from typing import List, Optional
from datetime import datetime
from pydantic import BaseModel, Field, validator

class User(BaseModel):
    """用戶數(shù)據(jù)模型"""
    id: int
    username: str
    email: str
    age: Optional[int] = None
    is_active: bool = True
    created_at: datetime = Field(default_factory=datetime.now)
    tags: List[str] = []

from pydantic import BaseModel, Field, conint, constr
from typing import Optional

class Product(BaseModel):
    """產(chǎn)品數(shù)據(jù)模型"""
    id: int = Field(..., gt=0, description="產(chǎn)品ID，必須大于0")
    name: constr(min_length=1, max_length=100)  # 字符串長度約束
    price: float = Field(..., gt=0, le=10000, description="價(jià)格范圍0-10000")
    stock: conint(ge=0) = 0  # 整數(shù)約束，大于等于0
    category: Optional[str] = Field(None, regex=r"^[A-Z][a-z]+$")
    
    # 使用Field的更多參數(shù)
    description: str = Field(
        "",
        max_length=500,
        title="產(chǎn)品描述",
        description="產(chǎn)品的詳細(xì)描述信息"
    )

from pydantic import BaseModel, validator
from typing import List

class Order(BaseModel):
    """訂單數(shù)據(jù)模型"""
    items: List[str]
    quantities: List[int]
    total_amount: float
    
    @validator('quantities')
    def validate_quantities(cls, v, values):
        """驗(yàn)證數(shù)量列表"""
        if len(v) != len(values.get('items', [])):
            raise ValueError('數(shù)量列表與商品列表長度必須一致')
        if any(q <= 0 for q in v):
            raise ValueError('所有商品數(shù)量必須大于0')
        return v
    
    @validator('total_amount')
    def validate_total_amount(cls, v, values):
        """驗(yàn)證總金額"""
        quantities = values.get('quantities', [])
        # 模擬計(jì)算：假設(shè)每個(gè)商品單價(jià)為10
        calculated_total = sum(q * 10 for q in quantities)
        if abs(v - calculated_total) > 0.01:  # 允許微小誤差
            raise ValueError(f'總金額計(jì)算錯(cuò)誤，應(yīng)為{calculated_total}')
        return v

from pydantic import BaseModel, root_validator
from typing import Dict, Any

class RegistrationForm(BaseModel):
    """注冊表單模型"""
    username: str
    password: str
    confirm_password: str
    email: str
    
    @root_validator(pre=True)
    def validate_all_fields_present(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        """驗(yàn)證所有必填字段都存在"""
        required_fields = ['username', 'password', 'confirm_password', 'email']
        missing = [field for field in required_fields if field not in values]
        if missing:
            raise ValueError(f'缺少必填字段: {missing}')
        return values
    
    @root_validator
    def validate_passwords_match(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        """驗(yàn)證兩次輸入的密碼是否一致"""
        password = values.get('password')
        confirm_password = values.get('confirm_password')
        
        if password and confirm_password and password != confirm_password:
            raise ValueError('兩次輸入的密碼不一致')
        
        # 密碼強(qiáng)度驗(yàn)證
        if len(password) < 8:
            raise ValueError('密碼長度至少8位')
        if not any(c.isupper() for c in password):
            raise ValueError('密碼必須包含至少一個(gè)大寫字母')
        if not any(c.isdigit() for c in password):
            raise ValueError('密碼必須包含至少一個(gè)數(shù)字')
        
        return values

from typing import List, Optional
from pydantic import BaseModel, Field

class Address(BaseModel):
    """地址模型"""
    street: str
    city: str
    state: str
    zip_code: str
    country: str = "中國"
    
    class Config:
        schema_extra = {
            "example": {
                "street": "人民路123號",
                "city": "北京",
                "state": "北京",
                "zip_code": "100000"
            }
        }

class ContactInfo(BaseModel):
    """聯(lián)系信息模型"""
    phone: str = Field(..., regex=r'^1[3-9]\d{9}$')
    email: str
    address: Address

class Company(BaseModel):
    """公司模型"""
    name: str
    tax_id: str = Field(..., min_length=15, max_length=20)
    contacts: List[ContactInfo]
    headquarters: Optional[Address] = None
    
