Our friend comes over and is disrespectful and brings weed and alcohol

I do not smoke anymore, I used to before I had my son, but I'm past it for myself and so is my husband.

   Our friend on the other hand, I'm beyond fed up with. First of all, he texts us all day every day, he asks every. Single. Day. If he can come over and I say yes once a week. Why is it he feels he can stop by after I say no other days? I have addressed him about it. He still does it. My husband is next (I'm more assertive lol) 

   On top of him stopping by, he comes over with weed and alcohol every time and asks us 50 times if we want to, no. I've also told him to stop bringing it over and if he does smoke he isn't to be playing with my son. Mainly because I won't even have a glass of wine if our 23 month old is awake let alone let someone else that is so high, eyes glazed, play with him...that's just my parenting preference, I don't think it's too crazy. No mind-altering substances around my child; even if I do realize th amazing benefits.

 He told me he is really depressed and hates being alone and feels he doesn't matter... I've tried being a good friend but I can't keep being disrespected in my own home especially with my views...

Am I overreacting? 

Also, I'm not bashing anyone that smokes and has children. That's not my intention. I just don't like it in my home...