It will be very hard to accomplish.
It will not make it easier to the eventer (the user, you). Quite to the contrary. It will make it harder.
You would want to take spelling errors and weird phrases into account.
You would have to analyze the input and 'understand' it so that you can give a corresponding response.
Just look at the various bots you can talk to. I have seen none that I think are satisfactory (imo)
Of course you can limit the area that the NPC have to understand, but even so it will be very difficult to make unless do to the keyword combination. ('Take Key', 'Say Hello', etc.)
There are also issue for the 'eventer'.
You would probably like the characters to respond differently as well as allowing to specify what they know.
It's obvious that they will have a lot more information than normally. You will have to specify that. You will have to fill in that information.
I don't think anyone will make it, but I wish you good luck regardless
*hugs*