Spatial IO teleporter

local drive = 256
local chest = peripheral.find("ender_chest")
local spatialSide = "right"
local spatial = peripheral.wrap(spatialSide)
local chestPush = "east"
local chestOpose = "west"

local selected = 1
local destinations = {
    {name="Ardron's room",frequency=258,},
    {name="ME System",frequency=257,},
}

local this = {name="Deep Dark Miner",frequency=259,}

if fs.exists("event")==false then
       shell.run("pastebin get L7KYC10V event")
end
os.loadAPI("event")


function storePlayer()
    redstone.setOutput(spatialSide,true)
    sleep(0.1)
    redstone.setOutput(spatialSide,false)
    spatial.pushItem(chestOpose,2,1,1)
end

function loadPlayer()
    setDestination(drive)
    redstone.setOutput(spatialSide,true)
    sleep(0.1)
    redstone.setOutput(spatialSide,false)
    spatial.pushItem(chestOpose,2,1,1)
    setDestination(this.frequency)
end

function getCell(frequency)
    chest.setFrequency(frequency)
    chest.pushItem(chestPush,1,1,1)
end

function setDestination(frequency)
    chest.setFrequency(frequency)
end

function teleport(destination)
    getCell(drive)
    setDestination(destinations[destination].frequency)
    storePlayer()
    setDestination(this.frequency)
end

function receiveTeleport()
    getCell(this.frequency)
    loadPlayer()
end

function drawPositions()
    term.clear()
    for i,data  in ipairs(destinations) do
        term.setCursorPos(4,i)
        term.write(data.name)
    end
end

function drawSelection(old,new)
    term.setCursorPos(2,old)
    term.write(" ")
    term.setCursorPos(2,new)
    term.write(">")
end

function onkey(key)
    if key==200 then
        --up
        if selected>1 then
            selected = selected - 1
        end
        drawSelection(selected + 1, selected)
    elseif key==208 then
        --down
        if #destinations>selected then
            selected = selected +1
        end
        drawSelection(selected - 1, selected)
    elseif key==28 then
        --enter
        teleport(selected)
    end
end
event.addHandler("key",onkey)

function checkPendingTeleports()
    local item = chest.getStackInSlot(1)
    if item==nil then return end
    receiveTeleport()
end
event.addHandler("timer",checkPendingTeleports)

drawPositions()
drawSelection(1,1)
while true do
    event.handleCCEvents(0.5)
end