pave

local tArgs = { ... }

if #tArgs ~= 2 then
        print( "Usage: pave <width>, <length>" )
        return
end

local width = tonumber( tArgs[1] )
if width < 1 then
        print( "Pave width must be positive" )
        return
end

local length = tonumber( tArgs[2] )
if length < 1 then
        print( "Pave length must be positive" )
        return
end

turtle.refuel()

local fuelLevel = turtle.getFuelLevel()
print("Fuel level: "..fuelLevel)
if fuelLevel < 1 then
 return
end

print("paving "..width.." x "..length)
turtle.select(1)

local start = width/2
turtle.turnLeft()
for i=1,start do
  turtle.forward()
end
turtle.turnRight()

local goRight = true
for i=1,length do
  turtle.forward()
  if (turtle.detect()) then
    return
  end

  if (goRight) then
    turtle.turnRight()
  else
    turtle.turnLeft()
  end

  for j=1,width do
    if (j > 1) then
      turtle.forward()
    end
    if (not turtle.detectDown()) then
      turtle.placeDown()
    end
  end

  if (goRight) then
    turtle.turnLeft()
  else
    turtle.turnRight()
  end
  goRight = not goRight
end