sligro: Keep track of announced substitute products

inflatinator/revbank.py

@@ -5,7 +5,14 @@ import logging
 import scrapers
 import shlex
 
-profit_margin = Decimal('1.3')
+
+def resale_price(prod: scrapers.Product) -> Decimal:
+    profit_margin = Decimal('1.3')
+
+    # Apply profit margin and divide by the number of units per sold packaging.
+    unit_price = prod.price * profit_margin / prod.units
+    # Round up to 5ct.
+    return (unit_price * 20).quantize(Decimal('1'), rounding=ROUND_UP) / 20
 
 
 @dataclass
@@ -42,6 +49,15 @@ class Product:
             metadata=metadata,
         )
 
+    @staticmethod
+    def from_scraper(prod: scrapers.Product):
+        return Product(
+            aliases=[prod.gtin, *sorted(prod.aliases)],
+            price=resale_price(prod),
+            description=prod.name,
+            metadata={},
+        )
+
     def format_line(self):
         aliases = ','.join(self.aliases)
         price = f'{self.price:.2f}'
@@ -83,36 +99,60 @@ def update_product_pricings(src):
 
         try:
             prod_info = find_product_details(product)
+
         except NoAutoUpdate:
             logging.debug('no auto update: "%s"', product.description)
             lines_out.append(line)
             continue
+
         except scrapers.ProductNotFoundError:
-            logging.warn('not found "%s"', product.description)
             product.metadata['err'] = 'not_found'
+            # If this product was not found and has a substitute reference in its metadata, clear the scraping trigger.
+            if 'sub' in product.metadata and 'sligro' in product.metadata:
+                del product.metadata['sligro']
+                logging.info('"%s" is EOL', product.description)
+            else:
+                logging.warn('not found "%s"', product.description)
             lines_out.append(product.format_line())
             continue
+
         except Exception as err:
             logging.error('did not update "%s": %s', product.description, err)
             lines_out.append(line)
             continue
 
-        aliases = sorted(set(product.aliases) - {prod_info.gtin})
-        product.aliases = [prod_info.gtin, *aliases]
+        new_product = Product.from_scraper(prod_info)
 
-        # Apply profit margin and divide by the number of units per sold packaging.
-        unit_price = prod_info.price * profit_margin / prod_info.units
-        # Round up to 5ct.
+        product.description = new_product.description
+        logging.debug(f'Found "{new_product.description}", buy €{prod_info.price/prod_info.units:.2f}, sell €{new_product.price:.2f}')
+
+        # Merge any new aliases, keeping the gtin first.
+        product.aliases = [
+            prod_info.gtin,
+            *sorted((set(product.aliases) | set(new_product.aliases)) - {prod_info.gtin})
+        ]
+        # Adjust the price.
         previous_price = product.price
-        product.price = (unit_price * 20).quantize(Decimal('1'), rounding=ROUND_UP) / 20
-
+        product.price = new_product.price
+        if product.price != previous_price:
+            logging.info(f'Adjusted "{product.description}", €{previous_price:.2f} -> €{product.price:.2f}')
+        # If this product had an error set for any reason, clear it.
         if 'err' in product.metadata:
             del product.metadata['err']
 
+        # If this product is being substituted by another product, leave a reference.
+        # This will also help us determine whether the substitute has been rewritten already.
+        substitute_product = None
+        if prod_info.replacement is not None:
+            if 'sub' not in product.metadata:
+                substitute_product = Product.from_scraper(prod_info.replacement)
+                substitute_product.metadata['sligro'] = None
+            product.metadata['sub'] = prod_info.replacement.gtin
+
         lines_out.append(product.format_line())
 
-        logging.debug(f'Found "{prod_info.name}", buy €{prod_info.price/prod_info.units:.2f}, sell €{product.price:.2f}')
-        if product.price != previous_price:
-            logging.info(f'Adjusted "{prod_info.name}", €{previous_price:.2f} -> €{product.price:.2f}')
+        if substitute_product is not None:
+            lines_out.append(substitute_product.format_line())
+            logging.info(f'Found replacement of "{product.description}": {substitute_product.aliases[0]}')
 
     return '\n'.join(lines_out)