add: unique session generation

main.py

@@ -16,8 +16,22 @@ cur = con.cursor()  # NB! single is enough for now, we might require multiple la
 async def new_session():
     """Start a new session"""
     # add session to the database
+    try:
+            # generate a cookie
+            cookie = uuid4().hex
+            cur.execute(
+                """INSERT INTO sessions(cookie)
+                            VALUES(:cookie)
+                        """,
+                {"cookie": cookie},
+            )
+            con.commit()
+        except sqlite3.IntegrityError as e:
+            if str(e) == "UNIQUE constraint failed: sessions.cookie":
+                return {"cookie": "error"}
+
     # return new session cookie
-    return {"session_id": 42}
+    return {"cookie": cookie}
 
 
 @app.get("/next_picture/{cookie}")