    def get_primary_contact(self) -> Optional[ContactInfo]:
        """獲取主要聯(lián)系人"""
        return self.contacts[0] if self.contacts else None

from pydantic import BaseModel, Field
from datetime import datetime
from typing import Optional

class BaseEntity(BaseModel):
    """基礎(chǔ)實(shí)體模型"""
    id: int = Field(..., gt=0)
    created_at: datetime = Field(default_factory=datetime.now)
    updated_at: Optional[datetime] = None
    is_deleted: bool = False
    
    class Config:
        """模型配置"""
        validate_assignment = True  # 啟用賦值驗(yàn)證
        anystr_strip_whitespace = True  # 自動去除字符串空格

class Customer(BaseEntity):
    """客戶模型，繼承自BaseEntity"""
    name: str
    email: str
    phone: Optional[str] = None
    loyalty_points: int = Field(0, ge=0)
    
    def add_points(self, points: int) -> None:
        """添加積分"""
        if points > 0:
            self.loyalty_points += points
    
    class Config(BaseEntity.Config):
        """繼承基礎(chǔ)配置并擴(kuò)展"""
        schema_extra = {
            "example": {
                "id": 1,
                "name": "張三",
                "email": "zhangsan@example.com",
                "phone": "13800138000"
            }
        }

from typing import TypeVar, Generic, List, Optional
from pydantic import BaseModel, Field
from pydantic.generics import GenericModel

T = TypeVar('T')

class PaginationParams(BaseModel):
    """分頁參數(shù)"""
    page: int = Field(1, gt=0)
    size: int = Field(10, gt=0, le=100)

class PaginatedResponse(GenericModel, Generic[T]):
    """分頁響應(yīng)泛型模型"""
    items: List[T]
    total: int
    page: int
    size: int
    pages: int
    
    @classmethod
    def create(
        cls, 
        items: List[T], 
        total: int, 
        params: PaginationParams
    ) -> 'PaginatedResponse[T]':
        """創(chuàng)建分頁響應(yīng)"""
        pages = (total + params.size - 1) // params.size
        return cls(
            items=items,
            total=total,
            page=params.page,
            size=params.size,
            pages=pages
        )

class ApiResponse(GenericModel, Generic[T]):
    """API響應(yīng)泛型模型"""
    success: bool
    data: Optional[T] = None
    message: Optional[str] = None
    error_code: Optional[str] = None
    
    @classmethod
    def success_response(cls, data: T) -> 'ApiResponse[T]':
        """成功響應(yīng)"""
        return cls(success=True, data=data)
    
    @classmethod
    def error_response(
        cls, 
        message: str, 
        error_code: str = "UNKNOWN_ERROR"
    ) -> 'ApiResponse[None]':
        """錯(cuò)誤響應(yīng)"""
        return cls(
            success=False, 
            message=message, 
            error_code=error_code
        )

from pydantic import BaseModel, Field
from datetime import datetime
from typing import Optional

class ConfigExample(BaseModel):
    """配置示例模型"""
    sensitive_data: str
    normal_data: str
    created_at: datetime
    
    class Config:
        # 序列化配置
        json_encoders = {
            datetime: lambda dt: dt.strftime('%Y-%m-%d %H:%M:%S')
        }
        
        # 字段別名
        fields = {
            'sensitive_data': {'exclude': True},  # 從序列化中排除
            'normal_data': {'alias': 'data'}  # 使用別名
        }
        
        # 驗(yàn)證配置
        validate_assignment = True  # 賦值時(shí)驗(yàn)證
        extra = 'forbid'  # 禁止額外字段
        anystr_lower = True  # 自動轉(zhuǎn)換為小寫
        
        # ORM模式
        orm_mode = True

# 使用配置的示例
example = ConfigExample(
    sensitive_data="secret",
    normal_data="Hello World",
    created_at=datetime.now()
)

