from sqlalchemy import Column, Integer, String, DateTime, Boolean, Text, DECIMAL, ForeignKey, Index, UniqueConstraint
from sqlalchemy.orm import relationship
from datetime import datetime
from database import Base


class BaseModel:
    id = Column(Integer, primary_key=True, autoincrement=True)
    create_time = Column(DateTime, default=datetime.utcnow, nullable=False)
    update_time = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False)
    is_deleted = Column(Boolean, default=False, nullable=False)
    delete_time = Column(DateTime, nullable=True)


class Teacher(Base, BaseModel):
    __tablename__ = "teachers"

    num = Column(String(30), unique=True, nullable=False, index=True, comment="老师编号")
    name = Column(String(30), nullable=False, default='')
    age = Column(Integer, default=18)
    sex = Column(Integer, default=0, comment="0未知 1男 2女")
    home_place = Column(String(50), comment="家乡")
    college = Column(String(50), comment="毕业院校")
    specialty = Column(String(50), comment="专业")
    enrollment_time = Column(DateTime, comment="入学时间")
    graduate_time = Column(DateTime, comment="毕业时间")
    education = Column(String(50), comment="学历")
    work_experience = Column(Text, comment="工作经验")
    coach_area = Column(String(50), comment="教学方向：应用，项目，算法")

    head_teacher_of = relationship("Class", foreign_keys="Class.head_teacher_id", back_populates="head_teacher")
    coach_teacher_of = relationship("Class", foreign_keys="Class.coach_teacher_id", back_populates="coach_teacher")
    tutor_teacher_of = relationship("Class", foreign_keys="Class.tutor_teacher_id", back_populates="tutor_teacher")
    advisor_of = relationship("Student", foreign_keys="Student.advisor_id", back_populates="advisor")


class Class(Base, BaseModel):
    __tablename__ = "classes"

    num = Column(String(30), unique=True, nullable=False, index=True, comment="班级编号")
    name = Column(String(30), nullable=False, comment="班级名称")
    class_start_time = Column(DateTime, comment="开课时间")

    head_teacher_id = Column(Integer, ForeignKey("teachers.id"), comment="班主任")
    coach_teacher_id = Column(Integer, ForeignKey("teachers.id"), comment="授课老师")
    tutor_teacher_id = Column(Integer, ForeignKey("teachers.id"), comment="助教老师")

    head_teacher = relationship("Teacher", foreign_keys=[head_teacher_id], back_populates="head_teacher_of")
    coach_teacher = relationship("Teacher", foreign_keys=[coach_teacher_id], back_populates="coach_teacher_of")
    tutor_teacher = relationship("Teacher", foreign_keys=[tutor_teacher_id], back_populates="tutor_teacher_of")
    students = relationship("Student", back_populates="klass")
    employments = relationship("Employment", back_populates="klass")


class Student(Base, BaseModel):
    __tablename__ = "students"

    num = Column(String(30), unique=True, nullable=False, index=True, comment="学生编号")
    name = Column(String(30), nullable=False, default='')
    age = Column(Integer, default=18)
    sex = Column(Integer, default=0, comment="0未知 1男 2女")
    home_place = Column(String(50), comment="家乡")
    college = Column(String(50), comment="毕业院校")
    specialty = Column(String(50), comment="专业")
    enrollment_time = Column(DateTime, comment="入学时间")
    graduate_time = Column(DateTime, comment="毕业时间")
    education = Column(String(50), comment="学历")

    class_id = Column(Integer, ForeignKey("classes.id"), nullable=False, default=0, index=True)
    advisor_id = Column(Integer, ForeignKey("teachers.id"), comment="顾问id")

    klass = relationship("Class", back_populates="students")
    advisor = relationship("Teacher", foreign_keys=[advisor_id], back_populates="advisor_of")
    scores = relationship("Score", back_populates="student")
    employment = relationship("Employment", back_populates="student", uselist=False)


class Score(Base, BaseModel):
    __tablename__ = "scores"

    sid = Column(Integer, ForeignKey("students.id"), nullable=False, index=True, comment="学生ID")
    num = Column(String(30), nullable=False, comment="考核序次")
    score = Column(DECIMAL(10, 2), nullable=False, comment="分数")

    student = relationship("Student", back_populates="scores")

    __table_args__ = (
        UniqueConstraint('sid', 'num', name='uk_sid_score'),
        Index('idx_sid', 'sid'),
    )


class Employment(Base, BaseModel):
    __tablename__ = "employment"

    sid = Column(Integer, ForeignKey("students.id"), unique=True, comment="学生ID")
    class_id = Column(Integer, ForeignKey("classes.id"), nullable=False, index=True, comment="班级ID")
    employment_open_time = Column(DateTime, comment="就业开放时间")
    offer_recived_time = Column(DateTime, comment="offer下发时间")
    employment_company = Column(String(50), comment="就业公司")
    employment_salary = Column(DECIMAL(20, 5), comment="就业薪资")

    student = relationship("Student", back_populates="employment")
    klass = relationship("Class", back_populates="employments")

    __table_args__ = (
        UniqueConstraint('sid', name='uk_sid'),
        Index('idx_class_id', 'class_id'),
    )