local modem = peripheral.find("modem", rednet.open);

local logging = "Potion_Brewer_LOGGER"

local errorName = "DISPENSER_CONTROLLER"

-- different protocols used by this program
local dispenserRequestProtocol = "Potion_Brewer_Dispenser_Request_v001"
local dispenserNodeProtocol = "Potion_Brewer_Ingredient_Dispenser_Node_v001"
local beltSelectorProtocol = "Potion_Brewer_BELT_SELECTOR"
local scannerProtocol = "Potion_Brewer_SCANNER"

local timeoutErrorProtocol = "Potion_Brewer_ERROR_PROTOCOL_TIMEOUT"

-- different event names used by this program (lets just use protocols in future)
local eventDispenseItem = "EVENT_DISPENSE_"
local eventDispenseItemStarted = "EVENT_DISPENSE_STARTED_"
local eventSelectBelt = "EVENT_BELT_SELECT_"
local eventScanner = "EVENT_SCANNER_"

local scannerDispenser = "dispenser"

local timeoutTime = 10

local error = false

function log(string)
    print(string)
    rednet.broadcast("[" .. errorName .. "] " ..string, logging)
end

function dispenseItem(string)

    parallel.waitForAny(
    function()
        log("attempting to dispense " .. string)

        -- requrest that the item is dispensed
        rednet.broadcast(eventDispenseItem .. string, dispenserNodeProtocol)
        local message = ""
        local senderID = 0

        log("dispense request sent to nodes")

        -- wait for the response from the dispenser node
        while message ~= eventDispenseItemStarted .. string do
            senderID, message = rednet.receive(dispenserNodeProtocol)
        end

        log("response received")

        message = ""
        -- wait for the item to be detected on the conveyor
        while message ~= eventScanner .. scannerDispenser do
            senderID, message = rednet.receive(scannerProtocol)
        end

        log("item detected! dispense successful!")
    end,
    function()
        -- wait for timeout
        sleep(timeoutTime)
        log("Dispense Item Timeout! Took longer than " .. timeoutTime .. " seconds!")
        rednet.broadcast(errorName, timeoutErrorProtocol)
        error = true
    end)

end

dispenseItem("netherwart")