# 序列化為字典（排除敏感字段）
print(example.dict(exclude={'sensitive_data'}))

import json
from datetime import datetime
from typing import List
from pydantic import BaseModel, Field

class Book(BaseModel):
    """書籍模型"""
    title: str
    author: str
    isbn: str = Field(..., regex=r'^\d{13}$')
    price: float = Field(..., gt=0)
    published_date: datetime
    categories: List[str] = []
    
    class Config:
        json_encoders = {
            datetime: lambda dt: dt.isoformat()
        }
        schema_extra = {
            "example": {
                "title": "Python編程從入門到實(shí)踐",
                "author": "Eric Matthes",
                "isbn": "9787115428028",
                "price": 89.00,
                "published_date": "2020-10-01T00:00:00",
                "categories": ["編程", "Python"]
            }
        }

# 創(chuàng)建實(shí)例
book = Book(
    title="Python高級編程",
    author="Luciano Ramalho",
    isbn="9787115390592",
    price=99.00,
    published_date=datetime(2021, 5, 1),
    categories=["編程", "Python", "高級"]
)

# 序列化為字典
book_dict = book.dict()
print("字典格式:", book_dict)

# 序列化為JSON
book_json = book.json()
print("JSON格式:", book_json)

# 序列化時(shí)排除字段
book_dict_excluded = book.dict(exclude={'price'})
print("排除價(jià)格字段:", book_dict_excluded)

# 只包含特定字段
book_dict_included = book.dict(include={'title', 'author'})
print("僅包含標(biāo)題和作者:", book_dict_included)

# 反序列化
json_data = '''
{
    "title": "流暢的Python",
    "author": "Luciano Ramalho",
    "isbn": "9787115454157",
    "price": 109.00,
    "published_date": "2022-03-01T00:00:00",
    "categories": ["編程", "Python"]
}
'''

parsed_book = Book.parse_raw(json_data)
print("反序列化結(jié)果:", parsed_book)

# 從字典創(chuàng)建
data_dict = {
    "title": "Python Cookbook",
    "author": "David Beazley",
    "isbn": "9781449340377",
    "price": 118.00,
    "published_date": "2020-08-01T00:00:00"
}
book_from_dict = Book(**data_dict)
print("從字典創(chuàng)建:", book_from_dict)

from typing import Dict, Any, List
from pydantic import BaseModel, Field

class Product(BaseModel):
    """產(chǎn)品模型，演示高級序列化"""
    id: int
    name: str
    price: float
    inventory: int
    metadata: Dict[str, Any] = Field(default_factory=dict)
    
    def to_api_response(self) -> Dict[str, Any]:
        """轉(zhuǎn)換為API響應(yīng)格式"""
        return {
            "product": {
                "id": self.id,
                "name": self.name,
                "price": self.price,
                "in_stock": self.inventory > 0,
                "inventory": self.inventory if self.inventory > 10 else "低庫存"
            },
            "metadata": self.metadata
        }
    
    @classmethod
    def from_api_request(cls, data: Dict[str, Any]) -> 'Product':
        """從API請求數(shù)據(jù)創(chuàng)建實(shí)例"""
        # 預(yù)處理數(shù)據(jù)
        processed_data = data.copy()
        if 'price' in processed_data:
            # 確保價(jià)格是浮點(diǎn)數(shù)
            processed_data['price'] = float(processed_data['price'])
        
        return cls(**processed_data)

class ProductCatalog(BaseModel):
    """產(chǎn)品目錄"""
    products: List[Product]
    total_value: float = Field(0, description="庫存總價(jià)值")
    
    @classmethod
    def from_products(cls, products: List[Product]) -> 'ProductCatalog':
        """從產(chǎn)品列表創(chuàng)建目錄"""
        total_value = sum(p.price * p.inventory for p in products)
        return cls(products=products, total_value=total_value)
    
    def to_summary_dict(self) -> Dict[str, Any]:
        """轉(zhuǎn)換為摘要字典"""
        return {
            "product_count": len(self.products),
            "total_value": round(self.total_value, 2),
            "average_price": round(
                self.total_value / sum(p.inventory for p in self.products), 
                2
            ) if self.products else 0
        }

from typing import Optional, List
from datetime import datetime
from pydantic import BaseModel, Field, validator
from enum import Enum

class OrderStatus(str, Enum):
    """訂單狀態(tài)枚舉"""
    PENDING = "pending"
    PROCESSING = "processing"
    SHIPPED = "shipped"
    DELIVERED = "delivered"
    CANCELLED = "cancelled"

class OrderItem(BaseModel):
    """訂單項(xiàng)"""
    product_id: int = Field(..., gt=0)
    quantity: int = Field(..., gt=0, le=100)
    unit_price: float = Field(..., gt=0)
    
