repeatDig

local args = { ... }

numArgs = table.getn(args)

TORCH_INTERVAL = 5

function fuel ()
  if turtle.getFuelLevel() == 0 then
    turtle.select(1)
    turtle.refuel(1)
  end
end

function plantTunnelTorch ()
  turtle.select(2)
  turtle.placeDown()
end

function goodDig ()
  while turtle.detect() do
    fuel()
    turtle.dig()
    sleep(0.5)
  end
  fuel()
end

function goodDigUp ()
  while turtle.detectUp() do
    fuel()
    turtle.digUp()
    sleep(0.5)
  end
  fuel()
end

function threeByThree ()
  goodDigUp()
  turtle.digDown()
  fuel()
  turtle.turnLeft()
  goodDig()
  turtle.forward()
  goodDigUp()
  turtle.digDown()
  fuel()
  turtle.back()
  fuel()
  turtle.turnRight()
  fuel()
  turtle.turnRight()
  goodDig()
  turtle.forward()
  fuel()
  goodDigUp()
  turtle.digDown()
  fuel()
  turtle.back()
  fuel()
  turtle.turnLeft()
end

function tunnel (len)
  count = 0
  torch = TORCH_INTERVAL
  while count < len do
    threeByThree()

    --[[Stairs
    fuel()
    turtle.up()
    threeByThree()
    turtle.up()
    threeByThree()
    turtle.down()
    --EndStairs]]--

    if torch == TORCH_INTERVAL then
      plantTunnelTorch()
      torch = 0
    end
    goodDig()
    turtle.forward()
    fuel()
    count = count+1
    torch = torch+1
  end
end

function leftOrRight (dire)
  threeByThree()
  goodDig()
  turtle.forward()
  threeByThree()
  turtle.back()
  fuel()
  if dire == 'l' then
    turtle.turnLeft()
  elseif dire == 'r' then
    turtle.turnRight()
  else
    term.write("Error, bad direction.")
  end
end

function swapDirection(dire)
  if dire == 'l' then
    return 'r'
  elseif dire == 'r' then
    return 'l'
  else
    term.write("Error, bad direction.")
  end
end

--================Main===============--

if numArgs == 1.0 then
  digNum = tonumber(args[1])
  tunnel(digNum)
elseif numArgs == 2.0 or numArgs == 3.0 or numArgs == 4.0 then

  if numArgs > 2.0 then
    intervalWidth = tonumber(args[3])
  else
    intervalWidth = TORCH_INTERVAL
  end

  if numArgs == 4.0 then
    cycle = tonumber(args[4])
  else
    cycle = 1
  end


  digNum = tonumber(args[1])
  direction = args[2]
  if direction ~= 'r' and direction ~= 'l' then
    error("Second argument must be 'r' or 'l'")
  end
  while cycle > 0 do
    tunnel(digNum)
    leftOrRight(direction)
    tunnel(intervalWidth)
    leftOrRight(direction)
    tunnel(digNum)
    if cycle > 1 then
      direction = swapDirection(direction)
      leftOrRight(direction)
      tunnel(intervalWidth)
      leftOrRight(direction)
      tunnel(digNum)
      leftOrRight(direction)
      tunnel(intervalWidth)
      leftOrRight(direction)
      tunnel(digNum)
    end
    cycle = cycle-1
  end
else
  error("Usage: dig [int] opt[l | r]")
end