always-make = $(filter -B,$(MAKEFLAGS))

cssprojectinfiles = $(foreach file,$(if $1,$(shell find $1 -name '*.scss')),$(if $(filter-out _%,$(notdir $(file))),$(file)))
cssprojectoutfiles = $(patsubst %.scss,%.css,$(call cssprojectinfiles,$1))

$(cssprojects):
	sass --update --stop-on-error$(if $(beautify), --style expanded)$(if $(finalize),, --debug-info)$(if $(always-make), --force) $@
	$(if $(beautify),perl -i -pe 's/  /\t/g' $(call cssprojectoutfiles,$@))

clean::
	rm -f $(call cssprojectoutfiles,$(cssprojects))
	rm -rf .sass-cache

.PHONY: clean $(cssprojects)