Refactor backend configuration and enhance news fetching functionality

- Introduced a Config dataclass in config.py to manage API keys, RSS feeds, and directory paths more effectively.
- Updated the NewsFetcher class to include retry logic for fetching articles from RSS feeds.
- Modified the EmbeddingGenerator and NewsRecommender classes to utilize the new configuration structure.
- Enhanced main.py to implement API token verification for secure access to news fetching and recommendations.

backend/config.py

@@ -1,5 +1,10 @@
+from dataclasses import dataclass, field
+from typing import List, Optional
 import os
 from dotenv import load_dotenv
+from fastapi import HTTPException, Depends, Security
+from fastapi.security import APIKeyHeader
+from starlette.status import HTTP_403_FORBIDDEN
 
 # Load environment variables
 
@@ -9,30 +14,59 @@ from dotenv import load_dotenv
 # Load environment variables from the specified path
 load_dotenv()
 
-# API Keys
-COHERE_API_KEY = os.getenv("COHERE_API_KEY")
-GROQ_API_KEY = os.getenv("GROQ_API_KEY")
-PINECONE_API_KEY = os.getenv("PINECONE_API_KEY")
+@dataclass
+class Config:
+    # API Keys
+    cohere_api_key: str = os.getenv("COHERE_API_KEY", "")
+    groq_api_key: str = os.getenv("GROQ_API_KEY", "")
+    pinecone_api_key: str = os.getenv("PINECONE_API_KEY", "")
+    api_token: str = os.getenv("API_TOKEN", "default_secret_token")  # Default token for development
 
-# Pinecone Configuration
-PINECONE_INDEX_NAME = os.getenv("PINECONE_INDEX_NAME", "news-articles")
+    # Pinecone Configuration
+    pinecone_index_name: str = os.getenv("PINECONE_INDEX_NAME", "news-articles")
+    vector_dimension: int = 1024  # Cohere embedding dimension
+    top_k_results: int = 5
 
-# News Sources
-RSS_FEEDS = [
-    # "https://feeds.feedburner.com/TechCrunch/",
-    # "https://www.theverge.com/rss/index.xml",
-    "https://www.wired.com/feed/rss",
-    "https://www.technologyreview.com/feed/",
-]
+    # News Sources
+    rss_feeds: List[str] = field(default_factory=lambda: [
+        # "https://feeds.feedburner.com/TechCrunch/",
+        # "https://www.theverge.com/rss/index.xml",
+        "https://www.wired.com/feed/rss",
+        "https://www.technologyreview.com/feed/",
+    ])
 
-# Vector Database Settings
-VECTOR_DIMENSION = 1024  # Cohere embedding dimension
-TOP_K_RESULTS = 5
+    # Data Directories
+    raw_news_dir: str = "data/raw_news"
+    processed_news_dir: str = "data/processed_news"
 
-# Data Directories
-RAW_NEWS_DIR = "data/raw_news"
-PROCESSED_NEWS_DIR = "data/processed_news"
+    def __post_init__(self):
+        # Create directories if they don't exist
+        os.makedirs(self.raw_news_dir, exist_ok=True)
+        os.makedirs(self.processed_news_dir, exist_ok=True)
 
-# Create directories if they don't exist
-os.makedirs(RAW_NEWS_DIR, exist_ok=True)
-os.makedirs(PROCESSED_NEWS_DIR, exist_ok=True)
+# Create a global config instance
+config = Config()
+
+# API Key header
+api_key_header = APIKeyHeader(name="X-API-Token", auto_error=False)
+
+def verify_api_token(api_key: str):
+    """
+    Verify the API token from the request header.
+    
+    Args:
+        api_key: The API key from the request header
+        
+    Returns:
+        The API key if valid
+        
+    Raises:
+        HTTPException: If the API key is invalid
+    """
+    if api_key == config.api_token:
+        print(f"API key verified: {api_key}")
+        return api_key
+    raise HTTPException(
+        status_code=HTTP_403_FORBIDDEN, 
+        detail="Invalid API token"
+    )