GPS Enabled Forester

local homex,homey,homez =0,0,0
local cx,cy,cz = 0,0,0
local treeCount = 8
local currentFacing = 0
local treePoints = {}
local debug = false
local currentTree = 1
local sapplingsSlot = 2
local plantsaps = false
local sapsPlantedCount = 0
-- PLANT SAPS -------------------------------------
function PlantSapling()
-- plant sap
CheckSaps()
TurnRight(1)
GoForward(1)
turtle.digDown()
turtle.select(1)
turtle.placeDown()
turtle.back()
turtle.select(sapplingsSlot)
turtle.place()
IncSapCount()
TurnLeft(1)
end
-- QUICK TURN ----------------------------------
function Turn(direction)
if direction == 0 then
  if currentFacing == 1 then
   TurnLeft(1)
  elseif currentFacing == 2 then
   TurnRight(2)
  elseif currentFacing == 3 then
   TurnRight(1)
  end
elseif direction == 1 then
  if currentFacing == 2 then
   TurnLeft(1)
  elseif currentFacing == 3 then
   TurnRight(2)
  elseif currentFacing == 0 then
   TurnRight(1)
  end
elseif direction == 2 then
  if currentFacing == 3 then
   TurnLeft(1)
  elseif currentFacing == 0 then
   TurnRight(2)
  elseif currentFacing == 1 then
   TurnRight(1)
  end
else -- direction 3
  if currentFacing == 0 then
   TurnLeft(1)
  elseif currentFacing == 1 then
   TurnRight(2)
  elseif currentFacing == 2 then
   TurnRight(1)
  end
end
end
-- CHECK SAPS ----------------------------------
function CheckSaps()
term.clear()
if turtle.getItemCount(sapplingsSlot) < 1 then
  print("I need more sapplings.")
  print("Are they in my inventory yet? Press any key to continue.")
  local event, param1 = os.pullEvent ("char")
end
end
-- TURNING -------------------------------------
function TurnRight(times)
-- turning right
for i=1,times do
  turtle.turnRight()
  currentFacing = currentFacing +1
  if currentFacing == 4 then
   currentFacing = 0
  end
end
end
function TurnLeft(times)
-- turning left
for i=1,times do
  turtle.turnLeft()
  currentFacing = currentFacing -1
  if currentFacing < 0 then
   currentFacing = 3
  end
end
end
-- MOVING -------------------------------------
function GoForward(times)
-- move some
for i=1,times do
  if turtle.detect() then
   turtle.dig()
  end
  turtle.forward()
end
end
-- DROP OFF ------------------------------------
function DropOff()
if AtHome ~= true then
  GoHome()
end
-- face north
Turn(0)
-- move back
turtle.back()
-- drop off stuff
turtle.select(3)
local logs = turtle.getItemCount(3)
for i=4,logs do
  redstone.setOutput("bottom", true)
  sleep(0.3)
  redstone.setOutput("bottom", false)
  sleep(0.3)
end
for i=1,GetSapCount() do
  redstone.setOutput("back", true)
  sleep(0.3)
  redstone.setOutput("back", false)
  sleep(0.3)
end
TurnRight(2)
end
-- GET FACING----------------------------------
function GetFace()
local oldx,oldy,oldz = GetPos()
GoForward(1)
GetPos()
print("check direction")
if cx > oldx then
  currentFacing = 3
elseif cx < oldx then
  currentFacing  = 1
elseif cy > oldy then
  currentFacing = 0
else
  currentFacing = 2
end
end
-- AT HOME CHECK -------------------------------
function AtHome()
GetPos()
if cx == homex then
  if cy == homey then
   if cz == homez then
	return true
   else
	return false
   end
  else
   return false
  end
else
  return false
end
end
-- GO HOME -------------------------------------
function GoHome()
GetPos()
while AtHome() ~=true do
  if cy > homey then -- too far north
   Turn(2)
   print("facing south")
   print("moving "..math.abs(cy-homey).."meters")
   GoForward(math.abs(cy-homey)) --go south
   if cx > homex then -- to far west
	Turn(1)
	print("facing east")
   elseif cx < homex then -- too far east
	Turn(3)
	print("facing west")
   end
   print("moving "..math.abs(cx-homex).."meters")
   GoForward(math.abs(cx-homex)) -- go e or w
   Turn(0)
   print("facing north")
  elseif cy < homey then -- too far south
   Turn(0)
   print("facing north")
   print("moving "..math.abs(cy-homey).."meters")
   GoForward(math.abs(cy-homey)) -- go north
   if cx > homex then -- too far east
	Turn(3)
	print("facing south")
   elseif cx < homex then -- to far west
	Turn(1)
	print("facing north")
