lavarefuel2

local FUEL_THRESHOLD = turtle.getFuelLimit() - 100 --15000
local BUCKET = "minecraft:bucket"
local LAVA = "minecraft:lava"

---@param name string
---@return boolean exists
---@return number slot
local function hasItem(name)
    for slot = 1, 16 do
        local info = turtle.getItemDetail(slot)

        if info and info.name == name then
            return true, slot
        end
    end

    return false, 1
end

assert(hasItem(BUCKET), "Missing bucket!")

local function drillRefuel()
    local y = 0

    while true do
        local exists, info = turtle.inspectDown()

        if not exists or info.name ~= LAVA or info.state.level ~= 0 then
            break
        end

        turtle.placeDown()
        turtle.refuel(1)
        turtle.down()

        y = y + 1
    end

    for _ = 1, y do
        turtle.digUp()
        turtle.up()
    end
end

local i = 0

while true do
    drillRefuel()

    if turtle.getFuelLevel() >= FUEL_THRESHOLD then
        break
    end

    repeat
        turtle.dig()
    until turtle.forward()

    i = i + 1
end

for _ = 1, i do
    turtle.back()
end