Monitor Displayer

--[[
Instructions:
> label set [Displayer Name]
> pastebin get J6Ss7FZd [Program Name]
> [Program Name]
--]]

local display_data = {}

function split(inputstr, sep)
  if sep == nil then
    sep = "%s"
  end
  local t={}
  for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
    table.insert(t, str)
  end
  return t
end

function updateData(msg)
  local category = msg
  local lines = split(msg, "\n")
  if #lines > 1 then
    display_data[lines[1]] = {unpack(lines, 2, #lines)}
  else
    display_data[lines[1]] = {}
  end
end

function getAbsolutePosition(screen_width, screen_height, pane_width, line_number)
  local x = 1
  screen_height = screen_height - 1
  while line_number > screen_height do
    line_number = line_number - screen_height
    x = x + pane_width
  end
  if x + pane_width * 2 > screen_width + 1 then
    return x, line_number + 1, screen_width - x + 1
  else
    return x, line_number + 1, pane_width
  end
end

function displayTitle(m, screen_width, str)
  m.setCursorPos(1, 1)
  m.setBackgroundColor(colors.yellow)
  m.setTextColor(colors.black)
  m.write(str..string.rep(" ", screen_width - string.len(str)))
end

function displayLabel(m, x, y, length, str)
  length = length - 1
  m.setCursorPos(x, y)
  m.setBackgroundColor(colors.purple)
  m.setTextColor(colors.white)
  m.write(str..string.rep(" ", length - string.len(str)))
end

function displayItem(m, x, y, length, leftstr, rightstr, percent)
  leftstr = split(leftstr, ":")[2]
  length = length - 1
  local hlcolor = colors.lime
  if percent < 0.2 then
    hlcolor = colors.red
  elseif percent < 0.5 then
    hlcolor  = colors.orange
  end
  hl_len = math.floor(length * percent)
  remain_len = length - string.len(leftstr) - string.len(rightstr)
  local str
  if remain_len > 0 then
    str = leftstr..string.rep(" ", remain_len)..rightstr
  else
    str = string.sub(leftstr, 1, string.len(leftstr) + remain_len - 3)..".. "..rightstr
  end
  m.setCursorPos(x, y)
  m.setBackgroundColor(hlcolor)
  m.setTextColor(colors.white)
  m.write(string.sub(str, 1, hl_len))
  m.setCursorPos(x + hl_len, y)
  m.setBackgroundColor(colors.gray)
  m.setTextColor(colors.white)
  m.write(string.sub(str, hl_len + 1, string.len(str)))
end

function displayAll(m, title)
  m.setTextScale(1)
  m.setBackgroundColor(colors.gray)
  m.clear()
  local screen_width, screen_height = m.getSize()
  local pane_width = screen_width / math.floor(screen_width / 30)
  local item_width = pane_width / 2
  local line_number = 1
  displayTitle(m, screen_width, title)
  for category, items in pairs(display_data) do
    local x, y, width = getAbsolutePosition(screen_width, screen_height, pane_width, line_number)
    displayLabel(m, x, y, width, category)
    for i, item in pairs(items) do
      content = split(item, " ")
      if content[3] ~= 0 then
        if (i % 2 == 1) then
          line_number = line_number + 1
          x, y, width = getAbsolutePosition(screen_width, screen_height, pane_width, line_number)
          item_width = math.floor(width / 2)
          displayItem(m, x, y, item_width, content[1], content[2], content[2] / content[3])
        end

        if (i % 2 == 0) then
          item_width = math.floor(width / 2)
          displayItem(m, x + item_width, y, width - item_width, content[1], content[2], content[2] / content[3])
        end
      end

    end
    line_number = line_number + 1
  end
end

function main()
  local monitor = peripheral.find("monitor")
  monitor.setTextScale(0.5)
  peripheral.find("modem", rednet.open)
  local id, msg
  while true do
    while not rednet.isOpen() do
      os.sleep(10)
      peripheral.find("modem", rednet.open)
    end
    id, msg = rednet.receive("ITEM_UPDATE")
    updateData(msg)
    displayAll(monitor, os.getComputerLabel())
  end
end

main()