Turtle - Spruce Farm

local treeSize = 2
local treeCount = 2
local treeDistance = 4

local function refuel()
    local currentSlot = turtle.getSelectedSlot()
    turtle.select(1)
    if not turtle.refuel(1) then
        print("Waiting for fuel!")
        while not turtle.refuel(1) do
        end
    end
    turtle.select(currentSlot)
end

local function moveForward()
    refuel()
    return turtle.forward()
end

local function moveUp()
    refuel()
    turtle.up()
end

local function moveDown()
    refuel()
    turtle.down()
end

local function moveBack()
    refuel()
    turtle.back()
end

local function moveForwardForce()
	while not moveForward() do
		turtle.dig()
	end
end

local function harvestTree()
    print("Harvesting tree")
    turtle.dig()
    turtle.forward()
    turtle.select(3)
    if treeSize == 1 then
        print("Tree Size 1")
        local treeHeight = 1
        while turtle.compareUp() do
            turtle.digUp()
            moveUp()
            treeHeight = treeHeight + 1
        end
        print("Tree Height:",treeHeight)
        while turtle.detectDown() == false do
            moveDown()
        end
        turtle.back()
        turtle.select(2)
        turtle.place()
    elseif treeSize == 2 then
        while turtle.compareUp() do
            turtle.dig()
            turtle.digUp()
            moveUp()
        end
        turtle.dig()
        turtle.turnRight()
        turtle.dig()
        moveForward()
        turtle.turnLeft()
        while turtle.compareDown() do
            turtle.dig()
            turtle.digDown()
            moveDown()
        end
        turtle.dig()
        turtle.select(2)
        turtle.place()
        turtle.turnLeft()
        moveForward()
        turtle.turnRight()
        turtle.place()
        turtle.turnRight()
        turtle.place()
        turtle.turnLeft()
        moveBack()
        turtle.place()
    end
end

local function doTreeIteration()
	turtle.turnLeft()
    turtle.select(2)
    if turtle.compare() then
        print("Tree not ready.")
    end
    turtle.select(3)
    if turtle.compare() then
        print("Harvesting tree")
        harvestTree()
    else
        error("Unexpected tree grew!")
    end
	turtle.turnRight()
end

local function doInventoryManagement()
	turtle.turnLeft()
	turtle.select(1)
	turtle.suck(turtle.getItemSpace())
	turtle.turnRight()
	turtle.turnRight()
	turtle.select(2)
	turtle.suck(turtle.getItemSpace())
	turtle.turnLeft()
	for i=4,16,1 do
		turtle.select(i)
		turtle.dropDown()
	end
end

local function runPath()
	moveForwardForce()
	doTreeIteration()
	for i=2,treeCount,1 do
		for j=1,treeDistance,1 do
			moveForwardForce()
		end
		doTreeIteration()
	end
	turtle.turnLeft()
	turtle.turnLeft()
	for i=2,treeCount,1 do
		for j=1,treeDistance,1 do
			moveForwardForce()
		end
	end
	moveForwardForce()
	turtle.turnRight()
	turtle.turnRight()
	doInventoryManagement()
end

runPath()