forge

cGrind = peripheral.wrap("left")
cSmelt = peripheral.wrap("chest_0")
cOutput = peripheral.wrap("right")

blocks = {}
size = cGrind.getInventorySize()

for i = 1, size, 1 do
  slot = cGrind.getStackInSlot(i)
  if slot then
    -- print(slot.display_name.." ..... " .. slot.qty)
    s = {name=slot.display_name, qty=slot.qty}
    table.insert(blocks, s)
  end

end

pos = 1

function handleKey(key)
  if key == keys.up and pos > 0 then
    pos = pos - 1
  elseif key == keys.down and pos < table.getn(blocks) then
    pos = pos + 1
  elseif key == keys.right then
    smelt()
  elseif key == keys.q then
    return nil
  end
end

function draw(t, pos)
  term.clear()
  term.setCursorPos(4,4)
  for k,v in pairs(t) do
    term.write(v.name .. " ............. " ..v.qty)
  end

  for i = 4, table.getn(t)+4, 1 do
    term.setCursorPos(2,i)
    if pos == i then
      term.write(">")
    end
  end
end

while true do

  draw(blocks, pos)

  if pos == nil then break end

  evt, key = os.pullEvent("key")
  pos = handleKey(key)
end