TurtleTree

SaplingSlot = 1
BoneSlot = 2
WoodSlot = 3
FlintSlot = 16
EdgeDistance = 4

-- SaplingSide = "right"
-- BoneSide = "back"
-- DropSide = "right"
-- FlintSide = "left"

function EnsureSaplingPlaced()
    if not turtle.detect() then
        turtle.select(SaplingSlot)
    end
    turtle.place()
end

function Fertilize()
    turtle.select(BoneSlot)
    turtle.place()
end

function CheckGrown()
    if turtle.detectUp() then
        turtle.digUp()
    end
    turtle.up()
    local detected = turtle.detect()
    turtle.down()
    return detected
end

function IsEmpty(slot)
    local last = turtle.getSelectedSlot()
    turtle.select(slot)
    local empty = turtle.getItemCount() <= 0
    turtle.select(last)
end

function EnsureHasSapling()
    local hasBonemeal = not IsEmpty(BoneSlot)
    turtle.select(SaplingSlot)
    turtle.turnRight()
    turtle.suck()
    FlushExcessSaplings(hasBonemeal)
    turtle.turnLeft()
end

function FlushExcessSaplings(hasBonemeal)
    for i=1,16,1 do
        turtle.select(i)
        if i ~= SaplingSlot and not (hasBonemeal and i == BoneSlot) and not IsFlintAndSteel(i) then
            turtle.drop()
        end
    end
end

function EnsureHasBonemeal()
    turtle.select(BoneSlot)
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.suck()
    FlushExcessBonemeal()
    turtle.turnLeft()
    turtle.turnLeft()
end

function FlushExcessBonemeal()
    for i=1,16,1 do
        if i ~= SaplingSlot and i ~= BoneSlot and not IsFlintAndSteel(i) then
            turtle.select(i)
            turtle.drop()
        end
    end
end

function IsFlintAndSteel(slot)
    local data = turtle.getItemDetail(slot)
    if data == nil then
        return false
    end

    local id = data.name
    return id == "minecraft:flint_and_steel"
end

function HasFlintAndSteel()
    return not IsEmpty(FlintSlot) and IsFlintAndSteel(FlintSlot)
end

function EnsureFlintAndSteel()
    if not HasFlintAndSteel() then
        turtle.turnLeft()
        turtle.select(FlintSlot)
        turtle.suck()
        turtle.turnRight()
    end
end

function FellTree()
    turtle.select(WoodSlot)
    turtle.dig()
    turtle.forward()

    while turtle.detectUp() do
        turtle.digUp()
        turtle.up()
    end
    os.sleep(2)

    local needsBurn = false
    local last = turtle.getSelectedSlot()
    turtle.select(FlintSlot)
    while not turtle.detectDown() do
        if needsBurn then
            turtle.placeUp()
        end

        needsBurn = turtle.detect()
        turtle.down()
    end
    turtle.select(last)

    turtle.back()
end

function DropProduce()
    turtle.turnRight()
    for i=1,16,1 do
        if i ~= BoneSlot and i ~= SaplingSlot and i ~= FlintSlot then
            turtle.select(i)
            turtle.drop()
        end
    end
    turtle.turnLeft()
end

function GoToRefillPos()
    for i=1,EdgeDistance,1 do
        turtle.back()
    end
end

function GoToGrowPos()
    for i=1,EdgeDistance,1 do
        turtle.forward()
    end
end

while true do
    print("-- Ensuring Saplings")
    EnsureHasSapling()
    print("-- Ensuring Bonemeal")
    EnsureHasBonemeal()
    print("-- Ensuring Flint and Steel")
    EnsureFlintAndSteel()
    print("-- Moving to GrowPos")
    GoToGrowPos()
    print("-- Placing Sapling")
    EnsureSaplingPlaced()

    print("-- Start Fertilize-Loop")
    while not CheckGrown() do
        Fertilize()
    end
    print("-- Felling Tree")
    FellTree()
    print("-- Moving to RefillPos")
    GoToRefillPos()
    print("-- Dropping Produce")
    print("-- Cycle done.")
    print("")
    DropProduce()

    os.sleep(1)
end