Add report cooldowns

This is to prevent report flooding/spamming.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/forms.py

@@ -101,8 +101,27 @@ class ReportForm(ModelForm):
                 record = ReportRecord.objects.get(post=self.op)
             except ReportRecord.DoesNotExist:
                 record = ReportRecord.objects.create(post=self.op)
-        if record.report_set.filter(ip=self.instance.ip):
+
+        ip = self.instance.ip
+        if record.report_set.filter(ip=ip):
             raise ValidationError(_("You have already reported this post."))
+
+        # Not sure if it's possible to use the ORM to get a related field of a
+        # related field - report.record.post.board
+        board = self.op.board
+        all_reports = [
+            r
+            for r in Report.objects.filter(ip=ip).order_by("-created")
+            if r.record.post.board == board
+        ]
+        if all_reports:
+            last_report = all_reports[0]
+            now = timezone.now()
+            delta = now - last_report.created
+            if delta < board.report_cooldown:
+                raise ValidationError(
+                    _(f"Please wait a few seconds before submitting another report"),
+                )
         self.instance.record = record
         return super(ReportForm, self).clean()