refactor: move provider env keys to GlobalConfig and optimize imports

Move PROVIDER_ENV_KEYS from app.py to GlobalConfig for better organization and maintainability. Also, optimize imports in llm_helper.py by removing unused imports and relocating the ChatOpenAI import to where it is needed.

app.py

@@ -26,24 +26,11 @@ import helpers.file_manager as filem
 from global_config import GlobalConfig
 from helpers import llm_helper, pptx_helper, text_helper
 
-
 load_dotenv()
 
-
 RUN_IN_OFFLINE_MODE = os.getenv('RUN_IN_OFFLINE_MODE', 'False').lower() == 'true'
 
-
-# --- API Key Environment Variable Mapping ---
-PROVIDER_ENV_KEYS = {
-    GlobalConfig.PROVIDER_OPENROUTER: "OPENROUTER_API_KEY",
-    GlobalConfig.PROVIDER_COHERE: "COHERE_API_KEY",
-    GlobalConfig.PROVIDER_HUGGING_FACE: "HUGGINGFACEHUB_API_TOKEN",
-    GlobalConfig.PROVIDER_GOOGLE_GEMINI: "GOOGLE_API_KEY",
-    GlobalConfig.PROVIDER_TOGETHER_AI: "TOGETHER_API_KEY",
-    GlobalConfig.PROVIDER_AZURE_OPENAI: "AZURE_OPENAI_API_KEY",
-    # Add more as needed
-}
-
+PROVIDER_REGEX = re.compile(r'\[(.*?)\]')
 
 @st.cache_data
 def _load_strings() -> dict:
@@ -196,9 +183,9 @@ with st.sidebar:
         ).split(' ')[0]
 
         # --- Automatically fetch API key from .env if available ---
-        provider_match = re.match(r'\[(.*?)\]', llm_provider_to_use)
+        provider_match = PROVIDER_REGEX.match(llm_provider_to_use)
         selected_provider = provider_match.group(1) if provider_match else llm_provider_to_use
-        env_key_name = PROVIDER_ENV_KEYS.get(selected_provider)
+        env_key_name = GlobalConfig.PROVIDER_ENV_KEYS.get(selected_provider)
         default_api_key = os.getenv(env_key_name, "") if env_key_name else ""
 
         # Always sync session state to env value if needed (auto-fill on provider change)
@@ -608,3 +595,4 @@ def main():
 
 if __name__ == '__main__':
     main()
+

global_config.py

@@ -20,10 +20,10 @@ class GlobalConfig:
     PROVIDER_COHERE = 'co'
     PROVIDER_GOOGLE_GEMINI = 'gg'
     PROVIDER_HUGGING_FACE = 'hf'
-    PROVIDER_OLLAMA = 'ol'
-    PROVIDER_TOGETHER_AI = 'to'
     PROVIDER_AZURE_OPENAI = 'az'
+    PROVIDER_OLLAMA = 'ol'
     PROVIDER_OPENROUTER = 'or'
+    PROVIDER_TOGETHER_AI = 'to'
     VALID_PROVIDERS = {
         PROVIDER_COHERE,
         PROVIDER_GOOGLE_GEMINI,
@@ -33,6 +33,14 @@ class GlobalConfig:
         PROVIDER_AZURE_OPENAI,
         PROVIDER_OPENROUTER,
     }
+    PROVIDER_ENV_KEYS = {
+        PROVIDER_COHERE: "COHERE_API_KEY",
+        PROVIDER_GOOGLE_GEMINI: "GOOGLE_API_KEY",
+        PROVIDER_HUGGING_FACE: "HUGGINGFACEHUB_API_TOKEN",
+        PROVIDER_AZURE_OPENAI: "AZURE_OPENAI_API_KEY",
+        PROVIDER_OPENROUTER: "OPENROUTER_API_KEY",
+        PROVIDER_TOGETHER_AI: "TOGETHER_API_KEY",
+    }
     VALID_MODELS = {
         '[az]azure/open-ai': {
             'description': 'faster, detailed',
@@ -64,6 +72,16 @@ class GlobalConfig:
             'max_new_tokens': 8192,
             'paid': False,
         },
+        '[or]google/gemini-2.0-flash-001': {
+            'description': 'Google Gemini-2.0-flash-001 (via OpenRouter)',
+            'max_new_tokens': 8192,
+            'paid': True,
+        },
+        '[or]openai/gpt-3.5-turbo': {
+            'description': 'OpenAI GPT-3.5 Turbo (via OpenRouter)',
+            'max_new_tokens': 4096,
+            'paid': True,
+        },
         '[to]meta-llama/Llama-3.3-70B-Instruct-Turbo': {
             'description': 'detailed, slower',
             'max_new_tokens': 4096,
@@ -73,15 +91,6 @@ class GlobalConfig:
             'description': 'shorter, faster',
             'max_new_tokens': 4096,
             'paid': True,
-        },
-        '[or]openai/gpt-3.5-turbo': {
-            'description': 'OpenAI GPT-3.5 Turbo (via OpenRouter)',
-            'max_new_tokens': 2048,
-        },
-        '[or]openrouter/gpt-4-omni': {
-            'description': 'OpenRouter GPT-4 Omni',
-            'max_new_tokens': 8192,
-            'paid': True,
         }
     }
     LLM_PROVIDER_HELP = (
@@ -90,8 +99,8 @@ class GlobalConfig:
         '- **[co]**: Cohere\n'
         '- **[gg]**: Google Gemini API\n'
         '- **[hf]**: Hugging Face Inference API\n'
-        '- **[to]**: Together AI\n'
         '- **[or]**: OpenRouter\n\n'
+        '- **[to]**: Together AI\n'
         '[Find out more](https://github.com/barun-saha/slide-deck-ai?tab=readme-ov-file#summary-of-the-llms)'
     )
     DEFAULT_MODEL_INDEX = int(os.environ.get('DEFAULT_MODEL_INDEX', '4'))

helpers/llm_helper.py

@@ -11,7 +11,6 @@ import requests
 from requests.adapters import HTTPAdapter
 from urllib3.util import Retry
 from langchain_core.language_models import BaseLLM, BaseChatModel
-from langchain_openai import ChatOpenAI
 import os
 
 sys.path.append('..')
@@ -191,10 +190,12 @@ def get_langchain_llm(
 
     if provider == GlobalConfig.PROVIDER_OPENROUTER:
         # Use langchain-openai's ChatOpenAI for OpenRouter
+        from langchain_openai import ChatOpenAI
+        
         logger.debug('Getting LLM via OpenRouter: %s', model)
-        openrouter_api_key = api_key or os.environ.get("OPENROUTER_API_KEY")
-        base_url = "https://openrouter.ai/api/v1"
-        # NOTE: model should be passed as model_name
+        openrouter_api_key = api_key
+        base_url = 'https://openrouter.ai/api/v1'
+       
         return ChatOpenAI(
             base_url=base_url,
             openai_api_key=openrouter_api_key,