from datetime import date, datetime
from typing import Optional, Union


class Student:
    """学生实体类，包含学生的基本信息和相关属性"""

    def __init__(self,
                 name: str,  # 姓名，非空字符串
                 id_card: str,  # 身份证号, 唯一标识学生，非空字符串
                 stu_id: str,  # 学号, 唯一标识学生，非空字符串
                 gender: Optional[bool] = None,  # 性别，True为男，False为女
                 height: Optional[int] = None,  # 身高, 单位为cm
                 weight: Optional[float] = None,  # 体重, 单位为kg,小数点后一位
                 enrollment_date: Optional[Union[date, str]] = None,  # 入学日期
                 class_name: Optional[str] = None,  # 班级名称
                 major: Optional[str] = None,  # 专业名称
                 email: Optional[str] = None,  # 电子邮箱
                 phone: Optional[str] = None  # 联系电话
                 ):
        # 基本信息
        self.name = name
        self.id_card = id_card
        self.stu_id = stu_id
        self.gender = gender
        self.height = height
        self.weight = weight
        self.enrollment_date = enrollment_date
        self.class_name = class_name
        self.major = major
        self.email = email
        self.phone = phone

        # 从身份证号码派生的属性
        self._age = None
        self._birthday = None
        self._parse_id_card()

    def _parse_id_card(self):
        """从身份证号码中提取出生日期和计算年龄"""
        if not self.id_card or len(self.id_card) != 18:
            return

        try:
            # 提取出生日期
            birth_date_str = self.id_card[6:14]
            self._birthday = datetime.strptime(birth_date_str, '%Y%m%d').date()

            # 计算年龄
            today = date.today()
            self._age = today.year - self._birthday.year - (
                        (today.month, today.day) < (self._birthday.month, self._birthday.day))

            # 从身份证第17位判断性别
            if self.gender is None:
                gender_digit = int(self.id_card[16])
                self.gender = gender_digit % 2 == 1  # 奇数为男，偶数为女

        except ValueError:
            # 身份证号码格式错误
            pass

    @property
    def age(self) -> int:
        """获取计算得到的年龄"""
        return self._age

    @property
    def birthday(self) -> date:
        """获取从身份证提取的出生日期"""
        return self._birthday

    def to_dict(self) -> dict:
        """将学生对象转换为字典格式"""
        return {
            'name': self.name,
            'id_card': self.id_card,
            'stu_id': self.stu_id,
            'gender': self.gender,
            'height': self.height,
            'weight': self.weight,
            'enrollment_date': str(self.enrollment_date) if self.enrollment_date else None,
            'class_name': self.class_name,
            'major': self.major,
            'email': self.email,
            'phone': self.phone,
            'age': self.age,
            'birthday': str(self.birthday) if self.birthday else None
        }