create function to get all months of line items in string form

app/utils.py

@@ -1,9 +1,12 @@
 import os
 import datetime
 import calendar
+from app import db
+from sqlalchemy import select, delete, update, distinct
+from .models import LineItem, BudgetCategory, Vendor
+
 
 def get_month_timestamps(month:int, year:int) -> tuple[float, float]:
-    print(month, year)
     # Get the first day of the requested month and subtract one day to get the last day of the previous month
     first_day_of_requested_month = datetime.datetime(year, month, 1)
     last_day_of_requested_month = first_day_of_requested_month + datetime.timedelta(days=calendar.monthrange(year, month)[1] - 1) 
@@ -20,4 +23,13 @@ def get_uploads_path() -> str:
         if os.path.exists(p):
             path = p
             break
-    return path
+    return path
+
+def get_all_months():
+    lis = [datetime.datetime.fromtimestamp(int(s)) for s in db.session.execute(select(distinct(LineItem.date))).scalars().all()]
+    month_year = {(s.month, s.year) for s in lis}
+    
+    month_year = [datetime.datetime(year=x[1], month=x[0], day=1) for x in month_year]
+    month_year.sort(reverse=True)
+    return [x.strftime("%b %Y") for x in month_year]
+