    @property
    def total_price(self) -> float:
        """計(jì)算總價(jià)"""
        return self.quantity * self.unit_price

class CreateOrderRequest(BaseModel):
    """創(chuàng)建訂單請求"""
    customer_id: int = Field(..., gt=0)
    items: List[OrderItem] = Field(..., min_items=1)
    shipping_address: str
    notes: Optional[str] = None
    
    @validator('items')
    def validate_items(cls, v):
        """驗(yàn)證訂單項(xiàng)"""
        # 檢查是否有重復(fù)的商品ID
        product_ids = [item.product_id for item in v]
        if len(product_ids) != len(set(product_ids)):
            raise ValueError('訂單中存在重復(fù)的商品')
        return v
    
    @property
    def total_amount(self) -> float:
        """計(jì)算訂單總金額"""
        return sum(item.total_price for item in self.items)

class OrderResponse(BaseModel):
    """訂單響應(yīng)"""
    order_id: int
    customer_id: int
    items: List[OrderItem]
    status: OrderStatus
    total_amount: float
    created_at: datetime
    estimated_delivery: Optional[datetime] = None
    
    class Config:
        json_encoders = {
            datetime: lambda dt: dt.isoformat()
        }
        schema_extra = {
            "example": {
                "order_id": 12345,
                "customer_id": 1001,
                "status": "processing",
                "total_amount": 299.99,
                "created_at": "2024-01-15T10:30:00"
            }
        }

class OrderService:
    """訂單服務(wù)類"""
    
    @staticmethod
    def create_order(request: CreateOrderRequest) -> OrderResponse:
        """創(chuàng)建訂單"""
        # 模擬訂單創(chuàng)建邏輯
        order_id = 12345  # 實(shí)際應(yīng)從數(shù)據(jù)庫生成
        
        # 計(jì)算預(yù)計(jì)送達(dá)時(shí)間（3天后）
        from datetime import timedelta
        estimated_delivery = datetime.now() + timedelta(days=3)
        
        return OrderResponse(
            order_id=order_id,
            customer_id=request.customer_id,
            items=request.items,
            status=OrderStatus.PENDING,
            total_amount=request.total_amount,
            created_at=datetime.now(),
            estimated_delivery=estimated_delivery
        )
    
    @staticmethod
    def validate_order_data(data: dict) -> Optional[str]:
        """驗(yàn)證訂單數(shù)據(jù)，返回錯(cuò)誤信息或None"""
        try:
            CreateOrderRequest(**data)
            return None
        except Exception as e:
            return str(e)

from typing import Optional, List
from datetime import datetime
from pydantic import BaseModel, Field, validator
from sqlalchemy import Column, Integer, String, Float, DateTime, Boolean
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session

# SQLAlchemy基礎(chǔ)類
Base = declarative_base()

# SQLAlchemy模型
class ProductDB(Base):
    """產(chǎn)品數(shù)據(jù)庫模型"""
    __tablename__ = 'products'
    
    id = Column(Integer, primary_key=True)
    name = Column(String(100), nullable=False)
    description = Column(String(500))
    price = Column(Float, nullable=False)
    stock = Column(Integer, default=0)
    category = Column(String(50))
    is_active = Column(Boolean, default=True)
    created_at = Column(DateTime, default=datetime.now)
    updated_at = Column(DateTime, onupdate=datetime.now)

# Pydantic模型
class ProductBase(BaseModel):
    """產(chǎn)品基礎(chǔ)模型"""
    name: str = Field(..., max_length=100)
    description: Optional[str] = Field(None, max_length=500)
    price: float = Field(..., gt=0)
    stock: int = Field(0, ge=0)
    category: Optional[str] = Field(None, max_length=50)
    
