Anyone know if there is a way to conditionally switch to a different paladin seal via a macro?

For druids, for example, you can do something like this:

/cast [nostance:5]Moonkin Form; Wrath

That would throw you into moonkin form if you aren't in it and cast Wrath if you are in moonkin.

I'm trying to figure out something like that for seals if such a thing exists, but haven't been able to find it. Seals aren't buffs, strictly speaking, any more, nor do they seem to be auras or anything else obvious.

Ideally I would use this macro as a preface to handle different types of fights - have it put on seal of truth if I'm spamming my single-target key, seal of righteousness if I'm doing AOE, and seal of insight if I'm casting spells.