from sqlalchemy import func, desc
from sqlalchemy.exc import SQLAlchemyError
from model.epy_model import Employment
from fastapi import HTTPException
from model.stu_model import Student
from model.sc_model import Scores

# ① 超30岁学员
def get_stu_over_30(db):
    try:
        rows = db.query(Student).filter(Student.age>30,Student.is_deleted == 0).all()
        return [{'id': i.stu_id, 'name': i.stu_name} for i in rows]
    except SQLAlchemyError as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询超三十岁学员信息失败:{str(e)}')

# ② 各班人数 + 男女比
def get_class_gender_count(db):
    try:
        rows = db.query(
            Student.class_id,
            Student.gender,
            func.count(1).label('num')
        ).group_by(Student.class_id, Student.gender).all()
        return [{'班级': r.class_id, '性别': r.gender, '人数':r.num } for r in rows]
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询各班人数与男女比例失败:{str(e)}')

# ③ 每次考试都≥80分的学生
def get_stu_all_pass_80(db):
    try:
        rows = db.query(
            Scores.stu_id,
            Student.stu_name,
            func.min(Scores.score).label('min_score')
        ).join(Student, Student.stu_id == Scores.stu_id) \
         .group_by(Scores.stu_id, Student.stu_name) \
         .having(func.min(Scores.score) >= 80).all()
        t = ['stu_id', 'stu_name', 'min_score']
        l = [dict(zip(t, row)) for row in rows]
        return  l
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询成绩大于80的学生失败:{str(e)}')

# ④ 两次以上不及格的学生
def get_stu_two_fail(db):
    try:
        rows = db.query(
            Student.stu_name,
            Student.class_id,
        ).join(Scores, Scores.stu_id == Student.stu_id) \
         .filter(Scores.score < 60) \
         .group_by(Scores.stu_id,Student.stu_name,Student.class_id) \
         .having(func.count(Scores.id) >= 2).all()
        t = ['stu_name', 'class_id']
        l = [dict(zip(t, row)) for row in rows]
        return l
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询两次不及格的学生失败:{str(e)}')

# ⑤ 每次考试各班平均分（降序）
def get_class_avg_sc(db):
    try:
        rows = db.query(
            Scores.exam_seq,
            Student.class_id,
            func.avg(Scores.score).label('avg_score')
        ).join(Student, Student.stu_id == Scores.stu_id) \
         .group_by(Scores.exam_seq, Student.class_id) \
         .order_by(desc('avg_score')).all()
        t = ['exam_seq', 'class_id','avg_score']
        l = [dict(zip(t, row)) for row in rows]
        return l
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400, detail=f'查询各班平均分失败:{str(e)}')

# ⑥ 薪资前五名
def get_top5_salary(db):
    try:
        rows = db.query(Student.stu_name, Student.class_id,Employment.work_date,Employment.company,Employment.salary).join(Student, Student.stu_id == Employment.stu_id).order_by(Employment.salary.desc()).limit(5).all()
        t = ['stu_name','class_id','work_date','company','salary']
        l = [dict(zip(t, row)) for row in rows]
        print(l)
        return {'code': 200, 'data': l}
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询薪资前五名失败失败:{str(e)}')

# ⑦ 每个学生就业时长
def get_stu_duration(db):
    try:
        rows = db.query(Employment.stu_id,func.datediff(Employment.offer_date,Employment.open_date).label('offer_diff')).group_by(Employment.stu_id,Employment.offer_date,Employment.open_date).all()
        t = ['s_id', 'offer_diff']
        l = [dict(zip(t, row)) for row in rows]
        return {'code': 200, 'data': l}
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询每个学生的就业时长失败:{str(e)}')

# ⑧ 各班平均就业时长
def get_class_avg_duration(db):
    try:
        rows = db.query(
            Student.class_id,
          func.avg(func.datediff(Employment.offer_date, Employment.open_date)).label('avg_duration')
        ).join(Student, Student.stu_id == Employment.stu_id).filter(
            Employment.open_date.isnot(None)
        ).group_by(Student.class_id).all()
        t = ['class_id', 'avg_duration']
        l = [dict(zip(t, row)) for row in rows]
        return l
    except Exception as e:
        db.rollback()
        raise HTTPException(status_code=400,detail=f'查询各班平均就业时长失败:{str(e)}')