Mining Turtle - Intelligent Quarry

--[[
Quarry programm for a turtle.
Features:
- finds adjacent chest
- checks refuel and makes its way back to the chest if out of fuel
- empties its inventory to chest
- some minor intelligence stuff

Note:
- the first argument you pass will determine the start height of the quarry

Copyright Thorsten Schmiedel 2014
Do NOT post this without noticing me! (schmiedel.thorsten@gmail.com)
--]]

-- Variables and constants
-- Constants
local FuelSlot = 1
local ChestSlot = 2

-- Variables
local tArgs = { ... }

local startHeightDiff = 0
local sizeXZ = 16
local debug = true

local dX, dY, dZ;

-- Arguments
if (#tArgs >= 1) then
  startHeightDiff = tonumber(tArgs[1])
  if (#tArgs >= 2) then
    sizeXZ = tonumber(tArgs[2])
  end
end
-- end Arguments

-- FUNCTIONS

-- HELPER FUNCTIONS
local function ForceMoveDown()
  while not turtle.down() do
    turtle.digDown()
    turtle.attackDown()
    sleep(0.2)
  end
end

local function ForceMoveUp()
  while not turtle.up() do
    turtle.digUp()
    turtle.attackUp()
    sleep(0.2)
  end
end

local function CheckFuel()
  local lengthOfWay = startHeightDiff + dX + dY + dZ

  if (lengthOfWay <= turtle.getFuelLevel()) then
    return false
  else
    return true
  end
end


-- Finds a chest adjacent to the turtle
local function FindChest()
  for i = 1, 4 do
    if turtle.detect() then
      if debug then
        print("Chest found!")
      end
      return
    else
    turtle.turnRight()
    end
  end
  if debug then
    print("No adjacent chest found! New attempt in 3 secs")
  end
  return
end

-- Pick up the chest
local function PickUp(slot)
  local tmp = turtle.getSelectedSlot()
  turtle.select(slot)
  if not turtle.dig() and debug then
    print("Error in picking up the chest! Aborting programm!")
  end
  turtle.select(tmp)
end

-- Dig to the begin of the quarry
local function GoToStartHeight()
  if (startHeightDiff == 0) then
    if debug then
    print("Reached startheight! Mining begins...")
    end
    return
  end

  for i = 1, startHeightDiff do
    ForceMoveDown()
  end
  if debug then
    print("Reached startheight! Mining begins...")
  end
end

-- Go back to the chest
local function GoUpToChest()
  if (startHeightDiff == 0) then
    if debug then
      print("Reached chest! Inventory empty begins...")
    end
    return
  end

  for i = 1, startHeightDiff do
    ForceMoveUp()
  end
  if debug then
    print("Reached chest! Inventory empty begins...")
  end
end

-- Mines one column
local function MineColumn(amount)

end


FindChest()
GoToStartHeight()
GoUpToChest()