Bukkit

Is there any way to make it conditional based on what Block/Item the player has in hand (whitelist would be ideal in this situation, instead of blacklist, but both being available)? On top of that, the ability to assign a specific permission to each, and a bypass?

For example, I've long wanted just a simple plugin that lets me let players use /hat but not just use any block or item like currently is possible.
In this case it'd be something like how BetterAlias works (or at least how it's config is laid out):

hat:                                          #See Note1
   permission: anticommands.hat.1             #See Note2
   whitelist: DIAMOND_BLOCK, DIAMOND_ORE,     #See Note3
              WOOL:2, WOOL:3, BANNER:*        #See Note4
   condition: [hand, inventory, head,         #See Note5
               torso, legs, feet, any,
               hotbar1, hotbar2, etc]

Note1: This is the command.
Note2: This is the permission node. The .1 is to indicate this specific conditional, where .2 would have it's own whitelist or blacklist.
Note3: These are IDs of what must be in hand in order to run the command for the player. If they are holding _anything_ else, it won't execute. If they lack the above permission, it won't execute.
Note4: I'm assuming BANNER.* will allow for any banner to be worn, figuring when customized they are sorta like Potions with their Data Values.
Note5: This specifies where on a player the white/black listed ID/s would need to be, in order to execute the command. "any" would thus mean anywhere on the player, armor, hotbar, or inventory.

Bypass Perm would be, in this instance: anticommand.hat.*.bypass or anticommand.hat.bypass (I understand that hat.*. in this case accomplishes the same thing as hat.bypass, but I'm just anticipating a situation it'd come in handy that I'm not considering right now)

Heck, may not even really need to program any permission function directly, and just hook into Vault instead, which would be completely fine by me :D

I think being able to limit, but specify the conditions that need to be met in order to execute. Which a number of situations I can think of where this could offer me more flexibility on my RPG server. Furthering the above's possible use would be the ability to make the item/block have an NBT conditional... Item name that matches, or lore.

Which in our specific case would need to not be too anal about matching. For example our one weapons plugin outputs names which are a bit stupid. They look fine, but when you look at the NBT is where things show up. We see "&6&lBig Sword", but NBT has "&0&0&0&0&0&0&0&f&b&6&lBig Sword" :\ So the conditional would for instance be to match anywhere in the indicated line (Name, Lore), but still the specific string in the config. Using the Big Sword example, in the config we'd have "&6&lBig Sword", so an anvil named item wouldn't work since it'd be "&b&oBig Sword". However, all those &0s and silliness would be ignored.
(It's an old, abandoned plugin that is core to our server, but otherwise works fine besides a hiccup here and there, such as that)

Thanks :)
-Form

(apologies is this would've been better suited as a Ticket...)