Single/multishot firing based on mouse button press

So i’ve created a really basic shooting system that works for when you want to shoot multiple bullets, but it doesn’t work when you try to shoot single shots. What I mean is, that when you press the mouse button once, it should shoot a single bullet, otherwise, the mouse button is held down, so it should keep shooting bullets. I can’t figure out how to make the single shot possible.

Have it shoot on a time interval (say one bullet every 0.1 seconds). If the player doesn’t click that fast then have a delay after, or just before, the very first shot.