Drop Wool

colors = {"white", "orange", "magenta", "light_blue", "yellow", "lime", "pink", "gray", "light_gray", "cyan", "purple", "blue", "brown", "green", "red", "black"}
currentColor = 1
colorMap = {}
waitTime = 0

function UpdateLog()
  file = fs.open("log", "w")
  file.writeLine(currentColor)
  for i = 1, 16, 1 do
    if colorMap[i] == nil then
      file.writeLine()
    else
      file.writeLine(colorMap[i])
    end
  end
  file.close()
end

function ReadFile()
  if arg[2] ~= nil then
    currentColor = tonumber(arg[1])
    UpdateLog()
  else
    file = fs.open("log", "r")
    if file == nil then
      UpdateLog()
    else
      currentColor = tonumber(file.readLine())
      for i = 1, 16, 1 do
        x = file.readLine()
        if x ~= nil and x ~= "" then
          colorMap[i] = tonumber(x)
        end
      end
      file.close()
    end
  end
end

function CheckColor(color)
  item = turtle.getItemDetail()
  if item ~= nil and item.name == "minecraft:"..colors[color].."_wool" then
    return true
  end
  return false
end

function FindColor(color)
  if CheckColor(color) then
    return true
  end

  if colorMap[color] ~= nil then
    turtle.select(colorMap[color])
    if CheckColor(color) then
      return true
    end
  end

  for i = 1, 16, 1 do
    turtle.select(i)
    if CheckColor(color) then
      colorMap[color] = i
      return true
    end
  end

  return false
end

if arg[1] ~= nil then
  waitTime = tonumber(arg[1])
end
ReadFile()
while FindColor(currentColor) do
  turtle.dropDown(1)
  currentColor = currentColor + 1
  if currentColor > 16 then
    currentColor = 1
  end
  UpdateLog()
  if waitTime > 0 then
    sleep(waitTime)
  end
end

print("Need more "..colors[currentColor].." wool")