CC Bonemeal Optional Tree Cutter

-- definitions

local arg = { ... }
local log_name = "minecraft:birch_log"

function autoRefuel()
    if turtle.getFuelLevel() < 80 then
        turtle.select(16)
        while turtle.getFuelLevel() < 80 do
            turtle.refuel(1)
        end
        turtle.select(1)
    end
end

function autoBonemeal()
    n = turtle.getItemCount(14)
    turtle.select(14)
    for i=1,n do
        if not turtle.place() then break end
    end
end

-- turn left and suck
function LS()
    turtle.turnLeft()
    turtle.suck()
end

-- turn right and suck
function RS()
    turtle.turnRight()
    turtle.suck()
end

-- go forward and suck
function FS()
    turtle.forward()
    turtle.suck()
end

-- pick up the drops from the tree leaves
function getDrops()
    RS()
    LS()
    LS()
    FS()
    FS()
    LS()
    FS()
    LS()

    -- at bottom left corner facing right
    FS()
    FS()
    FS()
    FS()
    LS()

    -- at bottom right corner facing forward
    FS()
    FS()
    FS()
    FS()
    LS()

    -- at top right corner facing left
    FS()
    FS()
    FS()
    FS()
    LS()

    -- at top left corner facing back
    FS()
    LS()
    FS()
    FS()
    FS()
    RS()
    FS()
    FS()
    RS()
    FS()
    RS()

    -- back at start
end

--print("Enter number of trees to cut:")
--treesToCut = read()
if arg[1] then
    treesToCut = arg[1]
else
    treesToCut = 1
end

autoRefuel()

for i=1, treesToCut do

autoRefuel()

-- place sapling
turtle.select(15)
turtle.place()

autoBonemeal()

turtle.select(16)
crap, data = turtle.inspect()
while data.name ~= log_name do
    crap, data = turtle.inspect()
end

-- cut tree
while turtle.detect() do
    turtle.dig()
    turtle.digUp()
    turtle.up()
end

while not turtle.detectDown() do
    turtle.down()
end

turtle.select(15)
getDrops()

for j=1,12 do
    turtle.select(j)
    turtle.dropDown()
end

print(i, "/", treesToCut, " trees cut down.")

end

select(1)
print("Finished.")