I (26f) just received a text from my ex best friend (27f) after 3 years no contact, would a friendship now be possible?

I met my “ex best friend” (let’s call her Emily) during my first year of graduate school. We met on tinder and the first time we met was a “date”, we continued to talk but things never went anywhere romantically. I was interested but never got any indication that she was. I was okay with being friends, and we ended up being really close, talked every day, hung out at least once a week, went on a small road trip together, and would even go to the library to study together.

My second year of graduate school I met someone I was romantically involved with, and obviously told her about it. This is when things got really weird. Prior to me talking to my (now) ex, Emily would constantly bring up a guy she had a crush on or talk about how she missed her ex. I was supportive - encouraging her to talk to her crush. Then came the State Fair which was a 3 hour drive for me and Emily, my ex lived in the city the fair was happening. I mentioned to Emily that I wanted to go, and she said she was going with her family. I didn’t want to invite myself or just tag along so instead I asked my ex to meet me there and she said okay. I told Emily about it and that’s when things got really weird. Emily and I shared locations with each other and I had left maybe an hour or two before she did, and was already at the fair before she got there. I saw she was in the same general area as me when I got the text “Goodbye”. No other context no reply. I texted her several times and nothing. I gave her space and reached out again maybe two weeks later, still nothing.

During all of this I got hurt. I came to realize that I actually had feelings for Emily and wanted something more. It felt like unrequited love. I spiraled, started drinking a lot more and would occasionally send her dumb drunk texts. Those also never got any response.

So after about 6 months of no contact - I deleted her number to avoid any other drunk texts. I started deleting the texts and pictures we had together as well. We ran into each other a few times in the small college town but never talked. That’s when I just accepted the fact we probably never would.

3 years of no contact from her and on Saturday she completely texted me out of nowhere. It was 4 am. I responded a little later and it was like old times - felt like we picked up right where we left off.

I don’t know what to think of all of this. Would you be friends in this situation? Would you even let someone back in?