Setting a weak aura up for a Outlaw Single buff SiF Rules.

[ThatShadyGuy]

What I am trying to encapsulate in 2 weakauras right now are the rules regarding rolling a single roll of Shark infested waters.

The rules are these,

1) If Adrenaline rush and Curse of the dreadblades are not available, Do not keep the single roll of Shark Infested Waters.
2) If Adrenaline rush and Curse of the dreadblades are available, keep the single roll of Shark Infested Waters.
3) If Curse of the dreadblades has 15 seconds or less on it's cooldown, keep the single roll of Shark Infested Waters.

I already have the first rule set up as Don't Keep which works fine, the same thing with the second rule which I have under Keep.

My current issue right now is I'm kind of stumped on creating the instance on the third rule. Is this doable using the options given to you in Weak auras? or do I have to go into the Custom Text Editor and create the instance myself using LUA