obsidian.lua

local fuelThreshold = turtle.getFuelLimit() / 2

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

local function selectItem(name)
    for i=15, 1, -1 do
        itemDetail = turtle.getItemDetail(i)
        if itemDetail and itemDetail.name == name then
            turtle.select(i)
            return true
        end
    end
    return false
end

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

local function waitForItem(name, amount)
    if countItem(name) < amount then
        print("Please provide more " .. name)
        while countItem(name) < amount do
            sleep(0.5)
        end
        print("Received sufficient " .. name .. ". Continuing...")
    end
    selectItem(name)
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 waitForDropUp()
    if turtle.getItemCount() > 0 and not turtle.dropUp() then
        print("Please make room for turtle to drop")
        while turtle.getItemCount() > 0 and not turtle.dropUp() do
            sleep(0.5)
        end
        print("Turtle successfully dropped. Continuing...")
    end
end

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

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

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

local function getItemName(slot)
    local itemDetail = turtle.getItemDetail(slot)
    if itemDetail then
        return itemDetail.name
    else
        return "minecraft:air"
    end
end

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

    if turtle.getFuelLevel() >= amount then
        return true
    elseif getItemName(1) == "minecraft:lava_bucket" then
        turtle.select(1)
        if not turtle.refuel(1) then
            return false
        end
    elseif getBlockUp() == "minecraft:lava_cauldron" then
        turtle.select(1)
        turtle.placeUp()
        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)
    refuel(fuelThreshold)
    while turtle.getFuelLevel() < amount do
        sleep(1)
        refuel(fuelThreshold)
    end
end

local function tryForward()
    waitForFuel(1)
    local success = turtle.forward()

    if getBlockDown() == "minecraft:obsidian" then
        turtle.digDown()
    end
    if not turtle.detectDown() then
        if getItemName(1) == "minecraft:lava_bucket" then
            refuel(fuelThreshold)
            if getItemName(1) == "minecraft:lava_bucket" then
                turtle.select(1)
                turtle.placeDown()
                if not turtle.detectDown() then
                    sleep(0.5)
                end
                turtle.digDown()
            end
        end
        if getBlockUp() == "minecraft:lava_cauldron" and getItemName(1) == "minecraft:bucket" then
            turtle.select(1)
            turtle.placeUp()
            refuel(fuelThreshold)
            if getItemName(1) == "minecraft:lava_bucket" then
                turtle.select(1)
                turtle.placeDown()
                if not turtle.detectDown() then
                    sleep(0.5)
                end
                turtle.digDown()
            end
        end
    elseif getBlockUp() == "minecraft:lava_cauldron" and getItemName(1) == "minecraft:bucket" then
        turtle.select(1)
        turtle.placeUp()
    end

    return success
end

local function repeatForward(amount)
    for i=1, amount do
        fastFail(tryForward())
    end
end

local function recenter()
    while getBlockDown() ~= "minecraft:barrel" do
        waitForFuel(1)
        if not turtle.forward() then
            turtle.turnLeft()
        end
    end
    while turtle.detect() do
        turtle.turnLeft()
    end
end

local function deposit()
    for i=2, 16 do
        if turtle.getItemCount(i) > 0 then
            turtle.select(i)
            waitForDropDown() -- Edit this line to when changing deposit direction
        end
    end
end

while true do
    recenter()
    deposit()

    for i=1, 10*60 do
        if getBlockUp() ~= "minecraft:lava_cauldron" then
            sleep(1)
        else
            break
        end
    end

    waitForFuel(1024)

    for i=0, 7 do
        if i == 0 then
            fastFail(tryForward())
        else
            fastFail(tryForward())
            turtle.turnRight()
        end
        repeatForward(14)
        turtle.turnLeft()
        fastFail(tryForward())
        turtle.turnLeft()
        repeatForward(14)
        if i ~= 7 then
            turtle.turnRight()
        end
    end
    fastFail(tryForward())
    turtle.turnLeft()
    repeatForward(15)
end