Add backend foundation: database models, security, and mail processing service

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

backend/app/core/deps.py

@@ -0,0 +1,133 @@
+"""
+Authentication dependencies for FastAPI.
+"""
+from typing import Optional
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer, HTTPBearer, HTTPAuthorizationCredentials
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select
+
+from app.core.database import get_db
+from app.core.security import decode_token
+from app.models.database_models import User
+
+# OAuth2 scheme for token authentication
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl=f"/api/v1/auth/login", auto_error=False)
+http_bearer = HTTPBearer(auto_error=False)
+
+
+async def get_current_user(
+    token: Optional[str] = Depends(oauth2_scheme),
+    credentials: Optional[HTTPAuthorizationCredentials] = Depends(http_bearer),
+    db: AsyncSession = Depends(get_db)
+) -> User:
+    """
+    Get current authenticated user from JWT token.
+    Supports both OAuth2 password bearer and HTTP Bearer authentication.
+    """
+    # Get token from either source
+    auth_token = token or (credentials.credentials if credentials else None)
+    
+    if not auth_token:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Not authenticated",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    
+    # Decode token
+    payload = decode_token(auth_token)
+    if not payload:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid authentication credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    
+    # Verify token type
+    token_type = payload.get("type")
+    if token_type != "access":
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid token type",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    
+    # Get user ID from token
+    user_id: Optional[int] = payload.get("sub")
+    if user_id is None:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid token payload",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    
+    # Fetch user from database
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    
+    if user is None:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="User not found",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="User account is inactive"
+        )
+    
+    return user
+
+
+async def get_current_active_user(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    """Get current active user"""
+    if not current_user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Inactive user"
+        )
+    return current_user
+
+
+async def get_current_superuser(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    """Get current superuser"""
+    if not current_user.is_superuser:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions"
+        )
+    return current_user
+
+
+def check_subscription_tier(required_tier: str):
+    """
+    Dependency factory to check if user has required subscription tier.
+    Returns a dependency function.
+    """
+    tier_hierarchy = {
+        "free": 0,
+        "basic": 1,
+        "pro": 2,
+        "enterprise": 3
+    }
+    
+    async def check_tier(current_user: User = Depends(get_current_active_user)) -> User:
+        user_tier_level = tier_hierarchy.get(current_user.subscription_tier.value, 0)
+        required_tier_level = tier_hierarchy.get(required_tier, 0)
+        
+        if user_tier_level < required_tier_level:
+            raise HTTPException(
+                status_code=status.HTTP_402_PAYMENT_REQUIRED,
+                detail=f"This feature requires {required_tier} subscription or higher"
+            )
+        
+        return current_user
+    
+    return check_tier