added combined discount for consumer so codes can be calculated on the fly for any monitor

src/monitor_utils/runner.py

@@ -116,6 +116,27 @@ async def setup_config(
     return category_names, config["channels"], collection
 
 
+def combined_discount(base_percentage: int, promo_percentage: int | None) -> int:
+    """Combine an on-sale discount with a percentage code applied at checkout.
+
+    A "extra N% off" code discounts the already-reduced sale price, so the two
+    compound rather than add: 20% off then an extra 30% code is 44% off list,
+    not 50%. Returns base_percentage unchanged when there is no percentage code.
+
+    Args:
+        base_percentage: The on-sale discount off list, as a whole percent.
+        promo_percentage: The code's advertised percent off, or None.
+
+    Returns:
+        The combined discount off list, rounded to a whole percent.
+    """
+
+    if not promo_percentage:
+        return base_percentage
+
+    return round(100 - (100 - base_percentage) * (100 - promo_percentage) / 100)
+
+
 def build_product_details(
     product: dict,
     min_percentage: int,
@@ -148,7 +169,11 @@ def build_product_details(
 
     percentage = int(((original_price - current_price) / original_price) * 100)
     price_drop = original_price - current_price
-    passes_percentage = percentage >= min_percentage
+    # A percentage code compounds onto the sale price, so an item can clear the
+    # threshold on the combined discount even when the base discount would not.
+    # Dollar codes do not map to a percent and never affect the threshold.
+    effective_percentage = combined_discount(percentage, product.get("promoPercentage"))
+    passes_percentage = effective_percentage >= min_percentage
     passes_price_drop = min_price_drop is not None and price_drop >= min_price_drop
     if not passes_percentage and not passes_price_drop:
         return
@@ -164,6 +189,10 @@ def build_product_details(
             overstock_text=product["overstockText"],
             percentage=percentage,
             affiliate_url=product.get("affiliateUrl"),
+            promo_code=product.get("promoCode"),
+            promo_percentage=product.get("promoPercentage"),
+            promo_dollar_off=product.get("promoDollarOff"),
+            promo_min_spend=product.get("promoMinSpend"),
         ),
         timing=ProductTiming(
             discovered_date=product["discoveredDate"],
@@ -351,7 +380,7 @@ async def execute_pagination(
 
     async def fetch_page(page_index: int):
         """Fetch a single page or offset, optionally under the shared semaphore."""
-        async with (semaphore or nullcontext()):
+        async with semaphore or nullcontext():
             if stop_event.is_set():
                 return