from datetime import datetime
from flask_login import UserMixin
from . import db, login_manager


class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, nullable=False)
    password_hash = db.Column(db.String(255), nullable=False)


class Student(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False)
    student_no = db.Column(db.String(32), unique=True, nullable=False)
    name = db.Column(db.String(64), nullable=False)
    major = db.Column(db.String(128))
    total_score = db.Column(db.Float, default=0.0)
    attendance_count = db.Column(db.Integer, default=0)
    random_called_count = db.Column(db.Integer, default=0)


class RollCall(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False)
    student_id = db.Column(db.Integer, db.ForeignKey("student.id"), nullable=False)
    call_time = db.Column(db.DateTime, default=datetime.utcnow)
    mode = db.Column(db.String(16), nullable=False)  # random / sequence
    status = db.Column(
        db.String(16), nullable=False
    )  # absent / distracted / attended
    score_change = db.Column(db.Float, nullable=False, default=0.0)

    student = db.relationship("Student", backref="roll_calls")

    # user 关系可按需在查询中使用，不强制 backref


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))