feat(api): Implement authentication router and secure dependencies

src/ea_chatbot/api/dependencies.py

@@ -0,0 +1,46 @@
+import os
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from ea_chatbot.config import Settings
+from ea_chatbot.history.manager import HistoryManager
+from ea_chatbot.auth import OIDCClient
+from ea_chatbot.api.utils import decode_access_token
+from ea_chatbot.history.models import User
+
+settings = Settings()
+
+# Shared instances
+history_manager = HistoryManager(settings.history_db_url)
+
+oidc_client = None
+if settings.oidc_client_id and settings.oidc_client_secret and settings.oidc_server_metadata_url:
+    oidc_client = OIDCClient(
+        client_id=settings.oidc_client_id,
+        client_secret=settings.oidc_client_secret,
+        server_metadata_url=settings.oidc_server_metadata_url,
+        redirect_uri=os.getenv("OIDC_REDIRECT_URI", "http://localhost:3000/auth/callback")
+    )
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/login")
+
+async def get_current_user(token: str = Depends(oauth2_scheme)) -> User:
+    """Dependency to get the current authenticated user from the JWT token."""
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Could not validate credentials",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+    
+    payload = decode_access_token(token)
+    if payload is None:
+        raise credentials_exception
+        
+    username: str | None = payload.get("sub")
+    if username is None:
+        raise credentials_exception
+        
+    user = history_manager.get_user(username)
+    if user is None:
+        raise credentials_exception
+        
+    return user

src/ea_chatbot/api/routers/auth.py

@@ -1,30 +1,13 @@
 from fastapi import APIRouter, Depends, HTTPException, status
-from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
+from fastapi.security import OAuth2PasswordRequestForm
 from pydantic import BaseModel, EmailStr
 from typing import Optional
-from ea_chatbot.config import Settings
-from ea_chatbot.history.manager import HistoryManager
-from ea_chatbot.auth import OIDCClient
 from ea_chatbot.api.utils import create_access_token
-
-settings = Settings()
-history_manager = HistoryManager(settings.history_db_url)
-
-# Initialize OIDC Client if configured
-oidc_client = None
-if settings.oidc_client_id and settings.oidc_client_secret and settings.oidc_server_metadata_url:
-    oidc_client = OIDCClient(
-        client_id=settings.oidc_client_id,
-        client_secret=settings.oidc_client_secret,
-        server_metadata_url=settings.oidc_server_metadata_url,
-        # This will be updated to the frontend URL later
-        redirect_uri="http://localhost:3000/auth/callback" 
-    )
+from ea_chatbot.api.dependencies import history_manager, oidc_client, get_current_user
+from ea_chatbot.history.models import User as UserDB
 
 router = APIRouter(prefix="/auth", tags=["auth"])
 
-oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/login")
-
 class Token(BaseModel):
     access_token: str
     token_type: str
@@ -79,7 +62,7 @@ async def oidc_login():
     """Get the OIDC authorization URL."""
     if not oidc_client:
         raise HTTPException(
-            status_code=status.HTTP_501_NOT_IMPLEMENTED,
+            status_code=status.HTTP_510_NOT_EXTENDED,
             detail="OIDC is not configured"
         )
     
@@ -87,12 +70,10 @@ async def oidc_login():
     return {"url": url}
 
 @router.get("/me", response_model=UserResponse)
-async def get_me(token: str = Depends(oauth2_scheme)):
+async def get_me(current_user: UserDB = Depends(get_current_user)):
     """Get the current authenticated user's profile."""
-    # This currently only validates the token exists via oauth2_scheme
-    # The next task will implement the full dependency to decode JWT and fetch user
     return {
-        "id": "unknown",
-        "email": "unknown",
-        "display_name": "unknown"
+        "id": str(current_user.id),
+        "email": current_user.username,
+        "display_name": current_user.display_name
     }

tests/api/test_auth.py

@@ -20,7 +20,7 @@ def mock_user():
 
 def test_register_user_success():
     """Test successful user registration."""
-    # We'll need to mock history_manager.get_user and create_user
+    # We mock it where it is used in the router
     with patch("ea_chatbot.api.routers.auth.history_manager") as mock_hm:
         mock_hm.get_user.return_value = None
         mock_hm.create_user.return_value = User(id="1", username="new@example.com", display_name="New")
@@ -30,7 +30,6 @@ def test_register_user_success():
             json={"email": "new@example.com", "password": "password123", "display_name": "New"}
         )
         
-        # This will fail now because the router doesn't exist
         assert response.status_code == 201
         assert response.json()["email"] == "new@example.com"
 
@@ -74,3 +73,20 @@ def test_oidc_login_redirect():
         response = client.get("/auth/oidc/login")
         assert response.status_code == 200
         assert response.json()["url"] == "https://oidc-provider.com/auth"
+
+def test_get_me_success():
+    """Test getting current user with a valid token."""
+    from ea_chatbot.api.utils import create_access_token
+    token = create_access_token(data={"sub": "test@example.com", "user_id": "123"})
+    
+    with patch("ea_chatbot.api.dependencies.history_manager") as mock_hm:
+        mock_hm.get_user.return_value = User(id="123", username="test@example.com", display_name="Test")
+        
+        response = client.get(
+            "/auth/me",
+            headers={"Authorization": f"Bearer {token}"}
+        )
+        
+        assert response.status_code == 200
+        assert response.json()["email"] == "test@example.com"
+        assert response.json()["id"] == "123"