from datetime import datetime, timedelta
from typing import Optional
from fastapi import Depends, HTTPException, status, WebSocket
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from passlib.context import CryptContext
from sqlalchemy.orm import Session

from app.database import get_db
from app.models.user import User

# Настройки JWT
SECRET_KEY = "your-secret-key"  # В продакшене использовать безопасный ключ
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

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) -> str:
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        email: str = payload.get("sub")
        if email is None:
            raise credentials_exception
    except JWTError:
        raise credentials_exception
    
    user = db.query(User).filter(User.email == email).first()
    if user is None:
        raise credentials_exception
    return user

async def get_current_user_ws(websocket: WebSocket, db: Session = Depends(get_db)) -> Optional[User]:
    try:
        # Получаем токен из параметров запроса
        token = websocket.query_params.get("token")
        if not token:
            await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
            return None

        # Проверяем токен
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        email: str = payload.get("sub")
        if email is None:
            await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
            return None

        # Получаем пользователя
        user = db.query(User).filter(User.email == email).first()
        if user is None:
            await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
            return None

        return user

    except JWTError:
        await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
        return None