from fastapi import HTTPException
from sqlalchemy import func
from model.all_model import Student_Model,WlScore,Employment_info

# 实现根据年龄查询学生信息的功能
def select_age(min_age,max_age,db):
    try:
        if min_age is None and max_age is None:
            raise HTTPException(status_code=400, detail="请至少传入一个参数")
        db = db.query(Student_Model)
        if min_age is not None:
            db = db.filter(Student_Model.age >= min_age,Student_Model.delete_status == 0)
        if max_age is not None:
            db = db.filter(Student_Model.age <= max_age,Student_Model.delete_status == 0)
        return db.all()
    except HTTPException:
        raise
    except Exception:
        raise HTTPException(status_code=500,detail="查询异常")

# 实现统计每个班级的学员总数以及男女生的总数的功能
def select_all(db):
    try:
        l1 = db.query(Student_Model.class_id,Student_Model.gender,func.count(1).label('cnt'))\
            .group_by(Student_Model.class_id,Student_Model.gender).all()
        all_cnt = sum(i.cnt for i in l1)

        l2 = []
        for i in l1:
            l2.append({
                "all_cnt": all_cnt,
                "class_id": i.class_id,
                "gender": i.gender,
                "cnt": i.cnt
            })
        return l2
    except Exception:
        raise HTTPException(status_code=500,detail="查询异常")

# 实现根据成绩查询学员信息的功能
def select_score(min_score,max_score,db):
    try:
        if min_score is None and max_score is None:
            raise HTTPException(status_code=400, detail="请至少传入一个参数")
        db = db.query(WlScore.score
                      ,Student_Model.stu_name
                      ,Student_Model.age
                      ,Student_Model.gender
                      ,Student_Model.native_place
                      ,Student_Model.school
                      ,Student_Model.major
                      ,Student_Model.degree
                      ,Student_Model.admission_date
                      ,Student_Model.graduation_date
                      ,Student_Model.progress
                      )\
                .join(WlScore,WlScore.stu_id == Student_Model.stu_id)\
                .filter(WlScore.delete_status==0,Student_Model.delete_status == 0)
        if min_score is not None:
            db = db.filter(WlScore.score >= min_score)
        if max_score is not None:
            db = db.filter(WlScore.score <= max_score)
        return db.all()
    except HTTPException:
        raise
    except Exception:
        raise HTTPException(status_code=500,detail="查询异常")

# 实现统计每次考试每个班级的平均分并排序的功能
def select_avg_score(db):
    try:
        l1 = db.query(Student_Model.class_id,func.avg(WlScore.score).label('avg_score'))\
            .join(Student_Model,WlScore.stu_id == Student_Model.stu_id)\
            .filter(WlScore.delete_status==0,Student_Model.delete_status == 0)\
            .group_by(Student_Model.class_id)\
            .order_by(func.avg(WlScore.score)).all()
        return l1
    except Exception:
        raise HTTPException(status_code=500,detail="查询异常")

# 实现统计薪资最高的前五名的学员信息
def select_salary(db):
    try:
        l1 = db.query(Employment_info.salary
                      ,Student_Model.stu_name
                      ,Student_Model.age
                      ,Student_Model.gender
                      ,Student_Model.native_place
                      ,Student_Model.school
                      ,Student_Model.major
                      ,Student_Model.degree
                      ,Student_Model.admission_date
                      ,Student_Model.graduation_date
                      ,Student_Model.progress)\
            .join(Employment_info,Employment_info.stu_id==Student_Model.stu_id)\
            .filter(Employment_info.delete_status==0,Student_Model.delete_status == 0)\
            .order_by(Employment_info.salary.desc())\
            .limit(5).all()
        return l1
    except Exception:
        raise HTTPException(status_code=500,detail="查询异常")

# 实现统计每个班级的平均就业时长
def select_avg_days(db):
    try:
        l1 = db.query(Student_Model.class_id,
            func.coalesce(
                func.avg(
                    func.datediff(
                        Employment_info.offer_issuance_date, Employment_info.employment_opening_date
                    )
                ),0).label("avg_days")
            ).join(Employment_info,Employment_info.stu_id == Student_Model.stu_id)\
            .filter(Student_Model.delete_status == 0,
                    Employment_info.delete_status == 0,
                    Employment_info.employment_opening_date.isnot(None),
                    Employment_info.offer_issuance_date.isnot(None),)\
            .group_by(Student_Model.class_id)\
            .order_by(func.avg(func.datediff(Employment_info.offer_issuance_date,Student_Model.admission_date)).desc()).all()
        return l1
    except Exception:
        raise HTTPException(status_code=500, detail="查询异常")

#统计每个学⽣的就业时⻓
def select_days(db):
    try:
        l2 =db.query(Employment_info.stu_id
                    ,func.coalesce(func.datediff(Employment_info.offer_issuance_date
                                   ,Employment_info.employment_opening_date),0)\
                     .label("diff_days")
                     ).filter(Employment_info.delete_status == 0).all()
        return l2
    except Exception:
        raise HTTPException(status_code=500, detail="查询异常")


# 薪资区间分布：统计薪资在5k以下、5k-10k、10k-15k、15k以上的人数分布，反映学生的整体就业质量。
def classify_salary(db):
    try:
        a=b=c=d=0
        l=db.query(Employment_info).filter(Employment_info.delete_status==0).all()
        for i in l:
            if i.salary is None:
                continue
            elif i.salary<5000:
                a+=1
            elif 5000<=i.salary<10000:
                b+=1
            elif 10000<=i.salary<15000:
                c+=1
            else:
                d+=1
        return {'5k以下': a, '5k-10k': b, '10k-15k': c, '15k': d}
    except:
        raise HTTPException(status_code=500,detail='查询异常！')