Add authentication routes and tests for API

Implemented comprehensive authentication endpoints including user registration, login, token refresh, password change, and user info retrieval. Added extensive test cases for these endpoints to ensure functionality and error handling.

backend/app/api/routes/auth.py

@@ -1,3 +1,231 @@
-from fastapi import APIRouter
+# app/api/routes/auth.py
+import logging
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, status, Body
+from fastapi.security import OAuth2PasswordRequestForm
+from sqlalchemy.orm import Session
+
+from app.api.dependencies.auth import get_current_user
+from app.core.auth import TokenExpiredError, TokenInvalidError
+from app.core.database import get_db
+from app.models.user import User
+from app.schemas.users import (
+    UserCreate,
+    UserResponse,
+    Token,
+    LoginRequest,
+    RefreshTokenRequest
+)
+from app.services.auth_service import AuthService, AuthenticationError
 
 router = APIRouter()
+logger = logging.getLogger(__name__)
+
+
+@router.post("/register", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
+async def register_user(
+        user_data: UserCreate,
+        db: Session = Depends(get_db)
+) -> Any:
+    """
+    Register a new user.
+    
+    Returns:
+        The created user information.
+    """
+    try:
+        user = AuthService.create_user(db, user_data)
+        return user
+    except AuthenticationError as e:
+        logger.warning(f"Registration failed: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail=str(e)
+        )
+    except Exception as e:
+        logger.error(f"Unexpected error during registration: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An unexpected error occurred. Please try again later."
+        )
+
+
+@router.post("/login", response_model=Token)
+async def login(
+        login_data: LoginRequest,
+        db: Session = Depends(get_db)
+) -> Any:
+    """
+    Login with username and password.
+    
+    Returns:
+        Access and refresh tokens.
+    """
+    try:
+        # Attempt to authenticate the user
+        user = AuthService.authenticate_user(db, login_data.email, login_data.password)
+
+        # Explicitly check for None result and raise correct exception
+        if user is None:
+            logger.warning(f"Invalid login attempt for: {login_data.email}")
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Invalid email or password",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+
+        # User is authenticated, generate tokens
+        tokens = AuthService.create_tokens(user)
+        logger.info(f"User login successful: {user.email}")
+        return tokens
+
+    except HTTPException:
+        # Re-raise HTTP exceptions without modification
+        raise
+    except AuthenticationError as e:
+        # Handle specific authentication errors like inactive accounts
+        logger.warning(f"Authentication failed: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail=str(e),
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    except Exception as e:
+        # Handle unexpected errors
+        logger.error(f"Unexpected error during login: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An unexpected error occurred. Please try again later."
+        )
+
+
+@router.post("/login/oauth", response_model=Token)
+async def login_oauth(
+        form_data: OAuth2PasswordRequestForm = Depends(),
+        db: Session = Depends(get_db)
+) -> Any:
+    """
+    OAuth2-compatible login endpoint, used by the OpenAPI UI.
+    
+    Returns:
+        Access and refresh tokens.
+    """
+    try:
+        user = AuthService.authenticate_user(db, form_data.username, form_data.password)
+
+        if user is None:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Invalid email or password",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+
+        # Generate tokens
+        tokens = AuthService.create_tokens(user)
+
+        # Format response for OAuth compatibility
+        return {
+            "access_token": tokens.access_token,
+            "refresh_token": tokens.refresh_token,
+            "token_type": tokens.token_type
+        }
+    except HTTPException:
+        raise
+    except AuthenticationError as e:
+        logger.warning(f"OAuth authentication failed: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail=str(e),
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    except Exception as e:
+        logger.error(f"Unexpected error during OAuth login: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An unexpected error occurred. Please try again later."
+        )
+
+
+@router.post("/refresh", response_model=Token)
+async def refresh_token(
+        refresh_data: RefreshTokenRequest,
+        db: Session = Depends(get_db)
+) -> Any:
+    """
+    Refresh access token using a refresh token.
+    
+    Returns:
+        New access and refresh tokens.
+    """
+    try:
+        tokens = AuthService.refresh_tokens(db, refresh_data.refresh_token)
+        return tokens
+    except TokenExpiredError:
+        logger.warning("Token refresh failed: Token expired")
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Refresh token has expired. Please log in again.",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    except TokenInvalidError:
+        logger.warning("Token refresh failed: Invalid token")
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid refresh token",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    except Exception as e:
+        logger.error(f"Unexpected error during token refresh: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An unexpected error occurred. Please try again later."
+        )
+
+
+@router.post("/change-password", status_code=status.HTTP_200_OK)
+async def change_password(
+        current_password: str = Body(..., embed=True),
+        new_password: str = Body(..., embed=True),
+        current_user: User = Depends(get_current_user),
+        db: Session = Depends(get_db)
+) -> Any:
+    """
+    Change current user's password.
+    
+    Requires authentication.
+    """
+    try:
+        success = AuthService.change_password(
+            db=db,
+            user_id=current_user.id,
+            current_password=current_password,
+            new_password=new_password
+        )
+
+        if success:
+            return {"message": "Password changed successfully"}
+    except AuthenticationError as e:
+        logger.warning(f"Password change failed: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=str(e)
+        )
+    except Exception as e:
+        logger.error(f"Unexpected error during password change: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An unexpected error occurred. Please try again later."
+        )
+
+
+@router.get("/me", response_model=UserResponse)
+async def get_current_user_info(
+        current_user: User = Depends(get_current_user)
+) -> Any:
+    """
+    Get current user information.
+    
+    Requires authentication.
+    """
+    return current_user