timber

-- pastebin.com/nNgb6mcy

local WAIT_TIME = 5 -- time to wait to check if tree has grown
local SAPLING_SLOT = 16
local FUEL_SLOT = 1
local DUMP_INTO_CHEST = true
local WAITING_MESSAGE = "Waiting for tree to grow..."

term.clear()
term.setCursorPos(1,1)

print(WAITING_MESSAGE)

function fuelCheck()
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel < 80 then
        turtle.select(FUEL_SLOT)
        turtle.refuel(1)
        print("Refueled!")
    end
end

function chopUp()
    turtle.digUp()
    turtle.dig()
    turtle.up()
    turtle.dig()
end

function chopDown()
    turtle.digDown()
    turtle.dig()
    turtle.down()
end

function changeSide()
    turtle.turnLeft()
    turtle.dig()
    turtle.forward()
    turtle.turnRight()
end

function plantSaplings()
    turtle.select(SAPLING_SLOT)
    turtle.place()
    turtle.turnLeft()
    turtle.back()
    turtle.place()
    turtle.turnRight()
    turtle.place()
    turtle.back()
    turtle.place()
end

function dump()
    print("Dumping in chest below!")
    for i = 2, 15 do
        turtle.select(i)
        turtle.dropDown()
    end
    turtle.select(SAPLING_SLOT)
end

function checkTree()
    local success, data = turtle.inspect()
    if success and data.tags["minecraft:logs"] == true then
        print("Tree has grown!")
        fuelCheck()
        chopTree()
    else
        os.sleep(WAIT_TIME)
    end
end

function chopTree()
    turtle.select(SAPLING_SLOT)
    turtle.dig()
    turtle.forward()
    local success, dataUp = turtle.inspectUp()
    if not success then
        turtle.back()
        error("\n****\nNo Tree to fell!\n****\n")
    end
    while dataUp.tags["minecraft:logs"] == true do
        chopUp()
        success, dataUp = turtle.inspectUp()
        if not success then
            chopUp()
            break
        end
    end
    chopUp()
    changeSide()
    chopUp()
    while turtle.detectDown() == false do
        turtle.down()
    end
    local success, dataDown = turtle.inspectDown()
    if not success then
        error()
    end
    while dataDown.tags["minecraft:logs"] == true do
        chopDown()
        success, dataDown = turtle.inspectDown()
        if not success then
            break
        end
    end
    turtle.dig()
    plantSaplings()
    if DUMP_INTO_CHEST == true then
        dump()
        print("Dumped items!")
    end
    print(WAITING_MESSAGE)
end


while true do
    checkTree()
end