chore: 将后端移动到 api/ 目录，准备合并为单仓库

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/submission/models.py

@@ -0,0 +1,215 @@
+import uuid
+from django.db import models
+from django.db.models import Avg
+from django_extensions.db.models import TimeStampedModel
+from django.core.exceptions import ValidationError
+from django.utils import timezone
+from django.db.models.signals import post_save
+from django.dispatch import receiver  # 导入receiver
+
+from account.models import RoleChoices, User
+from task.models import Task
+
+
+class FlagChoices(models.TextChoices):
+    RED = "red", "值得展示"
+    BLUE = "blue", "需要讲解"
+    GREEN = "green", "优秀作品"
+    YELLOW = "yellow", "需要改进"
+
+
+class ZoneChoices(models.TextChoices):
+    FEATURED = "featured", "精选"
+    LOW = "low", "待改进"
+    PENDING = "pending", "待评"
+
+
+class Submission(TimeStampedModel):
+    id = models.UUIDField(
+        primary_key=True,
+        default=uuid.uuid4,
+        editable=False,
+    )
+    user = models.ForeignKey(
+        User,
+        on_delete=models.CASCADE,
+        related_name="my_submissions",
+    )
+    task = models.ForeignKey(Task, on_delete=models.CASCADE)
+    score = models.FloatField(default=0.0, verbose_name="分数")
+    html = models.TextField(null=True, blank=True, verbose_name="HTML代码")
+    css = models.TextField(null=True, blank=True, verbose_name="CSS代码")
+    js = models.TextField(null=True, blank=True, verbose_name="JS代码")
+    flag = models.CharField(
+        max_length=10,
+        choices=FlagChoices.choices,
+        null=True,
+        blank=True,
+        default=None,
+        db_index=True,
+        verbose_name="标记",
+    )
+    raw_score = models.FloatField(default=0.0, verbose_name="原始加权分")
+    zone = models.CharField(
+        max_length=10,
+        choices=ZoneChoices.choices,
+        null=True,
+        blank=True,
+        default=None,
+        db_index=True,
+        verbose_name="分区",
+    )
+    view_count = models.PositiveIntegerField(default=0, verbose_name="查看次数")
+
+    class Meta:
+        ordering = ("-created",)
+
+    def __str__(self):
+        return f"{self.user.username} - {self.task.title}"
+
+    def get_task_type(self):
+        """
+        返回任务的具体类型（Challenge 或 Tutorial）
+        """
+        return self.task.task_type
+
+    def _update_zone(self, n: int):
+        if n < 5:
+            new_zone = ZoneChoices.PENDING
+        elif self.score >= 4.0:
+            new_zone = ZoneChoices.FEATURED
+        elif self.score < 3.0:
+            new_zone = ZoneChoices.LOW
+        else:
+            new_zone = None
+        if self.zone != new_zone:
+            self.zone = new_zone
+            self.save(update_fields=["zone"])
+
+    def update_score(self):
+        ratings = list(self.ratings.select_related("user").all())
+        n = len(ratings)
+
+        if n == 0:
+            self.raw_score = 0.0
+            self.score = 0.0
+            self.save(update_fields=["raw_score", "score"])
+            self._update_zone(n)
+            return
+
+        role_weights = [
+            0.5 if r.user.role == RoleChoices.SUPER
+            else 0.3 if r.user.role == RoleChoices.ADMIN
+            else 0.2
+            for r in ratings
+        ]
+        weighted_sum = sum(r.score * w for r, w in zip(ratings, role_weights))
+        weight_total = sum(role_weights)
+        self.raw_score = weighted_sum / weight_total
+
+        C = 3
+        global_mean = (
+            Submission.objects.filter(raw_score__gt=0)
+            .exclude(pk=self.pk)
+            .aggregate(Avg("raw_score"))["raw_score__avg"]
+        ) or self.raw_score
+
+        self.score = (C * global_mean + n * self.raw_score) / (C + n)
+        self.save(update_fields=["raw_score", "score"])
+        self._update_zone(n)
+
+    def save(self, *args, **kwargs):
+        super().save(*args, **kwargs)
+
+
+class Rating(models.Model):
+    user = models.ForeignKey(
+        User,
+        on_delete=models.CASCADE,
+        related_name="ratings",
+    )
+    submission = models.ForeignKey(
+        Submission,
+        on_delete=models.CASCADE,
+        related_name="ratings",
+    )
+    score = models.IntegerField(default=0, verbose_name="分数")
+    created = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        unique_together = ("user", "submission")
+
+    def __str__(self):
+        return f"{self.user.username} 评分了 {self.submission.id}，分数是 {self.score}"
+
+    def clean(self):
+        """
+        在保存之前检查用户当天的评分次数
+        """
+        today_start = timezone.now().replace(hour=0, minute=0, second=0, microsecond=0)
+        today_end = today_start + timezone.timedelta(days=1)
+        count = Rating.objects.filter(
+            user=self.user, created__range=(today_start, today_end)
+        ).count()
+
+        if self.user.role == RoleChoices.NORMAL and count >= 30:
+            raise ValidationError("普通用户每天最多只能评分30次。")
+
+    def save(self, *args, **kwargs):
+        self.clean()
+        super().save(*args, **kwargs)
+
+
+@receiver(post_save, sender=Rating)
+def update_submission_score_on_save(sender, instance, **kwargs):
+    """
+    当Rating保存时，更新对应的Submission的平均分
+    """
+    instance.submission.update_score()
+
+
+class ItemOrdering(models.TextChoices):
+    MANUAL = "manual", "手动排序"
+    AWARDED_AT = "awarded_at", "授奖时间倒序"
+    SCORE = "score", "评分倒序"
+    VIEW_COUNT = "view_count", "浏览量倒序"
+
+
+class Award(TimeStampedModel):
+    name = models.CharField(max_length=100, unique=True, verbose_name="奖项名称")
+    description = models.TextField(blank=True, default="", verbose_name="奖项简介")
+    sort_order = models.IntegerField(default=0, db_index=True, verbose_name="排序值")
+    is_active = models.BooleanField(default=True, verbose_name="是否启用")
+    item_ordering = models.CharField(
+        max_length=20,
+        choices=ItemOrdering.choices,
+        default=ItemOrdering.MANUAL,
+        verbose_name="作品排序方式",
+    )
+
+    class Meta:
+        ordering = ("sort_order",)
+
+    def __str__(self):
+        return self.name
+
+
+class SubmissionAward(TimeStampedModel):
+    submission = models.ForeignKey(
+        Submission, on_delete=models.CASCADE, related_name="awards"
+    )
+    award = models.ForeignKey(
+        Award, on_delete=models.CASCADE, related_name="submission_awards"
+    )
+    sort_order = models.IntegerField(default=0, db_index=True, verbose_name="手动排序值")
+    awarded_at = models.DateTimeField(
+        auto_now_add=True, db_index=True, verbose_name="授奖时间"
+    )
+    is_stale = models.BooleanField(default=False, verbose_name="有更新提交")
+
+    class Meta:
+        unique_together = ("submission", "award")
+        ordering = ("sort_order",)
+
+    def __str__(self):
+        return f"{self.award.name} - {self.submission}"