from pydantic_settings import BaseSettings
from pydantic import field_validator


class DatabaseConfig(BaseSettings):
    """数据库配置"""
    host: str = "localhost"
    port: int = 3306
    user: str = "root"
    password: str = ""
    name: str = "question_bank"

    @field_validator('port')
    def validate_db_port(cls, value):
        if value < 1024 or value > 65535:
            raise ValueError('数据库端口必须在1024-65535之间')
        return value

    @field_validator('name')
    def validate_db_name(cls, value):
        if not value or len(value) < 2:
            raise ValueError('数据库名称不能为空且至少2个字符')
        return value

    def to_string(self, indent: int = 0) -> str:
        """将配置转换为字符串"""
        indent_str = ' ' * indent
        result = []
        for field_name, field_value in self.__dict__.items():
            result.append(f"{indent_str}{field_name}: {field_value}")
        return '\n'.join(result)