from datetime import datetime, timedelta, timezone
from typing import Optional
import os
from jose import JWTError, jwt
from passlib.context import CryptContext
from pydantic import BaseModel

# Secret JWT injecté par l'env (Vault -> .env). Repli dev uniquement ; en prod SECRET_KEY est obligatoire.
SECRET_KEY = os.getenv("SECRET_KEY", "dev-only-insecure-secret-change-me")
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = int(os.getenv("ACCESS_TOKEN_EXPIRE_MINUTES", "30"))

pwd_context = CryptContext(schemes=["argon2"], deprecated="auto")

class Token(BaseModel):
    access_token: str
    token_type: str

class TokenData(BaseModel):
    email: Optional[str] = None

class UserLogin(BaseModel):
    email: str
    password: str

class UserCreate(BaseModel):
    email: str
    password: str
    full_name: Optional[str] = None

class UserResponse(BaseModel):
    id: int
    email: str
    full_name: Optional[str] = None

def verify_password(plain_password: str, hashed_password: str) -> bool:
    return pwd_context.verify(plain_password, hashed_password)

def get_password_hash(password: str) -> str:
    return pwd_context.hash(password)

def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def decode_token(token: str) -> Optional[str]:
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        email: str = payload.get("sub")
        if email is None:
            return None
        return email
    except JWTError:
        return None