Build Stairs

function checkFuel()
  if ( turtle.getFuelLevel() < 10 ) then
    print("Fuel Level is less than 10, please place fuel in slot 1")
    while ( turtle.getFuelLevel() < 10 ) do
      if ( turtle.getItemCount(1) > 0 ) then
        turtle.refuel()
      end
      sleep(1)
    end
    print("Turtle Refuled, Fuel Level = " .. turtle.getFuelLevel())
  end
end

function invFull()
  full=true
  for i=1,16 do
    if ( turtle.getItemCount(i) == 0 ) then
      full=false
    end
  end
  return full
end

function placeTorch()
  turtle.turnRight()
  moveForward()
  turtle.turnRight()
  if ( not hasTorches() ) then
    print("No More Torches, Please replenish")
    while ( not hasTorches() ) do
      sleep(1)
    end
  end
  turtle.select(16)
  turtle.place()
  turtle.select(1)
  turtle.turnRight()
  moveForward()
  turtle.turnRight()
end

function hasTorches()
  if ( turtle.getItemCount(16) > 0 ) then
    return true
  else
    return false
  end
end

function checkInv()
  if ( invFull() ) then
    print("Inventory Full, Please Empty")
    while ( invFull() ) do
      sleep(1)
    end
  end
end

function moveUp()
  while ( not turtle.up() ) do
    turtle.digUp()
    checkInv()
  end
end

function moveDown()
  while ( not turtle.down() ) do
    turtle.digDown()
    checkInv()
  end
end

function moveForward()
  while ( not turtle.forward() ) do
    turtle.dig()
    checkInv()
  end
end

function digForward()
  while ( turtle.detect() ) do
    turtle.dig()
    checkInv()
  end
end

function rotate()
  for i=1,2 do
    turtle.turnLeft()
  end
end

function digLevel()
  turtle.turnLeft()
  digForward()
  rotate()
  digForward()
  turtle.turnLeft()
end


args={ ... }
stairDepth=tonumber(args[1])
checkFuel()
moveForward()
for i=1,stairDepth/2 do
  digLevel()
  for j=1,4 do
    moveUp()
    digLevel()
    checkFuel()
  end
  moveDown()
  moveForward()
  digLevel()
  if ( i%2 == 1 ) then
    placeTorch()
  end
  for j=1,4 do
    moveDown()
    digLevel()
    checkFuel()
  end
  moveForward()
  moveDown()
end