Chopper_no_bm_v2

local function checkFuel()
    if turtle.getFuelLevel() < 1 then
        turtle.select(2)
        turtle.refuel(1)
    end
end

-- Move Functions
local function Up()
    checkFuel()
    turtle.up()
end

local function Down()
    checkFuel()
    turtle.down()
end

local function Forward()
    checkFuel()
    if turtle.forward() then
        return true
    end
end

local function Back()
    checkFuel()
    turtle.back()
end

local function Right()
    turtle.turnRight()
end

local function Left()
    turtle.turnLeft()
end

local function Turn()
    turtle.turnLeft()
    turtle.turnLeft()
end

local function Start()
    turtle.dig()
    Forward()
end

local function FellUp()
    up = 0
    while turtle.detectUp() do
        turtle.dig()
        turtle.digUp()
        Up()
        up = up + 1
    end
end

local function Move()
    turtle.dig()
    Right()
    turtle.dig()
    Forward()
    Left()
end

local function FellDown()
    while up > 0 do
        turtle.dig()
        turtle.digDown()
        Down()
        up = up - 1
    end
    turtle.dig()
end

local function Place()
    turtle.select(1)
    turtle.placeDown()
end
local function Plant()
    Up()
    Place()
    Forward()
    Place()
    Left()
    Forward()
    Place()
    Left()
    Forward()
    Place()
    Forward()
    Down()
end

local function GetSap()
    NeedSap = 64 - turtle.getItemCount(1) -- How many
    Left()
    turtle.select(1)
    turtle.suck(NeedSap)
end

local function Drop()
    Turn()
    for i = 3,16 do
        turtle.select(i)
        turtle.drop()
    end
    Drop2 = turtle.getItemCount(2) - 5 -- Keeps 5 wood as fuel
    if Drop2 < 0 then
        Drop2 = 0
    end
    turtle.select(2)
    turtle.drop(Drop2)
 Right()
end

local function CheckTree()
    turtle.select(1)
    while turtle.compare() do
    sleep(0.5)
    end
end

local function CheckSap()
    if turtle.getItemCount(1) < 5 then
        print "Not enough saplings"
        while turtle.getItemCount(1) < 5 do
            sleep(0.5)
        end
        print "\nResuming"
    end
end

while true do
    CheckSap()
    CheckTree() -- Freezes the program until a tree is detected
    Start()
    FellUp()
    Move()
    FellDown()
    Plant()
    GetSap()
    Drop()
end