Improve AOAI authentication code (remove duplicate code, add comments…

…, move API version to constant) (#11)

Remove key and add comments, move API version to constant

app/utils/llm.py

@@ -10,6 +10,8 @@
 from openai.types import CompletionUsage
 from utils.identity import get_token_provider
 
+AZURE_OPENAI_API_VERSION = "2024-09-01-preview"
+
 PROMPT = """
 Create a highly engaging podcast script between two people based on the input text. Use informal language to enhance the human-like quality of the conversation, including expressions like \"wow,\" laughter, and pauses such as \"uhm.\"
 
@@ -104,16 +106,17 @@ def document_to_podcast_script(
 ) -> PodcastScriptResponse:
     """Get LLM response."""
 
+    # Authenticate via API key (not advised for production)
     if os.getenv("AZURE_OPENAI_KEY"):
         client = AzureOpenAI(
             api_key=os.getenv("AZURE_OPENAI_KEY"),
-            api_version="2024-09-01-preview",
+            api_version=AZURE_OPENAI_API_VERSION,
             azure_endpoint=os.getenv("AZURE_OPENAI_ENDPOINT"),
         )
+    # Authenticate via DefaultAzureCredential (e.g. managed identity or Azure CLI)
     else:
         client = AzureOpenAI(
-            api_key=os.getenv("AZURE_OPENAI_KEY"),
-            api_version="2024-09-01-preview",
+            api_version=AZURE_OPENAI_API_VERSION,
             azure_ad_token_provider=get_token_provider(),
         )