Dumbledore is a matured INTP. This is clear if you’ve read all the books. He’s an NT temperament and an introverted (Enneagram) 5: private, secretive, often detached, very clever and only tells his “pieces”, including Harry, what he’s up to on a need-to-know basis. He’s not a J, either; compare him to J characters like Hermoine, Snape and McGonnegal, he’s nothing like that; for one thing, he doesn’t hesitate to bend rules to fit the cirumstances. He’s much more flexible.
Dumbledore vs. Voldemort is a classic NTP vs. NTJ matchup.