feat: Allow a percent_max to be specified in ingredients Fixes #5369 (#…

…7639)

* Allow a percent_max to be specified in ingredients

* Update lib/ProductOpener/Ingredients.pm

Co-authored-by: Stéphane Gigandet <stephane@openfoodfacts.org>

* Additional guard against maximum. Note test doesn't fail without this

* Make else block consistent

* Set MSYS_NO_PATHCONV for Windows and added update_tests_results make task

* Limiting scope so can't contradict stated percentages

* Catch empty ingredients and removed debugging

* Fix perltidty

* Fix for perlcritic

* Cope with multiple constrained ingredients

Co-authored-by: Stéphane Gigandet <stephane@openfoodfacts.org>

Makefile

@@ -11,7 +11,7 @@ UID ?= $(shell id -u)
 export USER_UID:=${UID}
 
 export CPU_COUNT=$(shell nproc || echo 1)
-
+export MSYS_NO_PATHCONV=1
 
 DOCKER_COMPOSE=docker-compose --env-file=${ENV_FILE}
 # we run tests in a specific project name to be separated from dev instances
@@ -224,6 +224,10 @@ test-int: guard-test # usage: make test-one test=test-file.t
 stop_tests:
 	${DOCKER_COMPOSE_TEST} stop
 
+update_tests_results:
+	@echo "🥫 Updated expected test results with actuals for easy Git diff"
+	${DOCKER_COMPOSE_TEST} run --rm -w /opt/product-opener/tests backend bash update_tests_results.sh
+
 # check perl compiles, (pattern rule) / but only for newer files
 %.pm %.pl: _FORCE
 	if [ -f $@ ]; then perl -c -CS -Ilib $@; else true; fi

lib/ProductOpener/Ingredients.pm

@@ -2468,6 +2468,10 @@ Otherwise use 0 for percent_min and total_max for percent_max.
 =cut
 
 sub init_percent_values ($total_min, $total_max, $ingredients_ref) {
+	# Set maximum percentages if defined in the taxonomy (only do this for top-level ingredients)
+	if ($total_max == 100) {
+		set_percent_max_from_taxonomy($ingredients_ref);
+	}
 
 	# Determine if percent listed are absolute (default) or relative to a parent ingredient
 
@@ -2542,6 +2546,66 @@ sub init_percent_values ($total_min, $total_max, $ingredients_ref) {
 	return;
 }
 
+=head2 set_percent_max_from_taxonomy ( ingredients_ref )
+
+Set the percentage maximum for ingredients like flavouring where this is defined
+on the Ingredients taxonomy. The percent_max will not be applied in the following cases:
+
+ - if applying the percent_max would mean that it is not possible for the ingredient
+   total to add up to 100%
+ - If a later ingredient has a higher percentage than the percent_max of the restricted ingredient
+
+=cut
+
+sub set_percent_max_from_taxonomy ($ingredients_ref) {
+	# Exit if the first ingredient is constrained
+	if (!@{$ingredients_ref}
+		|| defined get_inherited_property("ingredients", $ingredients_ref->[0]{id}, "percent_max:en"))
+	{
+		return;
+	}
+
+	# Loop backwards through ingredients, checking that we don't set a percent_max that
+	# would be lower than the defined percentage of any ingredient that comes afterwards
+	my $highest_later_percent = 0;
+	for (my $index = scalar @{$ingredients_ref} - 1; $index > 0; $index--) {
+		my $ingredient = $ingredients_ref->[$index];
+		my $current_percent = $ingredient->{percent};
+		if (defined $current_percent) {
+			if ($current_percent > $highest_later_percent) {
+				$highest_later_percent = $current_percent;
+			}
+		}
+		else {
+			# See if taxonomy defines a maximum percent
+			my $percent_max = get_inherited_property("ingredients", $ingredient->{id}, "percent_max:en");
+			if (defined $percent_max and $percent_max >= $highest_later_percent) {
+				# Maximum percantage for ingredients like flavourings
+				$ingredient->{percent_max} = $percent_max;
+			}
+		}
+	}
+
+	# Loop forwards through the ingredients to make sure that the maximum
+	# does not limit preceding ingredients where percent is specified
+	my $remaining_percent = 100;
+	for my $ingredient (@{$ingredients_ref}) {
+		my $defined_percent = $ingredient->{percent};
+		if (!defined $defined_percent) {
+			my $percent_max = $ingredient->{percent_max};
+			if (defined $percent_max && $percent_max < $remaining_percent) {
+				delete $ingredient->{percent_max};
+			}
+			last;
+		}
+		else {
+			$remaining_percent = $remaining_percent - $defined_percent;
+		}
+	}
+
+	return;
+}
+
 sub set_percent_max_values ($total_min, $total_max, $ingredients_ref) {
 
 	my $changed = 0;