    @validator('price')
    def validate_price(cls, v):
        """價(jià)格驗(yàn)證"""
        if v > 1000000:
            raise ValueError('價(jià)格過高')
        return round(v, 2)

class ProductCreate(ProductBase):
    """創(chuàng)建產(chǎn)品模型"""
    pass

class ProductUpdate(BaseModel):
    """更新產(chǎn)品模型"""
    name: Optional[str] = Field(None, max_length=100)
    description: Optional[str] = Field(None, max_length=500)
    price: Optional[float] = Field(None, gt=0)
    stock: Optional[int] = Field(None, ge=0)
    category: Optional[str] = Field(None, max_length=50)
    is_active: Optional[bool] = None

class ProductResponse(ProductBase):
    """產(chǎn)品響應(yīng)模型"""
    id: int
    is_active: bool
    created_at: datetime
    updated_at: Optional[datetime] = None
    
    class Config:
        orm_mode = True  # 啟用ORM模式

class ProductRepository:
    """產(chǎn)品倉庫類"""
    
    @staticmethod
    def create(db: Session, product: ProductCreate) -> ProductDB:
        """創(chuàng)建產(chǎn)品"""
        db_product = ProductDB(**product.dict())
        db.add(db_product)
        db.commit()
        db.refresh(db_product)
        return db_product
    
    @staticmethod
    def get(db: Session, product_id: int) -> Optional[ProductDB]:
        """獲取產(chǎn)品"""
        return db.query(ProductDB).filter(
            ProductDB.id == product_id,
            ProductDB.is_active == True
        ).first()
    
    @staticmethod
    def update(
        db: Session, 
        product_id: int, 
        update_data: ProductUpdate
    ) -> Optional[ProductDB]:
        """更新產(chǎn)品"""
        db_product = ProductRepository.get(db, product_id)
        if not db_product:
            return None
        
        # 更新字段
        update_dict = update_data.dict(exclude_unset=True)
        for key, value in update_dict.items():
            setattr(db_product, key, value)
        
        db_product.updated_at = datetime.now()
        db.commit()
        db.refresh(db_product)
        return db_product
    
    @staticmethod
    def to_pydantic(db_product: ProductDB) -> ProductResponse:
        """轉(zhuǎn)換為Pydantic響應(yīng)模型"""
        return ProductResponse.from_orm(db_product)

"""
Pydantic數(shù)據(jù)驗(yàn)證與序列化完整示例
演示用戶管理系統(tǒng)中的數(shù)據(jù)處理
"""

import json
from datetime import datetime, date
from typing import List, Optional, Dict, Any
from enum import Enum
from uuid import uuid4
from pydantic import (
    BaseModel, 
    Field, 
    validator, 
    root_validator,
    EmailStr,
    HttpUrl
)
from pydantic.generics import GenericModel
from typing import Generic, TypeVar

# 定義泛型類型
T = TypeVar('T')

# 枚舉定義
class UserRole(str, Enum):
    """用戶角色枚舉"""
    ADMIN = "admin"
    USER = "user"
    GUEST = "guest"
    MODERATOR = "moderator"

class AccountStatus(str, Enum):
    """賬戶狀態(tài)枚舉"""
    ACTIVE = "active"
    INACTIVE = "inactive"
    SUSPENDED = "suspended"
    BANNED = "banned"

# 基礎(chǔ)模型
class TimestampMixin(BaseModel):
    """時(shí)間戳混合類"""
    created_at: datetime = Field(default_factory=datetime.now)
    updated_at: Optional[datetime] = None
    
    class Config:
        validate_assignment = True

# 地址模型
class Address(BaseModel):
    """地址信息"""
    street: str = Field(..., max_length=200)
    city: str = Field(..., max_length=100)
    state: str = Field(..., max_length=50)
    zip_code: str = Field(..., regex=r'^\d{6}$')
    country: str = "中國"
    
    @property
    def full_address(self) -> str:
        """獲取完整地址"""
        return f"{self.country}{self.state}{self.city}{self.street}，郵編：{self.zip_code}"

