from datetime import date, datetime
from typing import Dict, Any, List, Optional, Tuple
from data_access import StudentDataAccess


class IDCardValidator:
    """身份证验证工具类"""

    @staticmethod
    def validate_id_card(id_card: str) -> Tuple[bool, str]:
        """验证身份证号有效性"""
        # 基本格式验证
        if len(id_card) != 18:
            return False, "身份证号必须为18位"

        # 前17位必须是数字，最后一位可以是数字或X
        if not (id_card[:-1].isdigit() and (id_card[-1].isdigit() or id_card[-1].upper() == 'X')):
            return False, "身份证号格式不正确，前17位必须是数字，最后一位可以是数字或X"

        # 验证出生日期
        birth_date = id_card[6:14]
        if not IDCardValidator.validate_birth_date(birth_date):
            return False, "身份证号中的出生日期无效"

        # 验证校验码
        if not IDCardValidator.validate_check_code(id_card):
            return False, "身份证号校验码不正确"

        return True, "身份证号有效"

    @staticmethod
    def validate_birth_date(birth_date: str) -> bool:
        """验证出生日期是否有效"""
        try:
            # 尝试解析日期
            year = int(birth_date[0:4])
            month = int(birth_date[4:6])
            day = int(birth_date[6:8])

            # 检查日期范围
            if not (1900 <= year <= date.today().year):
                return False
            if not (1 <= month <= 12):
                return False

            # 检查每月天数
            max_day = IDCardValidator.get_days_in_month(year, month)
            if not (1 <= day <= max_day):
                return False

            return True
        except:
            return False

    @staticmethod
    def get_days_in_month(year: int, month: int) -> int:
        """获取某年某月的天数"""
        if month == 2:
            return 29 if IDCardValidator.is_leap_year(year) else 28
        elif month in [4, 6, 9, 11]:
            return 30
        else:
            return 31

    @staticmethod
    def is_leap_year(year: int) -> bool:
        """判断是否为闰年"""
        return (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0)

    @staticmethod
    def validate_check_code(id_card: str) -> bool:
        """验证身份证校验码"""
        # 权重因子
        weight = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2]
        # 校验码对应表
        check_code_map = ['1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2']

        # 计算加权和
        total = sum(int(id_card[i]) * weight[i] for i in range(17))
        # 计算校验码
        calculated_code = check_code_map[total % 11]

        # 比较校验码
        return id_card[-1].upper() == calculated_code

    @staticmethod
    def get_gender(id_card: str) -> str:
        """根据身份证号获取性别"""
        if len(id_card) < 17:
            return "未知"
        gender_num = int(id_card[16])
        return "男" if gender_num % 2 == 1 else "女"

    @staticmethod
    def get_birth_date(id_card: str) -> Optional[date]:
        """从身份证号获取出生日期"""
        if len(id_card) < 14:
            return None
        try:
            birth_str = id_card[6:14]
            return datetime.strptime(birth_str, "%Y%m%d").date()
        except:
            return None

    @staticmethod
    def calculate_age(id_card: str) -> Optional[int]:
        """根据身份证号计算年龄"""
        birth_date = IDCardValidator.get_birth_date(id_card)
        if not birth_date:
            return None

        today = date.today()
        age = today.year - birth_date.year
        # 如果生日还没到，年龄减1
        if (today.month, today.day) < (birth_date.month, birth_date.day):
            age -= 1
        return age


class StudentService:
    def __init__(self, data_access: StudentDataAccess):
        self.data_access = data_access
        self.subject_name = {
            'math': '数学',
            'python': 'Python程序设计',
            'english': '英语',
            'physics': '物理',
            'sum': '总分'
        }

    def validate_id_card(self, id_card: str) -> Tuple[bool, str]:
        """验证身份证号格式"""
        return IDCardValidator.validate_id_card(id_card)

    def is_id_card_exists(self, id_card: str, exclude_id: str = None) -> bool:
        """检查身份证号是否已存在"""
        students = self.data_access.get_all_students()
        for sid, student in students.items():
            if exclude_id and sid == exclude_id:
                continue
            if student['basic_info'].get('id_card', '').upper() == id_card.upper():
                return True
        return False

    def add_student(self, student_info: Dict[str, Any]) -> bool:
        """添加新学生"""
        student_id = student_info['basic_info']['id']

