#!/usr/bin/make -f

CODEPOINT := \\([0-9a-fA-F]{2,5})

.DELETE_ON_ERROR:
.SECONDARY:
.PHONY: all clean superclean

FORMATS := ttf woff
FONTSTANDARD := $(addprefix fontstandard.,$(FORMATS))

FAVERSION ?= v4.2.0
URL := https://github.com/FortAwesome/Font-Awesome/raw/$(FAVERSION)

SUBVERSION := 1
VERSION := $(shell echo $(FAVERSION) | sed -E 's/[^0-9]//g').$(SUBVERSION)
FONTAWESOME := FontAwesome_$(VERSION).otf
VARIABLES := variables_$(VERSION).less

all: $(FONTSTANDARD)

FONTFORGE ?= fontforge
CONVERT.ttf.woff := echo 'Open($$1); Generate($$2)' | $(FONTFORGE)

fontstandard.ttf: $(FONTAWESOME) fontstandard.fontforge
	$(FONTFORGE) $< $@ < fontstandard.fontforge

%.woff: %.ttf
	$(CONVERT.ttf.woff) $< $@

$(FONTAWESOME):
	wget -O $@ $(URL)/fonts/FontAwesome.otf

$(VARIABLES):
	wget -O $@ $(URL)/less/variables.less

%.fontforge: $(VARIABLES) %.remove.txt %.preamble.txt %.remap.txt
	echo 'Open($$1); Reencode("unicode4");' > $@
	sed -E 's/__VERSION__/$(VERSION)/' < $*.preamble.txt >> $@
	grep -E "@fa-var-("$$(grep -v '^#' $*.remove.txt \
		| paste -sd '|' -)")[-a-z]*:" $(VARIABLES) \
		| sed -E 's/.*$(CODEPOINT).*/SelectMore(0u\1);/g' >> $@
	echo 'DetachAndRemoveGlyphs();' >> $@

	grep -v '^#' $*.remap.txt | while read -r dst src rest; do \
		(grep -E -m 1 "@fa-var-$${src}:" $(VARIABLES) \
			|| echo "$${src} not found." >&2) \
		| sed -E 's/.*$(CODEPOINT).*/Select(0u\1); CopyReference(); Select(0u'$${dst}'); Paste();/g' >> $@ \
	; done

	echo 'Generate($$2)' >> $@

clean:
	$(RM) fontstandard.fontforge
	$(RM) $(FONTSTANDARD)

superclean: clean
	$(RM) $(FONTAWESOME)
	$(RM) $(VARIABLES)