Upload to the good place

apps/participation/models.py

@@ -312,6 +312,15 @@ class Pool(models.Model):
         verbose_name_plural = _("pools")
 
 
+def get_solution_filename(instance, filename):
+    return f"solutions/{instance.participation.team.trigram}_{instance.problem}" \
+           + ("final" if instance.final_solution else "")
+
+
+def get_random_synthesis_filename(instance, filename):
+    return "syntheses/" + get_random_string(64)
+
+
 class Solution(models.Model):
     participation = models.ForeignKey(
         Participation,
@@ -331,14 +340,15 @@ class Solution(models.Model):
 
     file = models.FileField(
         verbose_name=_("file"),
-        upload_to="solutions/",
+        upload_to=get_solution_filename,
         unique=True,
         blank=True,
         default="",
     )
 
     def __str__(self):
-        return repr(self)
+        return _("Solution of team {team} for problem {problem}")\
+            .format(team=self.participation.team.name, problem=self.problem)
 
     class Meta:
         verbose_name = _("solution")
@@ -369,7 +379,7 @@ class Synthesis(models.Model):
 
     file = models.FileField(
         verbose_name=_("file"),
-        upload_to="syntheses/",
+        upload_to=get_random_synthesis_filename,
         unique=True,
         blank=True,
         default="",