Smart Turtle API V2

--SmartTurtleV2 By Jeremiah Lowe
--(c) Jeremiah Lowe 2018
--A simple turtle library for allowing
--the easy creation of turtle scripts

local fuelSlot = 1
local fuelBufferSize = 10
local autoRefuel = false
local direction = 0
local invHomeName = nil
local invFullCallback = nil
local invTempHome = "_inv_tmp_hme"
local homes = {}

--    Fwd (0)
--Lft (3)  Rgt (1)
--    Bwd (2)

local function normalize(val)
  while val > 3 do val = val - 4 end
  while val < 0 do val = val + 4 end
  return val
end
local function _dirChg(by) direction = normalize(direction + by) end
local function _movChg(by)
  for k, h in pairs(homes) do
    if direction == 0 then
      homes[k].movementY = h.movementY + by
    elseif direction == 1 then
      homes[k].movementX = h.movementX + by
    elseif direction == 2 then
      homes[k].movementY = h.movementY - by
    elseif direction == 3 then
      homes[k].movementX = h.movementX - by
    end
  end
end
local function _dptChg(by)
  for k, h in pairs(homes) do
    homes[k].depthChange = h.depthChange + by
  end
end
local function _autoRefuel(amt)
  if not autoRefuel then return end
  tamt = amt + fuelBufferSize
  if tamt > turtle.getFuelLimit() then
    tamt = turtle.getFuelLevel()
  end
  slot = turtle.getSelectedSlot()
  turtle.select(fuelSlot)
  if turtle.getFuelLevel() < tamt then print("Refuelling") end
  while turtle.getFuelLevel() < tamt do
    turtle.refuel(1)
  end
  turtle.select(slot)
end
local function _rotateHome(h)
  if not pointTo(h.direction) then return false end
  return true
end
local function _fwdAbsVal(val)
  amt = val
  if val < 0 then amt = -val end
  return forward(amt)
end
local function _moveHome(h)
  --X axis
  if h.movementX ~= 0 then
    d = 3
    if h.movementX < 0 then d = 1 end
    if not pointTo(d) then return false end
    if not _fwdAbsVal(h.movementX) then return false end
  end
  if h.movementY ~= 0 then
    d = 2
    if h.movementY < 0 then d = 0 end
    if not pointTo(d) then return false end
    if not _fwdAbsVal(h.movementY) then return false end
  end
  return true
end
local function _depthHome(h)
  depthDir = 1
  reposAmt = -h.depthChange
  if h.depthChange > 0 then
    depthDir = -1
    reposAmt = h.depthChange
  end
  for i=1, reposAmt do
    if depthDir > 0 then
      if not turtle.up() then return false end
    else
      if not turtle.down() then return false end
    end
    _dptChg(depthDir)
  end
  return true
end
local function _goHome(h)
  if h == nil then error("Home object expected, got nil!") end
  if not _depthHome(h) then return false end
  if not _moveHome(h) then return false end
  if not _rotateHome(h) then return false end
  return true
end
function turnLeft(amt)
  if amt == nil then amt = 1 end
  for i=1,amt do
    if turtle.turnLeft() then _dirChg(-1)
    else return false end
  end
  return true
end
function turnRight(amt)
  if amt == nil then amt = 1 end
  for i=1,amt do
    if turtle.turnRight() then _dirChg(1)
    else return false end
  end
  return true
end
function forward(amt, digF)
  if amt == nil then amt = 1 end
  if digF == nil then digF = false end
  _autoRefuel(amt)
  for i=1,amt do
    if turtle.forward() then
      _movChg(1)
    else
      if not digF then
        return false
      elseif dig() and turtle.forward() then _movChg(1)
      else return false end
    end
  end
  return true
end
function back(amt) return backward(amt) end
function backward(amt)
  if amt == nil then amt = 1 end
  _autoRefuel(amt)
  for i=1,amt do
    if turtle.back() then _movChg(-1)
    else return false end
  end
  return true
end
function up(amt, dig)
  if amt == nil then amt = 1 end
  if dig == nil then dig = false end
  _autoRefuel(amt)
  for i=1,amt do
    if turtle.up() then
      _dptChg(1)
    else
      if not dig then
        return false
      elseif digUp() and turtle.up() then _dptChg(1)
      else return false end
    end
  end
  return true
end
function down(amt, dig)
  if amt == nil then amt = 1 end
  if dig == nil then dig = false end
  _autoRefuel(amt)
  for i=1,amt do
    if turtle.down() then
      _dptChg(-1)
    else
      if not dig then
        return false
      elseif digDown() and turtle.down() then _dptChg(-1)
      else return false end
    end
  end
  return true
end
local function _checkInv()
  if invHomeName ~= nil and isInventoryFull() then
    createHome(invTempHome)
    home(invHomeName)
    if invFullCallback ~= nil then
      invFullCallback()
    end
    home(invTempHome)
  end
end
function digUp()
  _checkInv()
  return turtle.digUp()
end
function digDown()
  _checkInv()
  return turtle.digDown()
end
function dig()
  _checkInv()
  return turtle.dig()
end
function getDepth() return depthChange end
function getMovementX() return movementX end
function getMovementY() return movementY end
function getDirection() return direction end
function pointTo(toDir)
  left = true
  d = direction - toDir
  d2 = 4 - d
  if d > d2 then left = false end
  if left then
    while direction ~= toDir do
      if not turnLeft() then return false end
    end
  else
    while direction ~= toDir do
      if not turnRight() then return false end
    end
  end
  return true
end
function goHome(homeName)
  if homeName == nil then error("No home name provided!") end
  h = homes[homeName]
  if h == nil then error("No home with name " .. homeName .. " exists!") end
  return _goHome(h)
end
function home(homeName) return goHome(homeName) end
local function _homeObj()
  local h = {}
  h.movementX = 0
  h.movementY = 0
  h.depthChange = 0
  h.direction = direction
  return h
end
function createHome(homeName)
  if homeName == nil then error("No home name provided!") end
  homes[homeName] = _homeObj()
end
function getFreeSlots()
  free = 0
  for i=1,16 do
    if turtle.getItemCount(i) == 0 then free = free + 1 end
  end
  return free
end
function turnAround(amt)
  if amt == nil then amt = 1 end
  turnRight(2 * amt)
end
function isInventoryFull()
  for i=1,16 do
    local a = turtle.getItemCount(i)
    if a == 0 then return false end
  end
  return true
end
function setInventoryFullHome(homeName) invHomeName = homeName end
function getInventoryFullHome() return invHomeName end
function setInventoryFullCallback(cback) invFullCallback = cback end
function getInventoryFullCallback() return invFullCallback end
function enableAutoRefuel() autoRefuel = true end
function disableAutoRefuel() autoRefuel = false end
function setFuelSlot(slot)
  if slot < 0 then return false end
  if slot > 16 then return false end
  fuelSlot = slot
  return true
end
function getFuelSlot() return fuelSlot end
function getFuelBufferSize() return fuelBufferSize end
function setFuelBufferSize(size)
  if size < 0 then return false end
  if size > turtle.getFuelLimit() then return false end
  fuelBufferSize = size
  return true
end