auth.py

import os
import re
from dotenv import load_dotenv
from fastapi import HTTPException, Depends
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from sqlalchemy.orm import Session
from datetime import datetime, timedelta, timezone
from database import get_db
from models import User
from passlib.context import CryptContext

load_dotenv()

# 비밀번호 해싱을 위한 CryptContext 객체 생성
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

# 비밀번호 해싱 함수
def hash_password(password: str) -> str:
    return pwd_context.hash(password)

def is_valid_email(email: str) -> bool:
    email_regex = r'^[a-zA-Z0-9_.+-]+@[a-zAZ0-9-]+\.[a-zA-Z0-9-.]+$'
    return re.match(email_regex, email) is not None

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

SECRET_KEY = os.getenv("SECRET_KEY", "default_key")
ALGORITHM = os.getenv("ALGORITHM", "HS256")
ACCESS_TOKEN_EXPIRE_MINUTES = int(os.getenv("ACCESS_TOKEN_EXPIRE_MINUTES", 60))

# JWT 생성 함수
def create_access_token(data: dict, expires_delta: timedelta = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)):
    to_encode = data.copy()
    expire = datetime.utcnow() + expires_delta
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="users/login")  # 토큰을 가져올 경로

# JWT 토큰 검증 함수
def verify_token(token: str):
    credentials_exception = HTTPException(
        status_code=401,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        exp_timestamp = payload.get("exp")
        print("Decoded payload:", payload)
        if exp_timestamp:
            exp_datetime = datetime.fromtimestamp(exp_timestamp, tz=timezone.utc)
            if datetime.now(timezone.utc) > exp_datetime:
                raise credentials_exception  # 만료된 토큰일 경우
        return payload  # payload는 토큰에서 디코딩된 사용자 정보
    except JWTError:
        raise credentials_exception

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)) -> dict:
    payload = verify_token(token)  # verify_token은 토큰을 검증하고 payload를 반환
    user_email = payload.get("sub")  # "sub"는 이메일에 해당할 수 있음 (다른 방식으로 설정했으면 그에 맞게 변경)

    # 이메일을 통해 사용자를 찾음
    user = db.query(User).filter(User.email == user_email).first()
    if not user:
        raise HTTPException(status_code=401, detail="User not found")
    
    return {"userId": user.userId, "email": user.email, "nickname": user.nickname}