# 聯(lián)系信息模型
class ContactInfo(BaseModel):
    """聯(lián)系信息"""
    email: EmailStr
    phone: Optional[str] = Field(None, regex=r'^1[3-9]\d{9}$')
    website: Optional[HttpUrl] = None
    
    @validator('phone')
    def validate_phone(cls, v):
        """驗(yàn)證手機(jī)號"""
        if v and not v.startswith('1'):
            raise ValueError('手機(jī)號格式不正確')
        return v

# 用戶基礎(chǔ)模型
class UserBase(TimestampMixin):
    """用戶基礎(chǔ)信息"""
    username: str = Field(
        ..., 
        min_length=3, 
        max_length=50,
        regex=r'^[a-zA-Z][a-zA-Z0-9_]*$',
        description="用戶名，只能包含字母、數(shù)字和下劃線"
    )
    display_name: str = Field(..., max_length=100)
    email: EmailStr
    birth_date: Optional[date] = None
    role: UserRole = UserRole.USER
    status: AccountStatus = AccountStatus.ACTIVE
    
    @validator('birth_date')
    def validate_birth_date(cls, v):
        """驗(yàn)證出生日期"""
        if v:
            if v > date.today():
                raise ValueError('出生日期不能在未來')
            # 檢查年齡是否合理（假設(shè)用戶年齡在0-150歲之間）
            age = (date.today() - v).days // 365
            if age > 150:
                raise ValueError('年齡不合理')
        return v

# 用戶創(chuàng)建模型
class UserCreate(UserBase):
    """創(chuàng)建用戶模型"""
    password: str = Field(..., min_length=8)
    confirm_password: str
    
    @root_validator
    def validate_passwords(cls, values):
        """驗(yàn)證密碼"""
        password = values.get('password')
        confirm_password = values.get('confirm_password')
        
        if password and confirm_password and password != confirm_password:
            raise ValueError('兩次輸入的密碼不一致')
        
        # 密碼強(qiáng)度檢查
        if password:
            if not any(c.isupper() for c in password):
                raise ValueError('密碼必須包含至少一個(gè)大寫字母')
            if not any(c.isdigit() for c in password):
                raise ValueError('密碼必須包含至少一個(gè)數(shù)字')
            if not any(c in '!@#$%^&*()_+-=[]{}|;:,.<>?`~' for c in password):
                raise ValueError('密碼必須包含至少一個(gè)特殊字符')
        
        return values

# 用戶更新模型
class UserUpdate(BaseModel):
    """更新用戶模型"""
    display_name: Optional[str] = Field(None, max_length=100)
    email: Optional[EmailStr] = None
    birth_date: Optional[date] = None
    role: Optional[UserRole] = None
    status: Optional[AccountStatus] = None
    
    class Config:
        extra = 'forbid'  # 禁止額外字段

# 用戶完整模型
class User(UserBase):
    """用戶完整模型"""
    id: str = Field(default_factory=lambda: str(uuid4()))
    addresses: List[Address] = []
    contact_info: ContactInfo
    metadata: Dict[str, Any] = Field(default_factory=dict)
    last_login: Optional[datetime] = None
    login_count: int = 0
    
    @property
    def age(self) -> Optional[int]:
        """計(jì)算年齡"""
        if self.birth_date:
            today = date.today()
            return today.year - self.birth_date.year - (
                (today.month, today.day) < (self.birth_date.month, self.birth_date.day)
            )
        return None
    
    def to_summary_dict(self) -> Dict[str, Any]:
        """轉(zhuǎn)換為摘要字典"""
        return {
            'id': self.id,
            'username': self.username,
            'display_name': self.display_name,
            'email': self.email,
            'role': self.role,
            'status': self.status,
            'age': self.age,
            'address_count': len(self.addresses)
        }
    
    def record_login(self) -> None:
        """記錄登錄"""
        self.last_login = datetime.now()
        self.login_count += 1
        self.updated_at = datetime.now()

# API響應(yīng)模型
class ApiResponse(GenericModel, Generic[T]):
    """通用API響應(yīng)"""
    success: bool
    data: Optional[T] = None
    message: Optional[str] = None
    error_code: Optional[str] = None
    timestamp: datetime = Field(default_factory=datetime.now)
    
    class Config:
        json_encoders = {
            datetime: lambda dt: dt.isoformat()
        }
    
