Add yfinance fallback for historical ratios when FMP quota is exhausted

FMP free tier caps at 250 req/day; hitting the limit caused the Historical
Ratios tab to show an error. get_historical_ratios_yfinance now computes
margins, ROE, ROA, D/E, P/E, P/B, P/S, and EV/EBITDA directly from
yfinance income statements, balance sheets, and price history. FMP
functions fall back to this automatically when they receive an empty
response.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 13 insertions, 5 deletions

diff --git a/services/fmp_service.py b/services/fmp_service.py
index bba6c85..3bfa5c1 100644
--- a/services/fmp_service.py
+++ b/services/fmp_service.py
@@ -3,7 +3,7 @@ import os
 import requests
 import streamlit as st
 from dotenv import load_dotenv
-from services.data_service import get_company_info
+from services.data_service import get_company_info, get_historical_ratios_yfinance
 
 load_dotenv()
 
@@ -121,16 +121,24 @@ def get_company_news(ticker: str, limit: int = 20) -> list[dict]:
 
 @st.cache_data(ttl=86400)
 def get_historical_ratios(ticker: str, limit: int = 10) -> list[dict]:
-    """Annual historical valuation ratios (P/E, P/B, P/S, EV/EBITDA, etc.)."""
+    """Annual historical valuation ratios (P/E, P/B, P/S, EV/EBITDA, etc.).
+    Falls back to yfinance-computed ratios if FMP returns empty (e.g. rate limit)."""
     data = _get(STABLE_BASE, "/ratios", params={"symbol": ticker.upper(), "limit": limit})
-    return data if isinstance(data, list) else []
+    if isinstance(data, list) and data:
+        return data
+    return get_historical_ratios_yfinance(ticker.upper())
 
 
 @st.cache_data(ttl=86400)
 def get_historical_key_metrics(ticker: str, limit: int = 10) -> list[dict]:
-    """Annual historical key metrics (ROE, ROA, margins, debt/equity, etc.)."""
+    """Annual historical key metrics (ROE, ROA, margins, debt/equity, etc.).
+    Falls back to yfinance-computed metrics if FMP returns empty (e.g. rate limit)."""
     data = _get(STABLE_BASE, "/key-metrics", params={"symbol": ticker.upper(), "limit": limit})
-    return data if isinstance(data, list) else []
+    if isinstance(data, list) and data:
+        return data
+    # yfinance fallback already covers all key metrics — return empty to avoid duplication
+    # (get_historical_ratios will have already provided the full merged dataset)
+    return []
 
 
 @st.cache_data(ttl=3600)