Display score change in submissions admin

oioioi/acm/controllers.py

@@ -201,6 +201,9 @@ def can_see_round(self, request_or_context, round, no_admin=False):
     def get_default_safe_exec_mode(self):
         return 'cpu'
 
+    def display_score_change(self):
+        return False
+
 
 class ACMOpenContestController(ACMContestController):
     description = _("ACM style contest (open)")

oioioi/contests/admin.py

@@ -712,6 +712,8 @@ def get_list_display(self, request):
         ]
         if request.contest:
             list_display.remove('contest_display')
+            if request.contest.controller.display_score_change():
+                list_display.append('score_diff_display')
         return list_display
 
     def get_list_display_links(self, request, list_display):
@@ -848,6 +850,22 @@ def score_display(self, instance):
     score_display.short_description = _("Score")
     score_display.admin_order_field = 'score_with_nulls_smallest'
 
+    def score_diff_display(self, instance):
+        contest_controller = instance.problem_instance.contest.controller
+        if not contest_controller.display_score_change() or instance.kind != 'NORMAL':
+            return format_html('<span class="text-secondary">-</span>')
+
+        previous_submission = Submission.objects.filter(
+            user=instance.user,
+            problem_instance=instance.problem_instance,
+            kind='NORMAL',
+            date__lt=instance.date,
+        ).order_by('-date').first()
+        return contest_controller.render_score_change(previous_submission, instance)
+
+    score_diff_display.short_description = _("Score change")
+    score_diff_display.admin_order_field = 'score'
+
     def contest_display(self, instance):
         return instance.problem_instance.contest
 

oioioi/contests/controllers.py

@@ -9,6 +9,7 @@
 from django.db.models import Subquery
 from django.template.loader import render_to_string
 from django.urls import reverse
+from django.utils.html import format_html
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import gettext_noop
@@ -974,6 +975,36 @@ def _is_partial_score(self, test_report):
     def show_default_fields(self, problem_instance):
         return problem_instance.problem.controller.show_default_fields(problem_instance)
 
+    def display_score_change(self):
+        """
+        Whether to display score change for a submission in submissions admin.
+        """
+        return True
+
+    def _calculate_score_change(self, before, after):
+        """
+        Calculate score difference between two scores.
+        """
+        if before is None or after is None:
+            return after
+        cls = type(before)
+        return cls(after.value - before.value)
+
+    def render_score_change(self, previous_submission, current_submission):
+        """
+        Calculates and renders score change between two submissions.
+        """
+        prev_score = previous_submission.score if previous_submission else None
+        curr_score = current_submission.score if current_submission else None
+        diff = self._calculate_score_change(prev_score, curr_score)
+        if diff is None:
+            return format_html('<span class="text-secondary">-</span>')
+        if diff.value == 0:
+            return format_html('<span class="text-secondary">0</span>')
+        if diff.value > 0:
+            return format_html('<span class="text-success">+{}</span>', diff.value)
+        return format_html('<span class="text-danger">{}</span>', diff.value)
+
 
 class PastRoundsHiddenContestControllerMixin(object):
     """ContestController mixin that hides past rounds