import

local tool = {}
local t = turtle

function tool.needR(slotMax)
    slot = t.getSelectedSlot()
    if not slotMax then
        slotMax = 16
    end
    t.select(1)
    if turtle.getFuelLevel()<10 then
        while not turtle.refuel(1) do
            turtle.select((turtle.getSelectedSlot()%slotMax)+1)
        end
    end
    t.select(slot)

end


function tool.checkGravel()
    _, tuple = t.inspectUp()
    if not tuple then return end
    while string.find(tuple.name, 'gravel') do
        t.dig()
        _, tuple = t.inspectUp()
        if not tuple then break end
    end
end

function tool.fd(slotMax)
    tool.needR(slotMax)
    b, tuple = turtle.inspect()
    if b then
        if string.find(tuple['name'], 'lava') then
            return
        end
    end
    while not t.forward() do t.dig() end
end

function tool.d()
    tool.needR()
    b, tuple = turtle.inspectDown()
    if b then
        if string.find(tuple['name'], 'lava') then
            return
        end
    end
    while not t.down() do t.digDown() end
end

function tool.up()
    tool.needR()
    b, tuple = turtle.inspectUp()
    if b then
        if string.find(tuple['name'], 'lava') then
            return
        end
    end
    while not t.up() do t.digUp() end
end




return tool