Turtle Tunnel

local args = { ... }
local distance = 0
local dropItems = false
local makeFloor = false
local enclosed = false
local height = 2
turtle.select(1)

function select(slot)
  turtle.select(slot)
end

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

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

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

function place(slot)
  select(slot)
  while not turtle.place() do
    turtle.dig()
  end
end

function placeUp(slot)
  select(slot)
  while not turtle.placeUp() do
    turtle.digUp()
  end
end

function placeDown(slot)
  select(slot)
  while not turtle.placeDown() do
    turtle.digDown()
  end
end

function left()
  turtle.turnLeft()
end

function right()
  turtle.turnRight()
end

function uturn()
  left()
  left()
end

function flooring(slot)
  for i = 2, distance do
    turtle.digUp()
    placeDown(slot)
    forward()
  end
  turtle.digUp()
  placeDown(slot)
end

function roofingCorner(slot)
  for i = 2, distance do
    placeDown(slot)
    forward()
  end
  placeDown(slot)
end

function roofing(slot)
  for i = 2, distance do
    placeUp(slot)
    forward()
  end
  placeUp(slot)
end


-- parse command line
if #args == 0 then
  print("Usage: Tunnel [distance]")
  print("Optional tags:")
  print(" -hx: height of tunnel x (1-3)")
  print("       (default: 2)")
  print(" -d: drop items")
  print(" -f: create floor")
  print("      (put mats in slot 1)")
  print(" -e: enclosed")
else
  distance = args[1]
  if #args > 1 then
    for i=2, #args do
      if args[i] == "-d" then
        dropItems = true
      elseif args[i] == "-f" then
        turtle.select(1)
        makeFloor = true
      elseif string.sub(args[i], 1, 2) == "-h" then
        height = tonumber(string.sub(args[i], 3, 3))
      elseif args[i] == "-e" then
        enclosed = true
      end
    end
  end
end

if enclosed then --do enclosed tunnel
  flooring(14)
  left()
  forward()
  left()
  flooring(13)
  left()
  forward()
  forward()
  left()
  flooring(15)
  up()
  uturn()
  flooring(11)
  right()
  forward()
  forward()
  right()
  flooring(9)
  up()
  uturn()
  flooring(5)
  left()
  forward()
  forward()
  left()
  flooring(7)
  up()
  uturn()
  roofingCorner(3)
  right()
  forward()
  forward()
  right()
  roofingCorner(1)
  right()
  forward()
  right()
  down()
  down()
  roofing(2)
  down()
  uturn()
else --do regular tunnel
  for i = 1, distance do
    forward()
    if height > 1 then turtle.digUp() end
    if height > 2 then turtle.digDown() end
    if makeFloor then
      placeDown()
    end
    if dropItems then turtle.drop() end
  end
end