# api/scores.py
# 成绩模块接口：录入（含 60 分红线预警）、修改、删除、查询
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session

from core.deps import get_current_user, require_roles, get_teacher_class_ids
from dao.scores_dao import ScoreDAO
from dao.students_dao import StudentDAO
from database import get_db
from model.user import User
from scheme.scores import (
    ScoreAdd,
    ScoreUpdate,
    ScoreDelete,
    ScoreResponse,
    ScoreListResponse,
    ScoreAddResponse,
)

router = APIRouter()


def _can_manage_student_scores(db: Session, user: User, student) -> bool:
    """教师只能管理自己所带班级学生的成绩；管理员不受限"""
    if user.role == "admin":
        return True
    if user.role == "teacher":
        return student.class_id in get_teacher_class_ids(db, user.teacher_id)
    return False


# ---------- 录入成绩 ----------
@router.post("/add", response_model=ScoreAddResponse, summary="录入成绩（低于60分触发预警）")
async def add_score(
    score_data: ScoreAdd,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_roles("admin", "teacher")),
):
    # 外键校验：学生必须存在
    student = StudentDAO.get_active(db, score_data.stu_id)
    if student is None:
        raise HTTPException(status_code=404, detail="学生不存在，或已被软删除")
    if not _can_manage_student_scores(db, current_user, student):
        raise HTTPException(status_code=403, detail="教师只能管理自己所带班级学生的成绩")
    # 复合主键冲突校验
    existing = ScoreDAO.get_one(db, score_data.stu_id, score_data.exam_id, include_deleted=True)
    if existing:
        raise HTTPException(status_code=409, detail="该学生此考核序次的成绩已存在，请使用修改接口")
    db_score = ScoreDAO.add_score(db, score_data)
    item = ScoreDAO.build_score_item(db_score, stu_name=student.stu_name)
    warning = None
    if item["is_warning"]:
        warning = f"预警：学生 {student.stu_name}（学号 {student.stu_id}）第 {score_data.exam_id} 次考核成绩 {score_data.score} 分低于 {ScoreDAO.WARNING_LINE} 分红线，需要多加关注！"
    return ScoreAddResponse(score=ScoreResponse(**item), warning=warning)


# ---------- 查询学生成绩 ----------
@router.get("/query", response_model=ScoreListResponse, summary="查询成绩（按学号或考核序次）")
async def get_scores(
    stu_id: int = Query(None, ge=1, description="按学号查询（学生角色只能查自己）"),
    exam_id: int = Query(None, ge=1, description="按考核序次查询"),
    skip: int = Query(0, ge=0),
    limit: int = Query(100, ge=1, le=200),
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    # 学生角色只能查自己的成绩
    if current_user.role == "student":
        stu_id = current_user.stu_id
    if stu_id is None and exam_id is None:
        raise HTTPException(status_code=400, detail="stu_id 与 exam_id 至少提供一个")
    if stu_id is not None:
        rows = ScoreDAO.get_by_student(db, stu_id)
        student = StudentDAO.get_active(db, stu_id)
        stu_name = student.stu_name if student else None
        items = [ScoreResponse(**ScoreDAO.build_score_item(s, stu_name)) for s in rows]
        return ScoreListResponse(total=len(items), items=items)
    total, rows = ScoreDAO.get_by_exam(db, exam_id, skip=skip, limit=limit)
    items = []
    for s in rows:
        student = StudentDAO.get_active(db, s.stu_id)
        items.append(
            ScoreResponse(**ScoreDAO.build_score_item(s, student.stu_name if student else None))
        )
    return ScoreListResponse(total=total, items=items)


# ---------- 修改成绩 ----------
@router.put("/update", response_model=ScoreResponse, summary="修改指定学生的某次成绩")
async def update_score(
    score_data: ScoreUpdate,
    stu_id: int = Query(..., ge=1, description="学生编号"),
    exam_id: int = Query(..., ge=1, description="考核序次"),
    db: Session = Depends(get_db),
    current_user: User = Depends(require_roles("admin", "teacher")),
):
    student = StudentDAO.get_active(db, stu_id)
    if student is None:
        raise HTTPException(status_code=404, detail="学生不存在，或已被软删除")
    if not _can_manage_student_scores(db, current_user, student):
        raise HTTPException(status_code=403, detail="教师只能管理自己所带班级学生的成绩")
    db_score = ScoreDAO.update_score(db, stu_id, exam_id, score_data.score)
    if db_score is None:
        raise HTTPException(status_code=404, detail="该学生此考核序次的成绩不存在")
    return ScoreResponse(**ScoreDAO.build_score_item(db_score, student.stu_name))


# ---------- 删除成绩 ----------
@router.post("/delete", status_code=204, summary="删除指定学生的某次成绩（逻辑删除）")
async def delete_score(
    body: ScoreDelete,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_roles("admin", "teacher")),
):
    student = StudentDAO.get_active(db, body.stu_id)
    if student is None:
        raise HTTPException(status_code=404, detail="学生不存在，或已被软删除")
    if not _can_manage_student_scores(db, current_user, student):
        raise HTTPException(status_code=403, detail="教师只能管理自己所带班级学生的成绩")
    success = ScoreDAO.delete_score(db, body.stu_id, body.exam_id)
    if not success:
        raise HTTPException(status_code=404, detail="该成绩不存在，或已被删除")
    return None