Rework the detailed provided for the issue stats

Basically, we want to know the trend of open tickets, so we take
the current number of tickets and for each week we remove from this
number the number of opened tickets and add the closed tickets (which
were thus still open at the beginning of the week).

We also only want to ignore closed tickets without a closed_at date
if they are in the window of tickets we're looking at (a year). So
if the most recent ticket without a closed_at date is older than a
year, then we assume that all the tickets have a closed_at date and
move on.

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>

pagure/lib/query.py

@@ -5660,19 +5660,40 @@ def issues_history_stats(session, project, detailed=False):
     :arg repo: model.Project object to get the issues stats about
 
     """
-
-    # Some ticket got imported as closed but without a closed_at date, so
-    # let's ignore them all
-    to_ignore = (
+    tomorrow = datetime.datetime.utcnow() + datetime.timedelta(days=1)
+    current_open = (
         session.query(model.Issue)
         .filter(model.Issue.project_id == project.id)
-        .filter(model.Issue.closed_at == None)  # noqa
-        .filter(model.Issue.status == "Closed")
+        .filter(model.Issue.status == "Open")
         .count()
     )
 
+    # Check if the oldest ticket with a closed_at date is older than a year
+    # ago, if it is, we will assume that all tickets that were closed last year
+    # have a closed_at date set.
+    oldest_closed = (
+        session.query(model.Issue)
+        .filter(model.Issue.project_id == project.id)
+        .filter(model.Issue.closed_at != None)  # noqa
+        .order_by(sqlalchemy.asc(model.Issue.closed_at))
+        .first()
+    )
+    a_year_ago = tomorrow - datetime.timedelta(days=(53 * 7))
+    if oldest_closed and oldest_closed.closed_at < a_year_ago:
+        to_ignore = 0
+    else:
+        # Some ticket got imported as closed but without a closed_at date, so
+        # let's ignore them all
+        to_ignore = (
+            session.query(model.Issue)
+            .filter(model.Issue.project_id == project.id)
+            .filter(model.Issue.closed_at == None)  # noqa
+            .filter(model.Issue.status == "Closed")
+            .count()
+        )
+
     # For each week from tomorrow, get the number of open tickets
-    tomorrow = datetime.datetime.utcnow() + datetime.timedelta(days=1)
+
     output = {}
     for week in range(53):
         end = tomorrow - datetime.timedelta(days=(week * 7))
@@ -5694,6 +5715,10 @@ def issues_history_stats(session, project, detailed=False):
             query_open = query_open.filter(model.Issue.status == "Open")
         open_ticket = query_open.count()
         cnt = open_ticket + closed_ticket - to_ignore
+        current_open = current_open - open_ticket + closed_ticket
+
+        if current_open < 0:
+            current_open = 0
         if cnt < 0:
             cnt = 0
         if detailed is False:
@@ -5702,7 +5727,7 @@ def issues_history_stats(session, project, detailed=False):
             output[start.isoformat()] = {
                 "open_ticket": open_ticket,
                 "closed_ticket": closed_ticket,
-                "count": cnt,
+                "count": current_open,
             }
 
     return output