   end
   print("moving "..math.abs(cx-homex).."meters")
   GoForward(math.abs(cx-homex)) --go e or w
   Turn(0)
  else -- already on right y axis
   if cx > homex then -- too far east
	Turn(1)
	print("facing west")
   elseif cx < homex then -- to far west
	Turn(3)
	print("facing east")
   end
   print("moving "..math.abs(cx-homex).."meters")
   GoForward(math.abs(cx-homex)) --go e or w
   Turn(0)
  end
  while cz > homez do
   print("moving down")
   turtle.down()
   GetPos()
  end
end
Turn(0)
end
-- GO To TREE ----------------------------------
function GoToTree(nu)
GetPos()
if cx < treePoints[nu]['x']+1 then
  -- not on east side of it
  Turn(3)
  GoForward(math.abs(cx-treePoints[nu]['x'])+1)
elseif  cx > treePoints[nu]['x']+1 then
  Turn(1)
  GoForward(math.abs(cx-treePoints[nu]['x'])-1)
end
if  cy < treePoints[nu]['y'] then
  -- not near it
  Turn(0)
  GoForward(math.abs(cy-treePoints[nu]['y']))
elseif cy > treePoints[nu]['y'] then
  Turn(2)
  GoForward(math.abs(cy-treePoints[nu]['y']))
end
end
-- CHECK WOOD ----------------------------------
function CheckWood()
Turn(1)
turtle.select(2) -- mob nudge error
if turtle.compare() ~= true then
  turtle.place()
end
turtle.select(3)
if turtle.compare() then
  MineWood()
end
return false
end
-- MINE WOOD -----------------------------------
function MineWood()
turtle.dig()
turtle.forward()
while turtle.detectUp() do
  turtle.digUp()
  turtle.up()
end
while turtle.detectDown() ~= true do
  turtle.down()
end
turtle.back()
CheckSaps()
turtle.select(sapplingsSlot)
IncSapCount()
turtle.place()
end
-- SET TREE PLACES -----------------------------
function SetTreePoints(treeCount)
for i=1,treeCount do
  table.insert(treePoints, {x=homex,y=(i*4)+homey,z=homez})
  if debug == true then
   print(i .. treePoints[i]['x']..":X "..treePoints[i]['y']..":Y "..treePoints[i]['z']..":Z")
  end
end
end
-- GET POSITION  -------------------------------
function GetPos()
cx,cy,cz = gps.locate(1,false)
sleep(0.2) -- make sure gps gets signal (i think)
print("I am at "..cx..":x "..cy..":y "..cz..":z")
return gps.locate(1,false)
end
-- ADD SAP COUNT -------------------------------
function IncSapCount()
sapsPlantedCount = sapsPlantedCount +1
end
-- GET SAP COUNT AND RESET ---------------------
function GetSapCount()
local tmp = sapsPlantedCount
sapsPlantedCount = 0
return tmp
end
-- END OF FUNCTIONs-----------------------------
function start(x, y, z, sap, count)
term.clear()
if peripheral.isPresent("right")~=true then
  print("Requires Wireless Turtle")
else
  rednet.open("right")
  homex,homey,homez = gps.locate(2, false)
  local argCount = 0
  if x~=nil then
   homex = x
  else
   argCount = argCount +1
  end
  if y~=nil then
   homey = y
  else
   argCount = argCount +1
  end
  if z~=nil then
   homez = z
  else
   argCount = argCount +1
  end
  if argCount ~= 3 or argCount ~=0 then
   term.clear()
   print("Requires none or all positions | treeAPI.start( [x,y,z] )")
   print("e.g. treeAPI.start()")
   print("or")
   print("treeAPI.start(10,5,50)")
   print(argCount)
  end
  print("Place Dirt in slot 1, sapplings in 2 and wood block in 3.")
  if sap==nil and count ==nil then -- manual input
   print("do you want to plant saplings first? Y/N")
   local event, param1 = os.pullEvent ("char")
   if param1 == "y" then
	plantsaps = true
   end
   term.clear()
   print("Planting "..treeCount.." saplings. is this correct? Y/N")
   local event, param1 = os.pullEvent ("char")
   if param1 == "n" then
	print("How many do you want to plant?")
	local event, param1 = os.pullEvent ("char")
	print("will now plant "..param1)
	treeCount = param1
   end
  end
  GetFace()
  GoHome()
  SetTreePoints(treeCount)
  if plantsaps == true then
   for i=1,treeCount do
	GoToTree(i)
	PlantSapling()
   end
  end
-- MAIN LOOP --------------------------------
  while true do
   for i=1,treeCount do
	GoToTree(i)
	CheckWood()
   end
   -- avoiding plants
   -- TurnLeft(1)
   -- GoForward(1)
   -- TurnRight(1)
   -- GoForward(2)
   -- TurnRight(1)
   GoHome()
   DropOff()
  end
end
end