# api/users.py
# 本文件定义学生相关的所有 API 路由（Controller 层）

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from typing import List,Optional

from sqlalchemy_fastapi_demo_1.database import get_db
from sqlalchemy_fastapi_demo_1.dao.students_dao import StudentDAO
from sqlalchemy_fastapi_demo_1.scheme.students import StudentCreate, StudentUpdate, StudentResponse

router = APIRouter(prefix="/students",tags=["学生管理接口"])

# 增加学生信息接口
@router.post("/",response_model=StudentResponse)
def create_student_api(
    student_in: StudentCreate,
    db: Session = Depends(get_db)
):
    student = StudentDAO.create_student(db=db, obj_in=student_in)
    return student


# 查询所有学生接口
@router.get("/all", response_model=List[StudentResponse])
async def get_all_api(
    skip: int = Query(0, ge=0, description="跳过的记录数"),
    limit: int = Query(100, ge=1, le=200, description="返回的最大记录数"),
    db: Session = Depends(get_db)   # 依赖注入获得数据库会话
):
    students = StudentDAO.get_students_all(db, skip=skip, limit=limit)
    return students   # FastAPI 自动根据 response_model 转换为 JSON

# 多条件查询接口
@router.get("/search",response_model=List[StudentResponse])
async def get_multi_condition_api(
    stu_id: Optional[int] =  Query(None, description="学生编号"),
    stu_name: Optional[str] = Query(None, description="学生姓名（支持模糊查询）"),
    class_id: Optional[int] = Query(None, description="班级编号"),
    skip: int = 0,
    limit: int = 100,
    db: Session = Depends(get_db)
):
    student = StudentDAO.query_multi_condition(
        db = db,
        stu_id = stu_id,
        stu_name = stu_name,
        class_id = class_id,
        skip = skip,
        limit = limit )
    return student

# 根据id查询单个学生接口
@router.get("/{stu_id}", response_model=StudentResponse)
async def get_student_by_id_api(
    stu_id: int,
    db: Session = Depends(get_db)
):
    student = StudentDAO.get_student_by_id(db=db, stu_id=stu_id)
    if not student:
        raise HTTPException(status_code=404, detail="用户不存在")
    return student

# 更改学生信息接口
@router.put("/{stu_id}",response_model=StudentResponse)
async def update_student_api(
        stu_id: int,
        stu_update: StudentUpdate,
        db: Session = Depends(get_db)
):
    """更新学生信息，支持部分字段更新"""
    # 检查学生是否存在
    existing = StudentDAO.get_student_by_id(db, stu_id)
    if not existing:
        raise HTTPException(status_code=404, detail="学生不存在")
    # 校验外键(班级和顾问是否存在)
    if stu_update.advisor_id is not None:
        advisor_exists = StudentDAO.inspect_advisor_id_unq(db, stu_update.advisor_id)
        if not advisor_exists:
            raise HTTPException(status_code=400, detail="该顾问不存在")
    if stu_update.class_id is not None:
        class_exists = StudentDAO.inspect_class_id_unq(db, stu_update.class_id)
        if not class_exists:
            raise HTTPException(status_code=400, detail="该班级不存在")
    # 直接调用 DAO 更新，学号不可改等逻辑已在 DAO 层处理
    student = StudentDAO.update_student(db = db , stu_id = stu_id , obj = stu_update)
    return student

# 逻辑删除接口：不返回完整学生实体，返回简单提示
@router.delete("/{stu_id}",status_code=204)
async def delete_student_api(
        stu_id: int,
        db: Session = Depends(get_db)
):
    StudentDAO.delete_student(db, stu_id)
    # 返回 None 表示 204 状态码（无内容）
    return None