Tree Felling

posY = 0
gotFuel = 1

function turtle.forwards(numForw)
    for i = 1, numForw do
        turtle.forward()
    end
end

function farmPath1()
    turtle.turnRight()
    turtle.forward()
    turtle.turnLeft()
    turtle.forwards(5)
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
end

function farmPath2()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
    turtle.forwards(2)
    turtle.turnLeft()
    turtle.forwards(4)
    turtle.turnLeft()
end

function turtle.turns180()
    for i = 1, 2 do
        turtle.turnRight()
    end
end

function emptyBirchLogs()

    for i = 1, 16 do
        turtle.select(i)
        if turtle.getItemCount() ~= 0 then

            local data = turtle.getItemDetail()

            if data.name == "minecraft:birch_log" then
                turtle.drop()
            end
        end
    end
end

function refuel()
    turtle.select(1)
    if turtle.getFuelLevel() <= 100 then
        turtle.turnRight()
        turtle.forward()
        turtle.turnRight()
        turtle.suck()
        turtle.refuel(64)
        if turtle.getFuelLevel() <=100 then
            gotFuel = 0
        end
        turtle.turnRight()
        turtle.forward()
        turtle.turnRight()
     end
end

function suck()
    turtle.turnLeft()
    turtle.forwards(2)
    turtle.turnRight()
    turtle.forwards(14)
    turtle.turnLeft()
    turtle.suckDown()
    turtle.forward()
    turtle.suckDown()
    turtle.turnLeft()
    turtle.forwards(15)
    turtle.turnLeft()
    turtle.suckDown()
    turtle.forward()
    turtle.suckDown()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
    turtle.forwards(2)
    turtle.turnLeft()
end

function emptyBirchSaplings()

    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    for i = 1, 16 do
        turtle.select(i)
        if turtle.getItemCount() ~= 0 then

            local data = turtle.getItemDetail()

            if data.name == "minecraft:birch_sapling" then
                turtle.drop()
            end
        end
    end
    turtle.select(13)
    turtle.suck(10)
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
end

function emptySticks()

    turtle.turnRight()
    turtle.forwards(2)
    turtle.turnRight()
    for i = 1, 16 do
        turtle.select(i)
        if turtle.getItemCount() ~= 0 then

            local data = turtle.getItemDetail()

            if data.name == "minecraft:stick" then
                turtle.drop()
            end
        end
    end
    turtle.turnRight()
    turtle.forwards(2)
    turtle.turnRight()
end

function fellTree()
    local block, type = turtle.inspect()

        if type.name == "minecraft:birch_log" then
            turtle.dig()
            turtle.forward()
                        while turtle.detectUp() do
                            turtle.digUp()
                            turtle.up()
                            posY = posY +1;
                        end
                for i = 1, posY do
                    turtle.down()
                    posY = posY -1;
                end
                turtle.back()
                turtle.select(13)
                turtle.place()
                turtle.select(1)
        end
end

while gotFuel == 1 do
    os.sleep(600)
    refuel()
    if turtle.getFuelLevel() > 100 then
    turtle.select(1)
    fellTree()
    farmPath1()
    fellTree()
    farmPath1()
    fellTree()
    farmPath2()
    fellTree()
    farmPath1()
    fellTree()
    farmPath1()
    fellTree()
    farmPath2()
    turtle.turns180()
    emptyBirchLogs()
    turtle.turns180()
    suck()
    emptyBirchSaplings()
    emptySticks()
    else
        gotFuel = 0
    end
end