from pydantic import BaseModel, field_validator
from typing import Optional, Dict
from datetime import datetime

# EmailStr safely import karo
try:
    from pydantic import EmailStr
except ImportError:
    EmailStr = str  # fallback


class UserCreate(BaseModel):
    username: str
    email: EmailStr
    password: str

    @field_validator("username")
    @classmethod
    def username_alphanumeric(cls, v: str) -> str:
        if not v.replace("_", "").replace("-", "").isalnum():
            raise ValueError("Username must be alphanumeric (underscores/hyphens allowed)")
        if len(v) < 3:
            raise ValueError("Username must be at least 3 characters")
        return v

    @field_validator("password")
    @classmethod
    def password_strength(cls, v: str) -> str:
        if len(v) < 6:
            raise ValueError("Password must be at least 6 characters")
        return v


class UserOut(BaseModel):
    id: int
    username: str
    email: str
    created_at: datetime

    model_config = {"from_attributes": True}


class Token(BaseModel):
    access_token: str
    token_type: str = "bearer"
    user: UserOut


class LoginRequest(BaseModel):
    username: str
    password: str


class ProxyCreate(BaseModel):
    name: str
    openai_base_url: str
    openai_api_key: str
    model_mapping: Optional[Dict[str, str]] = {}


class ProxyUpdate(BaseModel):
    name: Optional[str] = None
    openai_base_url: Optional[str] = None
    openai_api_key: Optional[str] = None
    model_mapping: Optional[Dict[str, str]] = None


class ProxyOut(BaseModel):
    id: int
    name: str
    proxy_token: str
    openai_base_url: str
    model_mapping: str
    created_at: datetime

    model_config = {"from_attributes": True}