Minecrew Lumberjack

local invalid = true
local width = 2
local height = 0

function chop()
  turtle.select(1)
  if width == 2 then
    if turtle.detect() then
      repeat turtle.dig() until turtle.forward()
    end
    while turtle.detect() do
      turtle.dig()
      turtle.turnRight()
      if turtle.detect() then
        turtle.dig()
      end
      turtle.turnLeft()
      if turtle.detectUp() then
        turtle.digUp()
        repeat until turtle.up()
        height=height+1
      end
    end
    repeat until turtle.forward()
    turtle.turnRight()
    if turtle.detect() then
      turtle.dig()
    end
    repeat until  turtle.forward()
    turtle.turnLeft()
    for i=1,height do
     repeat turtle.digDown() until turtle.down()
    end
  end
  repeat until turtle.back()
  turtle.turnRight()
  repeat until turtle.back()
  turtle.turnLeft()
  repeat until turtle.back()
end
function replant()
  for i=1,15 do
    turtle.select(i)
    if turtle.compareTo(16) and turtle.getItemCount(i) >3 then
      repeat until turtle.up()
      for i=1,2 do
        repeat until turtle.forward()
        turtle.placeDown()
      end
      for i=1,2 do
        turtle.turnRight()
        repeat until turtle.forward()
        turtle.placeDown()
      end
      repeat until turtle.forward()
      turtle.turnRight()
      repeat until turtle.forward()
      repeat until turtle.down()
      turtle.turnRight()
      break
    end
  end
  print("Ran out of saplings!")
end
function refuel()
  if turtle.getFuelLevel() < 200 then
    for i=1,15 do
      turtle.select(i)
      if not turtle.compareTo(16) then
        turtle.refuel()
      end
    end
  end
end

function empty()
  turtle.turnRight()
  for i=1,15 do
    turtle.select(i)
    if not turtle.compareTo(16) then
      turtle.drop()
    end
  end
  turtle.turnLeft()
end

while true do
  turtle.select(16)
  print("Has the tree grown yet?")
  if not turtle.compare() then
    print("w00t tree has grown! Lets get wood!")
    height = 0
    chop()
    print("Replanting saplings")
    replant()
    print("Checking fuel and refuelling")
    refuel()
    print("Deposit our wood in the chest")
    empty()
  end
  print("Waiting a minute for the tree to grow")
  sleep(60)
end