GetLava42

args = {...}
Horizontal = 0
if args[1] ~= nil then
  Horizontal = tonumber(args[1])
end
if args[1] == nil then
  print("Proper usage: getlavaNN numLeftRightStart")
  return
end

X = 0
Y = 0
Z = 0

FarthestXThisRun = 0

function UseBucket()
  turtle.select(2)
  if turtle.placeDown() == true then
    return true
  else
    return false
  end
end

function MoveForward()
  if turtle.forward() == true then
    X=X+1
    if X > FarthestXThisRun then
      FarthestXThisRun = X
    end
    return true
  else
    return false
  end
end

function MoveBack()
  if turtle.back() == true then
    X=X-1
    return true
  else
    return false
  end
end

function MoveDown()
  if turtle.down() == true then
    Z=Z-1
    return true
  else
    return false
  end
end

function MoveUp()
  if turtle.up() == true then
    Z=Z+1
    return true
  else
    return false
  end
end

function rewind()
  while Z < 0 do
    if MoveUp() == false then
        print("ceiling issue")
    end
  end
  while X > 0 do
    if MoveBack() == false then
       print("backboard issue")
    end
  end
end

function forwardwind()
  for i=0, FarthestXThisRun, 1 do
    MoveForward()
  end
end

function useFuel()
  turtle.select(1)
  turtle.transferTo(16,2)
  turtle.select(16)
  turtle.refuel()
end

function refuel()
  if turtle.getFuelLevel() < 10000 then
    turtle.select(1)
    if turtle.getItemCount() > 4 then
      useFuel()
    else
      print("Out of fuel!")
      rewind()
      UnHorizon()
      pitStop()
      print("All refueled.")
      AdjustHorizontal()
      forwardwind()
    end
  end
end

function gotbuckets()
  turtle.select(2)
  if turtle.getItemCount() < 2 then
    return false
  else
    return true
  end
end

function sort()
  for i=1, 2, 1 do
    turtle.select(i)
    for b=3, 16, 1 do
      if turtle.compareTo(b) == true then
        turtle.select(b)
        turtle.transferTo(i)
        turtle.select(i)
      end
    end
  end
end

function SortSuck()
  for i=3, 16, 1 do
    turtle.suck()
  end
  sort()
  for i=3, 16, 1 do
    turtle.select(i)
    turtle.drop()
  end
end

function GotSpace()
  local rem = turtle.getSelectedSlot()
  turtle.select(15)
  if turtle.getItemCount() > 0 then
    turtle.select(rem)
    return false
  else
    turtle.select(rem)
    return true
  end
end

function AdjustHorizontal()
  turtle.forward()
  turtle.forward()
  turtle.forward()
  if Horizontal >= 0 then
    turtle.turnRight()
    for i=0, Horizontal, 1 do
      turtle.forward()
    end
    turtle.turnLeft()
  end
  if Horizontal < 0 then
    turtle.turnLeft()
    for i=0, (Horizontal*(-1)), 1 do
      turtle.forward()
    end
    turtle.turnRight()
  end
end

function UnHorizon()
  if Horizontal > 0 then
    turtle.turnLeft()
    for i=0, Horizontal, 1 do
      turtle.forward()
    end
    turtle.turnRight()
  end
  if Horizontal < 0 then
    turtle.turnRight()
    for i=0, (Horizontal*(-1)), 1 do
      turtle.forward()
    end
    turtle.turnLeft()
  end
  turtle.back()
  turtle.back()
  turtle.back()
end

function pitStop()
    turtle.turnRight()
    SortSuck()
    turtle.turnLeft()
    turtle.turnLeft()
    SortSuck()
    turtle.turnRight()
    refuel()
end

pitStop()

while turtle.getFuelLevel() < 200 do
  refuel()
end

while turtle.getFuelLevel() > 100 do
  AdjustHorizontal()
  forwardwind()

  while GotSpace() == true and gotbuckets() == true do
    while turtle.getFuelLevel() < 200 do refuel() end
    UseBucket()
    if MoveDown() == false then
      while Z < 0 do MoveUp() end
      if MoveForward() == false then
        print("BRICK WALL!")
        print("Old Horizontal:", Horizontal)
        rewind()
        if Horizontal >= 0 then
          Horizontal = Horizontal + 1
          turtle.turnRight()
          if turtle.forward() == false then
            print("End of run reached.")
            turtle.turnLeft()
            UnHorizon()
            pitStop()
            print("All done!")
            return
          end
          turtle.turnLeft()
        end
        if Horizontal < 0 then
        Horizontal = Horizontal - 1
          turtle.turnLeft()
          if turtle.forward() == false then
            print("End of run reached.")
            turtle.turnRight()
            UnHorizon()
            pitStop()
            print("All done!")
            return
          end
          turtle.turnRight()
        end
        print("New Horizontal:", Horizontal)
        FarthestXThisRun = 0
      end
    end
  end

  rewind()
  UnHorizon()
  pitStop()
end

rewind()
UnHorizon()