Mining Turtle

local args = {...}

local stripLength = 32

if not #args == 1 then
  print("Usage: smine <mines>")
  return
end

function strip()
  for i=1,stripLength do
    checkFuel()
    checkInv()
    while not turtle.forward() do turtle.dig() end
    while turtle.detectUp() do
      turtle.digUp()
      sleep(0.2)
    end
    while turtle.detectDown() do
      turtle.digDown()
      sleep(0.2)
    end

    if i%8 == 0 then
      turtle.select(16)
      while not turtle.forward() do turtle.dig() end
      while turtle.detectUp() do
        turtle.digUp()
        sleep(0.2)
      end
      if not turtle.back() then
        turtle.turnLeft()
        turtle.turnLeft()
        while not turtle.forward do turtle.dig() end
        turtle.turnLeft()
        turtle.turnLeft()
      end
      turtle.placeUp()
      turtle.select(1)
    end
  end

  turtle.turnLeft()
  turtle.turnLeft()

  for i=1,stripLength do
    while not turtle.forward() do turtle.dig() end
  end
end

function checkFuel()
  if turtle.getFuelLevel() <= 64 then
    print("Error: Low fuel")
    for i=1,14 do
      turtle.select(i)
      turtle.refuel()
    end
  end
end

function advance()
    print("Moving to next stripmine")
    for y=1,3 do
        turtle.dig() -- Digs first Block in front
        turtle.forward()
        turtle.digUp()
        turtle.up()
        turtle.digUp()
        turtle.down()
    end
end

function checkInv()
  isFull = true

  for i=1,14 do
    if turtle.getItemCount(i) == 0 then
      isFull = false
    end
  end

  if isFull == true then
    turtle.select(15)
    while not turtle.placeDown() do turtle.digDown() end
    for i=1,14 do
      turtle.select(i)
      turtle.dropDown()
    end
  end
end

print("Place torches in slot 16")
print("Place chest/s in slot 15 (will be automatically placed and filled when inventory is full)")

for x=1,args[1] do
  turtle.turnLeft()
  strip()
  strip()
  turtle.turnRight()
  advance()
end