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


class TokenBase(BaseModel):
    """Base token schema with common attributes."""
    token_type: str = Field(default="bearer", description="Type of authentication token")
    expires_in: int = Field(description="Token expiration time in seconds")


class Token(TokenBase):
    """Schema for authentication response containing both access and refresh tokens."""
    access_token: str = Field(description="JWT access token")
    refresh_token: str = Field(description="JWT refresh token for obtaining new access tokens")


class TokenPayload(BaseModel):
    """Schema representing the decoded JWT token payload."""
    sub: str = Field(description="Subject identifier (user ID)")
    type: str = Field(description="Token type (access or refresh)")
    exp: datetime = Field(description="Token expiration timestamp")
    iat: datetime = Field(description="Token issued at timestamp")
    jti: Optional[str] = Field(None, description="JWT ID - unique identifier for the token")


class RefreshToken(BaseModel):
    """Schema for refresh token requests."""
    refresh_token: str = Field(
        ...,
        description="JWT refresh token used to obtain new access tokens"
    )


class TokenResponse(BaseModel):
    """Schema for detailed token information response."""
    access_token: str = Field(description="JWT access token")
    refresh_token: str = Field(description="JWT refresh token")
    token_type: str = Field(default="bearer")
    expires_in: int = Field(description="Token expiration time in seconds")
    scope: Optional[str] = Field(None, description="Token scope")
    user_id: str = Field(description="ID of the authenticated user")

    class Config:
        json_schema_extra = {
            "example": {
                "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
                "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
                "token_type": "bearer",
                "expires_in": 1800,
                "scope": "read write",
                "user_id": "123e4567-e89b-12d3-a456-426614174000"
            }
        }