UwU

turningRight = true             -- If the first direction the turtle needs to turn is right, leave this true. Change to false if you need to turn left first.
blocksBetweenLanterns = 15 -- Number of blocks between placing torches

blocksSinceLastLantern = 0
while true do

  -- Place a block below and 2 blocks above
  turtle.placeDown()
  turtle.up()
  turtle.placeUp()
  turtle.down()

  -- Figure out if we need to place a lantern
  blocksSinceLastLantern = blocksSinceLastLantern + 1
  if blocksSinceLastLantern > blocksBetweenLanterns then
        if turtle.getItemCount(9) == 0 then
          print("Out of Lanterns")
          print("Place some in slot 9")
          print("and press ENTER to continue")
          read()
        end
        turtle.turnRight()
        turtle.turnRight()
        turtle.select(9)
        turtle.place()
        turtle.select(1)
        turtle.turnRight()
        turtle.turnRight()
        blocksSinceLastLantern = 0
  end

  -- If we can't move forward, start the process of moving unto the next row
  if turtle.forward() == false then

        -- Check which direction we need to turn
        if turningRight == true then

          -- Turn Right
          turtle.turnRight()
          if turtle.forward() == false then
                clearToContinue = false
                while clearToContinue == false do
                  turtle.turnRight()
                  turtle.forward()
                  turtle.turnLeft()
                  if turtle.forward() == true then
                        clearToContinue = true
                  end
                end
          end
          turtle.turnLeft()
          turningRight = false
        else

          -- Turn Left
          turtle.turnLeft()
          if turtle.forward() == false then
                clearToContinue = false
                while clearToContinue == false do
                  turtle.turnLeft()
                  turtle.forward()
                  turtle.turnRight()
                  if turtle.forward() == true then
                        clearToContinue = true
                  end
                end
          end
          turtle.turnRight()
          turningRight = true
        end

        -- Move forward until we hit the wall of the new row
        while turtle.detect() == false do
          turtle.forward()
        end

        -- Turn around
        turtle.turnRight()
        turtle.turnRight()

  end

  -- Check to make sure the inventory has materials
  inventoryEmpty = true
  for i=1,9 do
        if turtle.getItemCount(i) > 0 then
          inventoryEmpty = false
          break
        end
  end

  -- Pause if we ran out of stuff
  if inventoryEmpty == true then
        print("Need More Blocks!")
        print("Press Enter To Continue...")
        read()
  end

end