time = 0.5
torch = 0
turn = 1
shell.run("clear")
args = {...}
length = tonumber(args[1])
chest = args[2]

if length == nil then
  print "How far?"
  length = tonumber(read())
  back = length
else
  back = length
end

if type(length) ~= "number" then
  error("Only Use Numbers!!")
end

function forward()
  while not turtle.forward() do
    turtle.attack()
    turtle.dig()
  end
end

function backward()
  while not turtle.back() do
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.attack()
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
  end
end

function dig()
   while turtle.detectUp() do
     turtle.digUp()
     sleep(time)
   end
   turtle.digDown()
end

function right()
  turtle.turnRight()
  while turtle.detect() do
    turtle.dig()
    sleep(time)
  end
  forward()
  dig()
  backward()
  turtle.turnLeft()
end

function left()
  turtle.turnLeft()
  while turtle.detect() do
    turtle.dig()
    sleep(time)
  end
  forward()
  dig()
  backward()
  if torch <= 0 then
    turtle.select(1)
    turtle.place()
    torch = 10
  end
  turtle.turnRight()
end

function turnAround()
  turtle.turnLeft()
  turtle.turnLeft()
end

function done()
  turtle.select(15)
  if not turtle.compareDown() then
    turtle.placeDown()
    turtle.select(1)
  end

  for i=1,16 do
    turtle.select(i)
    turtle.dropDown(64)
  end
  turtle.select(1)
end

while true do
  if turtle.getFuelLevel() < 3 then
    turtle.select(16)
    turtle.refuel(10)
    turtle.select(1)
  end
  if length > 0 then
    while turtle.detect() do
      turtle.dig()
      sleep(time)
    end
    forward()
    print("TOGO:" .. length)
    dig()
    right()
    left()
    torch = torch - 1
    length = length - 1
  else
    if back > 0 then
      if turn > 0 then
        turnAround()
        turn = 0
      end
      forward()
      back = back - 1
      print("BACK:" .. back)
    else
      if chest == "c" then
        done()
      end
      error("FINISHED")
    end
  end
end
--     wget http://play.smtgames.com/dl/dig.lua dig