Add basic quiz functionality

tvdt/quiz/models/candidate.py

@@ -0,0 +1,48 @@
+from typing import Self
+
+from django.db import models
+from django.utils.translation import gettext_lazy as _
+from django_stubs_ext.db.models import TypedModelMeta
+
+from .given_answer import GivenAnswer
+from .question import NoActiveTestForSeason, QuizAlreadyFinished, Question
+
+
+class Candidate(models.Model):
+    season = models.ForeignKey(
+        "Season",
+        on_delete=models.CASCADE,
+        related_name="candidates",
+        verbose_name="season",
+    )
+    name = models.CharField(max_length=16, verbose_name=_("name"))
+
+    def get_next_question(self, candidate: Self) -> "Question":
+        quiz = candidate.season.active_quiz
+        if quiz is None:
+            raise NoActiveTestForSeason()
+
+        question = (
+            Question.objects.filter(quiz=quiz)
+            .exclude(
+                id__in=GivenAnswer.objects.filter(
+                    candidate=candidate, question__quiz=quiz
+                ).values_list("question_id", flat=True)
+            )
+            .first()
+        )
+
+        if question is None:
+            raise QuizAlreadyFinished()
+
+        return question
+
+    def __str__(self) -> str:
+        return f"{self.name} ({self.season})"
+
+    class Meta(TypedModelMeta):
+        unique_together = ["season", "name"]
+        indexes = [models.Index(fields=["season", "name"])]
+
+        verbose_name = _("candidate")
+        verbose_name_plural = _("candidates")