        # 验证学号
        if not student_id.isdigit() or len(student_id) != 8:
            raise ValueError("学号必须为8位数字！")

        # 验证身份证号
        id_card = student_info['basic_info'].get('id_card', '')
        if not id_card:
            raise ValueError("身份证号不能为空！")

        is_valid, msg = self.validate_id_card(id_card)
        if not is_valid:
            raise ValueError(f"身份证号无效: {msg}")

        if self.is_id_card_exists(id_card):
            raise ValueError("该身份证号已存在！")

        # 自动填充性别和出生日期
        student_info['basic_info']['gender'] = IDCardValidator.get_gender(id_card)
        birth_date = IDCardValidator.get_birth_date(id_card)
        if birth_date:
            student_info['basic_info']['birth_date'] = birth_date.strftime("%Y-%m-%d")
            student_info['basic_info']['age'] = IDCardValidator.calculate_age(id_card)

        # 计算总分
        scores = student_info['score']
        scores['sum'] = sum([scores['math'], scores['python'], scores['english'], scores['physics']])

        return self.data_access.add_student(student_id, student_info)

    def update_student(self, student_id: str, student_info: Dict[str, Any]) -> bool:
        """更新学生信息"""
        # 验证身份证号
        id_card = student_info['basic_info'].get('id_card', '')
        if id_card:  # 如果提供了身份证号才验证
            is_valid, msg = self.validate_id_card(id_card)
            if not is_valid:
                raise ValueError(f"身份证号无效: {msg}")
            if self.is_id_card_exists(id_card, exclude_id=student_id):
                raise ValueError("该身份证号已被其他学生使用！")

            # 自动更新性别和出生日期
            student_info['basic_info']['gender'] = IDCardValidator.get_gender(id_card)
            birth_date = IDCardValidator.get_birth_date(id_card)
            if birth_date:
                student_info['basic_info']['birth_date'] = birth_date.strftime("%Y-%m-%d")
                student_info['basic_info']['age'] = IDCardValidator.calculate_age(id_card)

        # 计算总分
        scores = student_info['score']
        scores['sum'] = sum([scores['math'], scores['python'], scores['english'], scores['physics']])

        return self.data_access.update_student(student_id, student_info)

    def delete_student(self, student_id: str) -> bool:
        """删除学生"""
        return self.data_access.delete_student(student_id)

    def get_student(self, student_id: str) -> Dict[str, Any]:
        """获取单个学生信息"""
        return self.data_access.get_student(student_id)

    def get_all_students(self) -> Dict[str, Any]:
        """获取所有学生信息"""
        return self.data_access.get_all_students()

    def search_student_by_id(self, student_id: str) -> Dict[str, Any]:
        """按学号查询学生信息"""
        return self.data_access.get_student(student_id)

    def get_statistics(self) -> Dict[str, float]:
        """获取统计信息"""
        students = self.data_access.get_all_students().values()
        if not students:
            return {}

        total = len(students)
        return {
            'total': total,
            'math_avg': sum(s['score']['math'] for s in students) / total,
            'python_avg': sum(s['score']['python'] for s in students) / total,
            'english_avg': sum(s['score']['english'] for s in students) / total,
            'physics_avg': sum(s['score']['physics'] for s in students) / total,
            'total_avg': sum(s['score']['sum'] for s in students) / total
        }

    def get_sorted_students(self) -> List[Dict[str, Any]]:
        """按总分排序获取学生"""
        students = list(self.data_access.get_all_students().values())
        return sorted(students, key=lambda x: x['score']['sum'], reverse=True)

    def load_data(self):
        pass