local tArgs = {...}


local length = tonumber(tArgs[1])
local width = tonumber(tArgs[2])


function checkFuel()
    if turtle.getFuelLevel() <= 100 then
        if turtle.getItemCount(1) == 0 then
            print("Out of fuel.")
            exit()
        else
            turtle.select(1)
            turtle.refuel(1)
        end --if
    end --if
end --checkFuel()


function tunnel(givenLength)


  for index = 1,givenLength do
        while turtle.detectUp() do
            turtle.digUp()
            sleep(0.25)
        end

        while not turtle.forward() do
            turtle.dig()
        end
        while turtle.detectUp() do
            turtle.digUp()
            sleep(0.25)
        end

    end --for

    turtle.turnRight()
    turtle.dig()
    turtle.forward()
    turtle.turnRight()
    for index = 1,givenLength do
        while turtle.detectUp() do
            turtle.digUp()
                sleep(0.25)
        end

        while not turtle.forward() do
            turtle.dig()
        end
         while turtle.detectUp() do
            turtle.digUp()
            sleep(0.25)
        end

    end --for

end --tunnel()


-- MAIN

for index = 1, width  do
    checkFuel()
    tunnel(length)
    turtle.turnLeft()
    turtle.dig()
    turtle.forward()
    turtle.turnLeft()
end

-- return to starting postition
checkFuel()
turtle.turnLeft()
for index = 1,width*2 do
    while not turtle.forward() do
        turtle.dig()
    end
end