from sqlalchemy import Column, Integer, String, Boolean, Date, Table, ForeignKey
from sqlalchemy.orm import relationship
from database import Base



teacher_classes = Table(
    'teacher_classes',
    Base.metadata,
    Column('teacher_id', ForeignKey('teacher.t_id'), primary_key=True),
    Column('class_id', ForeignKey('classes.class_id'), primary_key=True)
)

class Classes(Base):
    __tablename__ = 'classes'
    class_id = Column(Integer, primary_key=True,autoincrement=True)
    head_teacher_id = Column(Integer, ForeignKey('teacher.t_id'), nullable=False)
    create_time = Column(Date,nullable=False)
    class_name = Column(String(50), nullable=False, unique=True)
    class_delete = Column(Boolean, default=False)
    counselor_id = Column(Integer, ForeignKey('counselor.id'))

    students = relationship('Student', back_populates='classes')
    teachers = relationship("Teacher", secondary=teacher_classes, back_populates="classes")
    counselor = relationship("Counselor", back_populates="classes")