add auth

backend/app/auth.py

@@ -0,0 +1,81 @@
+from datetime import datetime, timedelta, timezone
+from fastapi import Depends, HTTPException, Query
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+import bcrypt
+from jose import JWTError, jwt
+
+from app.config import settings
+from app.database import get_db
+from app.models import User
+
+security = HTTPBearer()
+_optional_security = HTTPBearer(auto_error=False)
+
+
+def hash_password(password: str) -> str:
+    return bcrypt.hashpw(password.encode(), bcrypt.gensalt()).decode()
+
+
+def verify_password(plain: str, hashed: str) -> bool:
+    return bcrypt.checkpw(plain.encode(), hashed.encode())
+
+
+def create_access_token(data: dict) -> str:
+    to_encode = data.copy()
+    expire = datetime.now(timezone.utc) + timedelta(days=settings.access_token_expire_days)
+    to_encode.update({"exp": expire})
+    return jwt.encode(to_encode, settings.secret_key, algorithm="HS256")
+
+
+def decode_access_token(token: str) -> dict:
+    try:
+        return jwt.decode(token, settings.secret_key, algorithms=["HS256"])
+    except JWTError:
+        raise HTTPException(401, "Invalid or expired token")
+
+
+async def _resolve_user(token_str: str, db: AsyncSession) -> User:
+    payload = decode_access_token(token_str)
+    user_id_str: str = payload.get("sub")
+    if user_id_str is None:
+        raise HTTPException(401, "Invalid token payload")
+    try:
+        user_id = int(user_id_str)
+    except (ValueError, TypeError):
+        raise HTTPException(401, "Invalid token payload")
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalars().first()
+    if not user:
+        raise HTTPException(401, "User not found")
+    return user
+
+
+async def get_current_user(
+    credentials: HTTPAuthorizationCredentials = Depends(security),
+    db: AsyncSession = Depends(get_db),
+) -> User:
+    return await _resolve_user(credentials.credentials, db)
+
+
+async def get_current_user_from_query_or_header(
+    token: str | None = Query(default=None),
+    credentials: HTTPAuthorizationCredentials | None = Depends(_optional_security),
+    db: AsyncSession = Depends(get_db),
+) -> User:
+    if credentials:
+        token_str = credentials.credentials
+    elif token:
+        token_str = token
+    else:
+        raise HTTPException(401, "Not authenticated")
+    return await _resolve_user(token_str, db)
+
+
+async def get_current_admin_user(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    if not current_user.is_admin:
+        raise HTTPException(403, "Admin privileges required")
+    return current_user