"""
验证服务

提供各种边界条件的验证功能。
"""

import re
from typing import Dict, Any, Tuple, Optional


class ValidationService:
    """验证服务类"""
    
    # 验证规则常量
    USERNAME_MIN_LENGTH = 3
    USERNAME_MAX_LENGTH = 20
    USERNAME_PATTERN = re.compile(r'^[a-zA-Z0-9_]+$')
    
    EMAIL_PATTERN = re.compile(r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$')
    
    ROLE_NAME_MIN_LENGTH = 1
    ROLE_NAME_MAX_LENGTH = 50
    ROLE_CODE_MIN_LENGTH = 1
    ROLE_CODE_MAX_LENGTH = 30
    ROLE_CODE_PATTERN = re.compile(r'^[a-zA-Z0-9_]+$')
    
    @staticmethod
    def validate_username(username: str) -> Tuple[bool, Optional[str]]:
        """
        验证用户名
        
        Returns:
            (is_valid, error_message)
        """
        if not username:
            return False, "用户名不能为空"
        
        if len(username) < ValidationService.USERNAME_MIN_LENGTH:
            return False, f"用户名长度不能少于{ValidationService.USERNAME_MIN_LENGTH}个字符"
        
        if len(username) > ValidationService.USERNAME_MAX_LENGTH:
            return False, f"用户名长度不能超过{ValidationService.USERNAME_MAX_LENGTH}个字符"
        
        if not ValidationService.USERNAME_PATTERN.match(username):
            return False, "用户名只能包含字母、数字和下划线"
        
        return True, None
    
    @staticmethod
    def validate_email(email: str) -> Tuple[bool, Optional[str]]:
        """
        验证邮箱格式
        
        Returns:
            (is_valid, error_message)
        """
        if not email:
            return False, "邮箱不能为空"
        
        if not ValidationService.EMAIL_PATTERN.match(email):
            return False, "邮箱格式不正确"
        
        return True, None
    
    @staticmethod
    def validate_role_name(name: str) -> Tuple[bool, Optional[str]]:
        """
        验证角色名称
        
        Returns:
            (is_valid, error_message)
        """
        if not name:
            return False, "角色名称不能为空"
        
        if len(name) > ValidationService.ROLE_NAME_MAX_LENGTH:
            return False, f"角色名称长度不能超过{ValidationService.ROLE_NAME_MAX_LENGTH}个字符"
        
        return True, None
    
    @staticmethod
    def validate_role_code(code: str) -> Tuple[bool, Optional[str]]:
        """
        验证角色编码
        
        Returns:
            (is_valid, error_message)
        """
        if not code:
            return False, "角色编码不能为空"
        
        if len(code) > ValidationService.ROLE_CODE_MAX_LENGTH:
            return False, f"角色编码长度不能超过{ValidationService.ROLE_CODE_MAX_LENGTH}个字符"
        
        if not ValidationService.ROLE_CODE_PATTERN.match(code):
            return False, "角色编码只能包含字母、数字和下划线"
        
        return True, None
    
    @staticmethod
    def validate_user_data(data: Dict[str, Any]) -> Dict[str, Any]:
        """
        验证用户数据
        
        Returns:
            {"valid": bool, "errors": Dict[str, str]}
        """
        errors = {}
        
        # 验证用户名
        if "username" in data:
            is_valid, error = ValidationService.validate_username(data["username"])
            if not is_valid:
                errors["username"] = error
        
        # 验证邮箱
        if "email" in data:
            is_valid, error = ValidationService.validate_email(data["email"])
            if not is_valid:
                errors["email"] = error
        
        return {
            "valid": len(errors) == 0,
            "errors": errors
        }
    
    @staticmethod
    def validate_role_data(data: Dict[str, Any]) -> Dict[str, Any]:
        """
        验证角色数据
        
        Returns:
            {"valid": bool, "errors": Dict[str, str]}
        """
        errors = {}
        
        # 验证角色名称
        if "name" in data:
            is_valid, error = ValidationService.validate_role_name(data["name"])
            if not is_valid:
                errors["name"] = error
        
        # 验证角色编码
        if "code" in data:
            is_valid, error = ValidationService.validate_role_code(data["code"])
            if not is_valid:
                errors["code"] = error
        
        return {
            "valid": len(errors) == 0,
            "errors": errors
        }


# 全局验证服务实例
validation_service = ValidationService()