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/task/models.py

@@ -0,0 +1,124 @@
+from django.db import models
+from django.conf import settings
+from django_extensions.db.models import TimeStampedModel
+
+
+class TaskTypeChoices(models.TextChoices):
+    CHALLENGE = "challenge", "挑战"
+    TUTORIAL = "tutorial", "教程"
+    CREATION = "creation", "创作"
+
+
+class Task(TimeStampedModel):
+    display = models.IntegerField(db_index=True, verbose_name="序号")
+    title = models.CharField(max_length=100, verbose_name="标题")
+    content = models.TextField(verbose_name="内容")
+    task_type = models.CharField(
+        max_length=20,
+        choices=TaskTypeChoices.choices,
+        editable=False,
+        verbose_name="类型",
+    )
+    is_public = models.BooleanField(default=False, verbose_name="是否公开")
+    example_html = models.TextField(null=True, blank=True, verbose_name="示例HTML")
+    example_css = models.TextField(null=True, blank=True, verbose_name="示例CSS")
+    example_js = models.TextField(null=True, blank=True, verbose_name="示例JS")
+
+    class Meta:
+        unique_together = ("display", "task_type")
+
+    def save(self, *args, **kwargs):
+        if not self.task_type:
+            self.task_type = self.__class__.__name__.lower()
+        super().save(*args, **kwargs)
+
+
+class Tutorial(Task):
+    def __str__(self):
+        return self.title
+
+    class Meta:
+        ordering = ("display",)
+        verbose_name = "教程"
+        verbose_name_plural = verbose_name
+
+
+class Challenge(Task):
+    score = models.IntegerField(default=0)
+    pass_score = models.FloatField(null=True, blank=True, verbose_name="通过分数线")
+    author = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name="authored_challenges",
+        verbose_name="出题人",
+    )
+
+    @property
+    def author_name(self):
+        return self.author.username if self.author_id else ""
+
+    def __str__(self):
+        return self.title
+
+    class Meta:
+        ordering = ("display",)
+        verbose_name = "挑战"
+        verbose_name_plural = verbose_name
+
+
+class Creation(Task):
+    """
+    用户自己创建的主题：标题和内容都由用户自己写，只有创作者本人能看到和修改
+    """
+
+    owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="creations",
+        verbose_name="创作者",
+    )
+    html = models.TextField(blank=True, default="", verbose_name="HTML代码")
+    css = models.TextField(blank=True, default="", verbose_name="CSS代码")
+    js = models.TextField(blank=True, default="", verbose_name="JS代码")
+
+    @property
+    def owner_name(self):
+        return self.owner.username if self.owner_id else ""
+
+    def save(self, *args, **kwargs):
+        if not self.display:
+            last = (
+                Creation.objects.order_by("-display")
+                .values_list("display", flat=True)
+                .first()
+            )
+            self.display = (last or 0) + 1
+        super().save(*args, **kwargs)
+
+    def __str__(self):
+        return self.title
+
+    class Meta:
+        ordering = ("-created",)
+        verbose_name = "创作"
+        verbose_name_plural = verbose_name
+
+
+def task_asset_upload_to(instance, filename):
+    return f"tasks/{instance.task.task_type}/{instance.task.display}/{instance.name}"
+
+
+class TaskAsset(models.Model):
+    task = models.ForeignKey(Task, on_delete=models.CASCADE, related_name="assets")
+    name = models.CharField(max_length=100, verbose_name="文件名")
+    file = models.FileField(upload_to=task_asset_upload_to, verbose_name="文件")
+
+    class Meta:
+        unique_together = ("task", "name")
+        verbose_name = "任务素材"
+        verbose_name_plural = verbose_name
+
+    def __str__(self):
+        return f"{self.task} / {self.name}"