Na stránce kola si stěžujeme, pokud soubor se zadáním neexistuje

Closes #208.

mo/web/org_round.py

@@ -231,6 +231,7 @@ def org_round(id: int):
         can_upload=rr.offer_upload_feedback(),
         can_view_statement=rr.can_view_statement(),
         can_add_contest=g.gatekeeper.rights_generic().have_right(Right.add_contest),
+        statement_exists=mo.web.util.task_statement_exists(round),
     )
 
 

mo/web/templates/org_round.html

@@ -45,7 +45,9 @@
 	<tr><td>Dozor odevzdává do<td>{{ round.pr_submit_end|time_and_timedelta }}
 	<tr><td>Zadání<td>
 {% if round.tasks_file %}
-	{% if can_view_statement %}
+	{% if not statement_exists %}
+		<span class=error>soubor neexistuje</span>
+	{% elif can_view_statement %}
 		<a href='{{ url_for('org_task_statement', id=round.round_id) }}'>stáhnout</a>
 	{% else %}
 		není dostupné

mo/web/util.py

@@ -42,6 +42,13 @@ class PagerForm(FlaskForm):
         return (count, query)
 
 
+def task_statement_exists(round: db.Round) -> bool:
+    if round.tasks_file is None:
+        return False
+    file = os.path.join(mo.util.data_dir('statements'), round.tasks_file)
+    return os.path.isfile(file)
+
+
 def send_task_statement(round: db.Round) -> Response:
     assert round.tasks_file is not None
     file = os.path.join(mo.util.data_dir('statements'), round.tasks_file)