args = {...}
local distance = tonumber(args[1])
local fuelSlot = 15
local torchSlot = 16

function refuel()
    while turtle.getFuelLevel() < 1000 do
        term.clear()
        print("This computer is running out of Fuel")
        print("Looking for fuel in slot 15")
        turtle.select(fuelSlot)
        turtle.refuel()
        turtle.select(1)
        -- Fuel up
        -- Include message when computer can't find fuel
        os.sleep(1)
    end
end

function placeTorch()
    turtle.select(16)
    turtle.placeDown()
end

function digForward()
    refuel()
    turtle.select(1)
    while not turtle.forward() do
        turtle.dig()
    end
end

function digBackward()
    refuel()
    turtle.select(1)
    for i=1,2 do
        turtle.turnLeft()
    end
    while not turtle.forward() do
        turtle.dig()
    end
end

function digUp()
    refuel()
    turtle.select(1)
    turtle.digUp()
end

function digDown()
    refuel()
    turtle.select(1)
    turtle.digDown()
end

function digLeft()
    refuel()
    turtle.select(1)
    turtle.turnLeft()
    while not turtle.forward() do
        turtle.dig()
    end
end

function digRight()
    refuel()
    turtle.select(1)
    turtle.turnRight()
    while not turtle.forward() do
        turtle.dig()
    end
end

function digLine(direction)
    if direction == "right" then
        digForward()
        turtle.turnRight()
        for i=1,2 do
            digUp()
            digDown()
            digForward()
        end
        digUp()
        digDown()
        turtle.turnLeft()


    elseif direction == "left" then
        digForward()
        turtle.turnLeft()
        for i=1,2 do
            digUp()
            digDown()
            digForward()
        end
        digUp()
        digDown()
        turtle.turnRight()
    end
end

turtle.select(1)


if #args == 0 then
    distance = 1
end

local j = 0
for i=1,distance do
    digLine("right")
    if j % 4 == 0 then
        placeTorch()
    end
    digLine("left")
    j = j + 1
end