fix: validate import identities and selected materials consistently

backend/wisegrade/api.py

@@ -3,7 +3,7 @@ from pathlib import Path
 
 from fastapi import APIRouter, Depends, HTTPException
 from fastapi.responses import FileResponse
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, field_validator, model_validator
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
@@ -67,16 +67,33 @@ class FileConfirm(BaseModel):
 
 class ProjectConfirm(BaseModel):
     relative_dir: str
-    student_no: str = Field(pattern=r"^\d{5,20}$")
+    student_no: str = Field(pattern=r"^[0-9]{5,20}$")
     name: str = Field(min_length=1)
     topic: str = Field(min_length=1)
     direction: str = ""
-    files: list[FileConfirm]
+    files: list[FileConfirm] = Field(min_length=1)
+
+    @field_validator("student_no", "name", "topic", "direction", mode="before")
+    @classmethod
+    def trim_identity(cls, value):
+        return value.strip() if isinstance(value, str) else value
+
+    @model_validator(mode="after")
+    def validate_selection(self):
+        selected = [file for file in self.files if file.status != "ignored"]
+        if not selected:
+            raise ValueError("至少选择1份资料")
+        categories = [file.category for file in selected]
+        if any(category not in CATEGORIES for category in categories):
+            raise ValueError("请选择有效材料类型")
+        if len(set(categories)) != len(categories):
+            raise ValueError("每类材料只允许选择1份，其余请设为忽略")
+        return self
 
 
 class ImportConfirm(BaseModel):
     course_version_id: int
-    projects: list[ProjectConfirm]
+    projects: list[ProjectConfirm] = Field(min_length=1)
 
 
 class BatchInput(BaseModel):