Upgraded

local tArgs = {...}
if #tArgs ~= 3 then
  print("Requires length, width, height")
  return
end

local x = tonumber(tArgs[1]) - 1
local y = tonumber(tArgs[2])
local z = tonumber(tArgs[3])

local posX = 1
local posY = 1
local posZ = 1

if x == nil or y == nil or z == nil then
  print("Invalid dimensions")
  return
end

if x < 0 or y < 0 or z < 0 then
  print("Invalid (negative) dimensions")
  return
end

local torch = 0
local inventory_start = 2
print("Use torches? (y/n)")
local input = io.read()
if(input == "y") then
  torch = 2
  inventory_start = 3
else
  torch = 0
end

local roomSize = x * y * z
print("Storing fuel for mining process...")
turtle.select(1)
while turtle.getFuelLevel() < roomSize do
  if not turtle.refuel(1) then
    print("Not enough fuel. Please insert more fuel.")
    return
  end
end



local direction = true
for i = 1, z do
  roomSize = x * y * (z-i)
  while turtle.getFuelLevel() < roomSize do
    turtle.select(1)
    turtle.refuel(1)
  end

  for j = 1, y do
    for k = 1, x do
      turtle.dig()
      turtle.forward()
      if direction then
        posX = posX + 1
      else
        posX = posX - 1
      end
      if(torch ~=0 and z > 1 and y > 1 and (j+3) % 6 == 0 and i == 1 and k < x and (k == 1 or k % 6 == 0)) then
        turtle.turnLeft()
        turtle.select(2)
        turtle.place()
        turtle.turnRight()
      end
    end
    if j < y then
      if direction then
        turtle.turnRight()
        turtle.dig()
        turtle.forward()
        posY = posY + 1
        turtle.turnRight()
        direction = false
      else
        turtle.turnLeft()
        turtle.dig()
        turtle.forward()
        posY = posY + 1
        turtle.turnLeft()
        direction = true
      end
    end
    if(turtle.getItemCount(16) > 0) then
        goUnload(i, j, k, direction)
  end
  if i < z then
    turtle.digUp()
    turtle.up()
    posZ = posZ + 1
    turtle.turnRight()
    turtle.turnRight()
  end
end




if z % 2 == 0 then
  for i = 1, z do
    turtle.down()
    posZ = posZ - 1
  end
  turtle.turnRight()
  for inventory = inventory_start, 16 do
    turtle.select(inventory)
    turtle.drop()
  end
  turtle.turnRight()
else
  if y % 2 == 0 then
    turtle.turnRight()
    for i = 1, y-1 do
      turtle.forward()
      posY = posY - 1
    end
    for i = 1, z do
      turtle.down()
      posZ = posZ - 1
    end
    for inventory = inventory_start, 16 do
      turtle.select(inventory)
      turtle.drop()
    end
    turtle.turnRight()
  else
    turtle.turnLeft()
    for i = 1, y-1 do
      turtle.forward()
      posY = posY - 1
    end
    turtle.turnLeft()
    for i = 1, x-1 do
      turtle.forward()
      posX = posX - 1
    end
    for i = 1, z do
      turtle.down()
      posZ = posZ - 1
    end
    turtle.turnRight()
    for inventory = inventory_start, 16 do
      turtle.select(inventory)
      turtle.drop()
    end
    turtle.turnRight()
  end
end


function goUnload(i, j, k, direction)
  if direction then
    turtle.turnLeft()
  else
    turtle.turnRight()
  for m = 1, j-1 do
    turtle.forward()
  end
  turtle.turnLeft()
  for m = 1, k-1 do
    turtle.forward()
  end
  for m = 1, i-1 do
    turtle.down()
  end
  turtle.turnRight()
  for inventory = inventory_start, 16 do
    turtle.select(inventory)
    turtle.drop()
  end
  turtle.turnRight()
  for m = 1, i-1 do
    turtle.up()
  end
  for m = 1, k-1 do
    turtle.forward()
  end
  turtle.turnRight()
  for m = 1, j-1 do
    turtle.forward()
  end
  if direction then
    turtle.turnLeft()
  else
    turtle.turnRight()
end