ComputerCraft Turtle Tree Harvester

function aboutFace()-- simply turns the turtle 180 degrees.
    turtle.turnLeft()
    turtle.turnLeft()
end

function grabFuel()-- takes fuel from chest behind turtle for autoRefuel()
  if turtle.getItemCount(16) >= 2 then
    print("No need to grab fuel!")
  else
    print("Grabbing Fuel!")
    sleep(1)
    aboutFace()
    turtle.select(16)
    turtle.suck(2)
    aboutFace()
  end
    if turtle.getItemCount(16) == 0 then
    print("Couldn't retrieve fuel from chest!")
    elseif turtle.getItemCount(16) == 1 then
    print("Only grabbed 1 fuel!")
    else
    print("Fuel grabbed!")

  end
end

function autoRefuel() -- Automatically refuels turtle from chest.
        turtle.select(16)
        print("Selecting slot 16 for fuel check.")
        sleep(2)
        print("Fuel level is " ..turtle.getFuelLevel().. ".")
        sleep(1)
        print("Less than 80 requires a refuel!")
        sleep(1)
        print("STANDBY...")
        sleep(1)
    if turtle.getItemCount(16) < 2 then
        grabFuel()
    end

    if turtle.getFuelLevel() < 80 and turtle.getItemCount(16) >= 2 and turtle.refuel(0) == true then
        sleep(2)
        print("Refueling")
        sleep(2)
        turtle.refuel(2)--Refuels using 2 fuel.
        print("Refueled")
        --checks fuel level and if you put 2 fuel in slot 16 if not goes to manual refuel"manRefuel()"
    elseif turtle.getFuelLevel() < 80 and turtle.getItemCount(16) < 2 then
        manRefuel()
        -- checks fuel level if not needed prints it.
    elseif turtle.getFuelLevel() >= 80 then
        print("No fuel needed.")
    end
end

function manRefuel()
    print("There was either no fuel in the chest,")
    print("Not enough fuel in the chest.")
    print("Or there is no chest.")
    print("Please add fuel manually to slot 16.") --Manually refuel your turtle instead.
    sleep(3)
    --checks fuel level and if selected slot is fuel or has fuel.
    --waits 10 seconds for you to add fuel
    if turtle.getFuelLevel() < 80 and turtle.refuel(0) == false then
        print("Waiting 10 seconds for fuel.")
        sleep(10)
    end
    --and trys refueling again.
    if turtle.getItemCount(16) >= 2 then
        print("Thank you. Refueling!")
        turtle.refuel(2)--Refuels using 2 fuel.
    elseif turtle.getItemCount(16) == 1 then
        print("Only 1 fuel detected!")
        sleep(1)
        print("Add 1 more within 5 seconds!")
        sleep(5)
    end

    --If you didn't add fuel to turtle, it aborts the program.
    if turtle.getFuelLevel() < 80 and turtle.getItemCount(16) < 2 then
        print("TIMES UP! Come back when you have fuel! Exiting Program!")
        sleep(1)
        exit()
        elseif turtle.getItemCount(16) == 2 then
        turtle.refuel(2)
        else print("ERROR!!")
    end
end

function refuel()
    if turtle.getFuelLevel() < 80 then
        print("Automatic refuel attempt.")
        sleep(2)
        autoRefuel()
    end
        if turtle.getFuelLevel() < 80 and autRefuel() == false then
            sleep(2)
            manRefuel()
        end
            if turtle.getFuelLevel() >= 80 then
                print("Fuel level is " ..turtle.getFuelLevel().. ".")
                print("No fuel needed!")
            end
end

function cutTree()
    turtle.select(1)
    print("Cutting down tree...")
    turtle.dig()
    turtle.forward()
    turtle.digDown()

    while turtle.detectUp() do
        turtle.digUp()
        turtle.up()
    end

    while true do
        if turtle.detectDown() then
            print("Done with tree...")
            break
        else
            turtle.down()
        end
    end
    turtle.back()
    turtle.select(1)
    turtle.place()
    print("Planting sapling...")
    turtle.digUp()
    turtle.up()
end
        refuel()
        turtle.select(1)
        print("Planting sapling...")
        turtle.place()
        turtle.digUp()
        turtle.up()

while true do
    if turtle.detect() then
        refuel()
        cutTree()
    else
        print("Waiting for tree to grow...")
        sleep(2)
    end
end