    @classmethod
    def success(cls, data: T, message: str = "操作成功") -> 'ApiResponse[T]':
        """成功響應(yīng)"""
        return cls(success=True, data=data, message=message)
    
    @classmethod
    def error(
        cls, 
        message: str, 
        error_code: str = "INTERNAL_ERROR"
    ) -> 'ApiResponse[None]':
        """錯(cuò)誤響應(yīng)"""
        return cls(success=False, message=message, error_code=error_code)

# 分頁模型
class PaginationParams(BaseModel):
    """分頁參數(shù)"""
    page: int = Field(1, gt=0)
    size: int = Field(10, gt=0, le=100)
    sort_by: Optional[str] = None
    sort_order: Optional[str] = Field(None, regex=r'^(asc|desc)$')

class PaginatedResponse(GenericModel, Generic[T]):
    """分頁響應(yīng)"""
    items: List[T]
    total: int
    page: int
    size: int
    pages: int
    has_next: bool
    has_prev: bool
    
    @classmethod
    def create(
        cls,
        items: List[T],
        total: int,
        params: PaginationParams
    ) -> 'PaginatedResponse[T]':
        """創(chuàng)建分頁響應(yīng)"""
        pages = (total + params.size - 1) // params.size
        has_next = params.page < pages
        has_prev = params.page > 1
        
        return cls(
            items=items,
            total=total,
            page=params.page,
            size=params.size,
            pages=pages,
            has_next=has_next,
            has_prev=has_prev
        )

# 用戶服務(wù)類
class UserService:
    """用戶服務(wù)"""
    
    def __init__(self):
        self.users: Dict[str, User] = {}
    
    def create_user(self, user_data: UserCreate) -> ApiResponse[User]:
        """創(chuàng)建用戶"""
        try:
            # 檢查用戶名是否已存在
            if any(u.username == user_data.username for u in self.users.values()):
                return ApiResponse.error("用戶名已存在", "USERNAME_EXISTS")
            
            # 檢查郵箱是否已存在
            if any(u.email == user_data.email for u in self.users.values()):
                return ApiResponse.error("郵箱已存在", "EMAIL_EXISTS")
            
            # 創(chuàng)建用戶（排除密碼字段）
            user_dict = user_data.dict(exclude={'password', 'confirm_password'})
            user = User(**user_dict)
            
            # 添加聯(lián)系信息（示例）
            user.contact_info = ContactInfo(email=user_data.email)
            
            # 保存用戶
            self.users[user.id] = user
            
            return ApiResponse.success(user, "用戶創(chuàng)建成功")
            
        except Exception as e:
            return ApiResponse.error(f"創(chuàng)建用戶失敗: {str(e)}")
    
    def get_user(self, user_id: str) -> ApiResponse[User]:
        """獲取用戶"""
        user = self.users.get(user_id)
        if not user:
            return ApiResponse.error("用戶不存在", "USER_NOT_FOUND")
        return ApiResponse.success(user)
    
    def update_user(
        self, 
        user_id: str, 
        update_data: UserUpdate
    ) -> ApiResponse[User]:
        """更新用戶"""
        user = self.users.get(user_id)
        if not user:
            return ApiResponse.error("用戶不存在", "USER_NOT_FOUND")
        
        try:
            # 更新字段
            update_dict = update_data.dict(exclude_unset=True)
            for key, value in update_dict.items():
                setattr(user, key, value)
            
            user.updated_at = datetime.now()
            
            return ApiResponse.success(user, "用戶更新成功")
            
        except Exception as e:
            return ApiResponse.error(f"更新用戶失敗: {str(e)}")
    
    def list_users(
        self, 
        params: PaginationParams
    ) -> ApiResponse[PaginatedResponse[User]]:
        """用戶列表"""
        try:
            # 獲取所有用戶
            all_users = list(self.users.values())
            
            # 排序
            if params.sort_by:
                reverse = params.sort_order == 'desc'
                all_users.sort(
                    key=lambda u: getattr(u, params.sort_by, u.username),
                    reverse=reverse
                )
            
