tArgs = {...}

local fuelSlot, chestSlot = 16, 15
local height = 0

function goUp(distance)
  if distance == nil then distance = 1 end
  shell.run("go", "up", distance)
end

function goDown(distance)
  if distance == nil then distance = 1 end
  shell.run("go", "up", distance)
end

function goForward(distance)
  if distance == nil then distance = 1 end
  shell.run("go", "forward", distance)
end

function goBack(distance)
  if distance == nil then distance = 1 end
  shell.run("go", "back", distance)
end

function digUp(distance)
  if distance == nil then distance = 1 end
  for i = 1, distance do
    while turtle.detectUp() == true do
	  turtle.digUp()
	  sleep(0.5)
	end
	if distance > 1 then
	  goUp()
	end
  end
end

function dig(distance)
  if distance == nil then distance = 1 end
  for i = 1, distance do
    while turtle.detect() == true do
	  turtle.dig()
	  sleep(0.5)
	end
  end
end

function digDown(distance)
  if distance == nil then distance = 1 end
  for i = 1, distance do
	turtle.digDown()
	sleep(0.5)
	if distance > 1 then
	  goDown()
	end
  end
end

function getFuel()
  return turtle.getFuelLevel()
end

function returnToStart()
  goDown(height)
  height = 0
end

function dropLoad()
  shell.run("turn", "around")
  for i = 1, 14 do
    turtle.select(i)
	turtle.drop()
  end
  turtle.select(1)
end

if tArgs[1] == "-h" then
  print("Usage: lumberjack <redwood>")
elseif tArgs[1] == nil then
  if turtle.getItemCount(chestSlot) == 0 or turtle.getItemCount(fuelSlot) == 0 then
    print("Please insert a chest into slot "..chestSlot.." and fuel into slot "..fuelSlot..", then run lumberjack again")
  else 	 
    shell.run("turn", "around")
    turtle.select(chestSlot)
	turtle.place()
	turtle.select(1)
	shell.run("turn", "around")
	dig()
	goForward()
	while turtle.detectUp() == true do
	  digUp()
	  goUp()
	  height = height + 1
	  if getFuel() == 0 then
	    turtle.select(fuelSlot)
		turtle.refuel(5)
		turtle.select(1)
	  end
	end
	returnToStart()
	dropLoad()
  end
elseif tArgs[1] == "redwood" then
  if turtle.getItemCount(chestSlot) == 0 or turtle.getItemCount(fuelSlot) == 0 then
    print("Please insert a chest into slot "..chestSlot.." and fuel into slot "..fuelSlot..", then run lumberjack again")
  else
    shell.run("turn", "around")
	turtle.select(chestSlot)
	turtle.place()
	turtle.select(1)
	shell.run("turn", "around")
	dig()
	goForward()
	while turtle.detectUp() == true do
	  shell.run("turn", "right")
	  dig()
	  shell.run("turn", "left")
	  dig()
	  goForward()
	  shell.run("turn", "right")
	  dig()
	  shell.run("turn", "left")
	  goBack()
	  digUp()
	  goUp()
	  height = height + 1
	  if getFuel() == 0 then
	    turtle.select(fuelSlot)
		turtle.refuel(5)
		turtle.select(1)
	  end
	end
	if turtle.detect() == true then
	  dig()
	  shell.run("turn", "right")
	  dig()
	  shell.run("turn", "left")
	  goForward()
	  shell.run("turn", "right")
	  dig()
	  shell.run("turn", "left")
	  goBack()
	end
	returnToStart()
	dropLoad()
  end
else
  print("Usage: lumberjack <redwood>")
end