TowerBuilder (Alpha Build)

-- Tower Builder by Robin | robinschoors.com

-- Settings (You can change these (: )
local fuel = true       -- Change to false if your turtle doesn't use fuel
local totalSlots = 16-1 -- Change to 9 if you have an older version! Leave the -1 alone please. :P
local tightLoop = 0.25  -- Change this to a higher value if the server lags because of the program
-- Initial variables
local tArgs = {...}
local width, length, height, inventory
local totalBlocksPlaced = 0
local success = false

-- Check initial variables
if tArgs[1] == nil or tArgs[2] == nil or tArgs[3] == nil then
  error("Error!\n\tUSAGE:\n\ttowerBuilder <width> <length> <height>\n\te.g. towerBuilder 4 4 8")
else
  width  = tonumber(tArgs[1])
  length = tonumber(tArgs[2])
  height = tonumber(tArgs[3])
end

-- Clever functions go here
function hasFuel()
  if fuel == true then
    if turtle.getFuelLevel()<=0 then
      turtle.select(1)
      return false
    else
      return true
    end
  else
    return true
  end
end

function autoSelect() -- Automatically selects slot with items
  for i=1,totalSlots do
    if turtle.getItemCount(i)>0 then
      turtle.select(i)
      return true
    end
    i = i+1
  end
  return false
end

function clearInventory() -- Clear inventory from anything but the building blocks
  for i=1,totalSlots do
    turtle.select(totalSlots+1)
    if turtle.compareTo(i)==false then
      turtle.select(i)
      turtle.drop()
    end
  end
end

function totalBlocksNeeded() -- returns total blocks needed for build
  return width * length * height
end

function checkInventory() -- Count all blocks in inventory and stores it in inventory var
  inventory = 0
  for i=1,totalSlots do
    inventory = inventory + turtle.getItemCount(i)
    i = i+1
  end
  return inventory
end

function checkBlocksNeeded() -- Returns blocks that need to be added to complete the build
  return totalBlocksNeeded()-inventory-totalBlocksPlaced
end

function canPlaceBlock() -- Checks if Turtle can place a block
  checkInventory()
  if inventory == 0 then
    return false
  else
    return true
  end
end

function fuelCheckOnMove()
  if fuel==true then
    if hasFuel() == false then
      print "Out of fuel! Put some fuel in my first slot. I'll automatically turn it into energy! :)"
      while hasFuel()==false do
        turtle.refuel()
        hasFuel()
        os.sleep(tightLoop)
      end
      print "Resuming build in 5 seconds..."
      sleep(5)
    end
  end
end

function moveUp() -- Move up 1 level Checks for gravel or other players that may be obstructing the path
  fuelCheckOnMove()
  success = false
  while success==false do
    while turtle.detectUp() do
      turtle.digUp()
    end
    success=turtle.up()
  end
end

function forward() -- Move forward. Checks for gravel or other players that may be obstructing the path
  fuelCheckOnMove()
  success = false
  while success==false do
    while turtle.detect()==true do
      turtle.dig()
      clearInventory()
    end
    success=turtle.forward()
  end
end

function placedBlock() -- Doing some additional calculations after placing a block
  totalBlocksPlaced = totalBlocksPlaced + 1
end

function placeDown() -- place block beneath the turtle
  success = false
  while success == false do
    if canPlaceBlock()==false then
      print "Ran out of blocks to place. Will resume after blocks are added to inventory!"
      while inventory<=0 do
        checkInventory()
        sleep(tightLoop)
      end
      print "Resuming build in 5 seconds..."
      sleep(5)
    end
    autoSelect()
    success = turtle.placeDown()
    if turtle.detectDown()==true then
      success = true
    end
  end
  placedBlock()
end

function turnRight()
  success = false
  while success==false do
    success = turtle.turnRight()
  end
end

function turnLeft()
  success = false
  while success==false do
    success = turtle.turnLeft()
  end
end

function buildLength()
  for i=1,length do
    placeDown()
    forward()
  end
end

function buildWidth()
  for i=1,width do
    placeDown()
    forward()
  end
end

function buildLevel()
  moveUp()

  buildLength()
  turnLeft()
  buildWidth()
  turnLeft()
  buildLength()
  turnLeft()
  buildWidth()
  turnLeft()
end

function build()
  turnRight()
  for x=1,height do
    buildLevel()
  end
end

-- Doing the build
print("I'm gonna need " .. totalBlocksNeeded() .. " to build this. Starting build...\n")
build()