            # 分頁
            start = (params.page - 1) * params.size
            end = start + params.size
            paginated_users = all_users[start:end]
            
            # 創(chuàng)建分頁響應(yīng)
            paginated_response = PaginatedResponse.create(
                items=paginated_users,
                total=len(all_users),
                params=params
            )
            
            return ApiResponse.success(paginated_response)
            
        except Exception as e:
            return ApiResponse.error(f"獲取用戶列表失敗: {str(e)}")

# 演示函數(shù)
def demonstrate_pydantic_features():
    """演示Pydantic功能"""
    print("=" * 60)
    print("Pydantic數(shù)據(jù)驗(yàn)證與序列化演示")
    print("=" * 60)
    
    # 1. 創(chuàng)建用戶
    print("\n1. 創(chuàng)建用戶")
    user_service = UserService()
    
    # 正確的用戶數(shù)據(jù)
    valid_user_data = {
        "username": "john_doe",
        "display_name": "John Doe",
        "email": "john@example.com",
        "password": "SecurePass123!",
        "confirm_password": "SecurePass123!",
        "birth_date": "1990-01-01",
        "role": "user",
        "status": "active"
    }
    
    create_response = user_service.create_user(UserCreate(**valid_user_data))
    if create_response.success:
        print(f"用戶創(chuàng)建成功: {create_response.data.username}")
        
        # 2. 獲取用戶
        print("\n2. 獲取用戶")
        user_id = create_response.data.id
        get_response = user_service.get_user(user_id)
        
        if get_response.success:
            user = get_response.data
            print(f"用戶信息: {user.to_summary_dict()}")
            
            # 3. 序列化為JSON
            print("\n3. 序列化為JSON")
            user_json = user.json(indent=2)
            print("用戶JSON表示:")
            print(user_json)
            
            # 4. 反序列化
            print("\n4. 反序列化")
            parsed_user = User.parse_raw(user_json)
            print(f"反序列化成功: {parsed_user.username}")
            
            # 5. 更新用戶
            print("\n5. 更新用戶")
            update_data = UserUpdate(
                display_name="John Smith",
                role=UserRole.MODERATOR
            )
            update_response = user_service.update_user(user_id, update_data)
            
            if update_response.success:
                print(f"用戶更新成功: {update_response.data.display_name}")
            
            # 6. 用戶列表分頁
            print("\n6. 用戶列表分頁")
            pagination_params = PaginationParams(page=1, size=5)
            list_response = user_service.list_users(pagination_params)
            
            if list_response.success:
                paginated_data = list_response.data
                print(f"總用戶數(shù): {paginated_data.total}")
                print(f"當(dāng)前頁: {paginated_data.page}/{paginated_data.pages}")
                print(f"每頁大小: {paginated_data.size}")
                
        # 7. 錯(cuò)誤處理演示
        print("\n7. 錯(cuò)誤處理演示")
        
        # 無效的用戶名
        print("\n嘗試使用無效用戶名:")
        invalid_username_data = valid_user_data.copy()
        invalid_username_data['username'] = "123invalid"  # 以數(shù)字開頭
        
        try:
            UserCreate(**invalid_username_data)
        except Exception as e:
            print(f"錯(cuò)誤: {e}")
        
        # 密碼不匹配
        print("\n嘗試使用不匹配的密碼:")
        invalid_password_data = valid_user_data.copy()
        invalid_password_data['confirm_password'] = "DifferentPass123!"
        
        try:
            UserCreate(**invalid_password_data)
        except Exception as e:
            print(f"錯(cuò)誤: {e}")
        
        # 弱密碼
        print("\n嘗試使用弱密碼:")
        weak_password_data = valid_user_data.copy()
        weak_password_data['password'] = weak_password_data['confirm_password'] = "weak"
        
        try:
            UserCreate(**weak_password_data)
        except Exception as e:
            print(f"錯(cuò)誤: {e}")
    
    print("\n" + "=" * 60)
    print("演示完成")
    print("=" * 60)

if __name__ == "__main__":
    # 運(yùn)行演示
    demonstrate_pydantic_features()