Your friend is obviously disturbed. I only have the information from your post but it sounds like he is capable of hurting those around him ("you will be beaten with a baseball bat"). Since he is unwilling to receive help of any kind there is really nothing you can do.
The first issue that he needs to address is his cocaine addiction. A common feeling that cocaine users get is a feeling that they can do anything (supposedly Hitler was a cocaine user and was on the stuff when he decided to invade Russia).
I'm gonna guess that he had some issues to begin with that became exacerbated by the chemical effects of coke.
The common advice, and it is good advice, for drug addicts who refuse all help is that all those close to them cut off all contact. One of the reasons for this is the fewer consequences the addict has to deal with the less reason he has to stop using.
I have 15 years clean from cocaine use and have too many experiences with friends who were very heavy drug addicts.
The only advice I can give you based on my own experiences is that you tell him that you love him and that you are worried about him. That you want to help him and want him to get help. That if he won't seek help that you can't remain in his life though you will always be his friend and he can always come to you if he wants to get the help he needs.
I'm not a doctor or a professional in these matters though so who knows.
I would suggest you talk to your own doctor and ask him for his thoughts.
The thing that concerns me most is his threat to his roommate. Your friend might be VERY dangerous to others let alone himself. This is a situation of which I have no experience whatsoever.
Again, I would talk to your physician about this.
As for you I suggest maybe going to an
Alanon meeting.
Alanon is a group for people who have or have been in close relationships with drug addicts/alcoholics. You will almost assuredly find someone there who has had either your experience or one very similar. IMHO it would be a good idea to talk to these people and ask them for advice and help. You might find some answer as to how to deal with this situation.
I have much empathy for you.
Hope this helps. Good luck to you.