"""
Authentication schemas for request/response validation.
Defines Pydantic models for user registration, login, and token management.
"""
from pydantic import BaseModel, EmailStr, Field
from typing import Optional, TYPE_CHECKING
from datetime import datetime


class UserRegister(BaseModel):
    """User registration request schema."""
    username: str = Field(..., min_length=3, max_length=50, description="用户名，3-50个字符")
    email: EmailStr = Field(..., description="有效的邮箱地址")
    password: str = Field(..., min_length=8, max_length=100, description="密码，至少8个字符")


class UserLogin(BaseModel):
    """User login request schema."""
    username: str = Field(..., description="用户名")
    password: str = Field(..., description="密码")


class UserResponse(BaseModel):
    """User response schema."""
    id: str = Field(..., description="用户ID")
    username: str = Field(..., description="用户名")
    email: str = Field(..., description="邮箱")
    role: str = Field(..., description="用户角色")
    created_at: datetime = Field(..., description="创建时间")
    
    class Config:
        from_attributes = True


class TokenResponse(BaseModel):
    """Token response schema."""
    access_token: str = Field(..., description="访问令牌")
    refresh_token: str = Field(..., description="刷新令牌")
    token_type: str = Field(default="bearer", description="令牌类型")
    user: UserResponse = Field(..., description="用户信息")


class TokenRefresh(BaseModel):
    """Token refresh request schema."""
    refresh_token: str = Field(..., description="刷新令牌")


class TokenPayload(BaseModel):
    """JWT token payload schema."""
    sub: str = Field(..., description="用户ID")
    username: str = Field(..., description="用户名")
    email: str = Field(..., description="邮箱")
    role: str = Field(..., description="角色")
    exp: datetime = Field(..., description="过期时间")
    iat: datetime = Field(..., description="签发时间")
    type: str = Field(..., description="令牌类型: access 或 refresh")