 7)
        term.write("   Processing...  ")
        term.setCursorPos(18, 8)
        term.write("                  ")
    end
end

function main()
    rednet.open(MODEM_SIDE)
    checkers = { rednet.lookup('switch_check','checker') }
    remainToCheck = #checkers

    term.clear()
    mainScreen(false)

    timerId = os.startTimer(CHECK_PERIOD)

    while true do
        data = { os.pullEvent() }
        evt = data[1]
        if(evt == 'rednet_message') then
            mess = data[3]
            if(mess.type == 'status' and mess.status == false) then
                remainToCheck = remainToCheck - 1
                if(remainToCheck == 0) then
                    processing = false
                    mainScreen(false)
                    redstone.setOutput(ENGINE_SIDE, false)
                end
            end

        elseif(evt == 'timer' and data[2] == timerId) then
            if(processing) then
                remainToCheck = #checkers
                for _,checker in pairs(checkers) do
                    rednet.send(checker, {type = 'check'})
                end
                timerId = os.startTimer(CHECK_PERIOD)
            end
        elseif(evt == 'mouse_click' and processing == false) then
            x = data[3]
            y = data[4]
            if(x >= 18 and x <= 36 and y >= 6 and y <= 8) then
                mainScreen(true)
                redstone.setOutput(ENGINE_SIDE, true)
                processing = true
                timerId = os.startTimer(CHECK_PERIOD)
            end
        end
    end
end
main()