treefarm.lua

local xpos = -1
local ypos = -1
local zpos = -1
local dir = -1

local function fastFail(success)
    if not success then
        print("An unexpected error has occured! Aborting.")
        exit()
    end
end

local function refuel(amount)
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" then
        return true
    end

    turtle.select(16)
    while turtle.getItemCount(16) > 0 and turtle.getFuelLevel() < amount do
        if not turtle.refuel(1) then
            return false
        end
    end

    if turtle.getFuelLevel() < amount then
        return false
    else
        return true
    end
end

local function waitForFuel(amount)
    if not refuel(amount) then
        print("Please put fuel in slot 16")
        while not refuel(amount) do
            sleep(0.5)
        end
        print("Received sufficient fuel. Continuing...")
    end
end

local function selectSapling()
    for i=1, 15 do
        itemDetail = turtle.getItemDetail(i)
        if itemDetail and itemDetail.name == "terrestria:hemlock_sapling" then
            turtle.select(i)
            return true
        end
    end
    return false
end

local function countSaplings()
    num = 0
    for i=1, 15 do
        itemDetail = turtle.getItemDetail(i)
        if itemDetail and itemDetail.name == "terrestria:hemlock_sapling" then
            num = num + itemDetail.count
        end
    end
    return num
end

local function waitForSapling(amount)
    if countSaplings() < amount then
        print("Please provide more hemlock saplings")
        while countSaplings() < amount do
            sleep(0.5)
        end
        print("Received saplings. Continuing...")
    end
    selectSapling()
end

local function waitForDrop()
    if turtle.getItemCount() > 0 and not turtle.drop() then
        print("Please make room for turtle to drop")
        while turtle.getItemCount() > 0 and not turtle.drop() do
            sleep(0.5)
        end
        print("Turtle successfully dropped. Continuing...")
    end
end

local function waitForDropDown()
    if turtle.getItemCount() > 0 and not turtle.dropDown() then
        print("Please make room for turtle to drop")
        while turtle.getItemCount() > 0 and not turtle.dropDown() do
            sleep(0.5)
        end
        print("Turtle successfully dropped. Continuing...")
    end
end

local function getBlock()
    hasBlock, data = turtle.inspect()
    if hasBlock then
        return data.name
    else
        return "minecraft:air"
    end
end

local function getBlockDown()
    hasBlock, data = turtle.inspectDown()
    if hasBlock then
        return data.name
    else
        return "minecraft:air"
    end
end

local function getBlockUp()
    hasBlock, data = turtle.inspectUp()
    if hasBlock then
        return data.name
    else
        return "minecraft:air"
    end
end

local function isImpermeable(name)
    if name == "minecraft:stone_bricks" or name == "minecraft:dirt" or name == "minecraft:chest" or name == "minecraft:barrel" then
        return true
    else
        return false
    end
end

local function tryForwards()
    waitForFuel(1)
    -- if not turtle.detect() then
    --     turtle.suck()
    -- end
    while not turtle.forward() do
        if isImpermeable(getBlock()) then
            return false
        end
        if turtle.detect() then
            if not turtle.dig() then
                return false
            end
        elseif not turtle.attack() then
            sleep(0.5)
        end
    end

    if dir == 0 then
        xpos = xpos + 1
    elseif dir == 1 then
        zpos = zpos + 1
    elseif dir == 2 then
        xpos = xpos - 1
    elseif dir == 3 then
        zpos = zpos - 1
    end

    return true
end

local function tryDown()
    -- if not turtle.detectDown() then
    --     turtle.suckDown()
    -- end
    waitForFuel(1)
    while not turtle.down() do
        if isImpermeable(getBlockDown()) then
            return false
        end
        if turtle.detectDown() then
            if not turtle.digDown() then
                return false
            end
        elseif not turtle.attackDown() then
            sleep(0.5)
        end
    end

    if dir >= 0 then
        ypos = ypos - 1
    end

    return true
end

local function tryUp()
    -- if not turtle.detectUp() then
    --     turtle.suckUp()
    -- end
    waitForFuel(1)
    while not turtle.up() do
        if isImpermeable(getBlockUp()) then
            return false
        end
        if turtle.detectUp() then
            if not turtle.digUp() then
                return false
            end
        elseif not turtle.attackUp() then
            sleep(0.5)
        end
    end

    if dir >= 0 then
        ypos = ypos + 1
    end

    return true
end

local function turnLeft()
    -- if not turtle.detect() then
    --     turtle.suck()
    -- end
    turtle.turnLeft()
    dir = (dir + 1) % 4
end

local function turnRight()
    -- if not turtle.detect() then
    --     turtle.suck()
    -- end
    turtle.turnRight()
    dir = (dir + 3) % 4
end

local function recenter()
    waitForFuel(128)

    while not isImpermeable(getBlockDown()) do
        tryDown()
    end

    while getBlockDown() ~= "minecraft:chest" do
        if not tryForwards() then
            turtle.turnLeft()
        end
    end

    while getBlock() ~= "minecraft:barrel" do
        turtle.turnLeft()
    end

    xpos = 2
    zpos = 0
    ypos = 0
    dir = 0
end

recenter()

while true do
    -- Refuel
    turtle.select(16)
    waitForDrop()
    turtle.suck()
    if not refuel(1024) then
        print("Waiting for fuel...")
        sleep(0.5)
        while not refuel(1024) do
            sleep(0.5)
            waitForDrop()
            turtle.suck()
        end
    end

    turnLeft()

    while getBlock() == "terrestria:hemlock_sapling" do
        sleep(0.5)
    end

    fastFail(tryForwards())
    turnRight()

    for i=0, 63 do
        if turtle.detectUp() then
            for j=0, 3 do
                turtle.dig()
                turnRight()
                turtle.dig()
                turnRight()
                turnRight()
                fastFail(tryForwards())
            end
        end
        if i ~= 63 then
            fastFail(tryUp())
        end
    end

    for i=0, 61 do
        fastFail(tryDown())
    end

    waitForSapling(4)
    for j=0, 3 do
        turnLeft()
        fastFail(tryForwards())
        waitForSapling(1)
        turtle.placeDown()
    end
    turnRight()
    fastFail(tryForwards())
    turnLeft()
    fastFail(tryDown())

    for i=1, 15 do
        itemDetail = turtle.getItemDetail(i)
        if itemDetail and itemDetail.name ~= "terrestria:hemlock_sapling" then
            turtle.select(i)
            waitForDropDown()
        end
    end

    for i=1, 12 do
        itemDetail = turtle.getItemDetail(i)
        if itemDetail and itemDetail.name == "terrestria:hemlock_sapling" then
            turtle.select(i)
            turtle.transferTo(13)
            turtle.transferTo(14)
            turtle.transferTo(15)
            waitForDropDown()
        end
    end

    turtle.select(16)
    if not turtle.refuel(0) then
        waitForDropDown()
    end
end