import [add-common-feature add-feature add-lookup BeginLookupBlock EndLookupBlock] from "./table-util"

# Name-driven feature pairs
export : define [buildPairFeature sink tag1 tag2 glyphStore codedOnly] : begin
	local rec : BeginLookupBlock sink

	local mapTag2 {.}
	local mapTag1 {.}
	define reHidden : regex "^\\."
	define reTag1 : new RegExp ("\\." + tag1 + "$")
	foreach { glyphName glyph } [glyphStore.namedEntries] : begin
		if ([reTag1.test glyphName] && ![reHidden.test glyphName]) : do
			local gnTag2    : glyphName.replace reTag1 ('.' + tag2)
			local glyphTag2 : glyphStore.queryByName gnTag2
			if (glyphTag2) : begin
				if(!codedOnly || [glyphStore.queryUnicodeOf glyph])
					set mapTag2.(glyphName) gnTag2
				if(!codedOnly || [glyphStore.queryUnicodeOf glyphTag2])
					set mapTag1.(gnTag2) glyphName

	if [objectIsNotEmpty mapTag1] : begin
		define lookup1 : add-lookup sink {.type 'gsub_single' .substitutions mapTag1}
		define feature1 : add-feature sink tag1
		feature1.lookups.push lookup1
		add-common-feature sink feature1

	if [objectIsNotEmpty mapTag2] : begin
		define lookup2 : add-lookup sink {.type 'gsub_single' .substitutions mapTag2}
		define feature2 : add-feature sink tag2
		feature2.lookups.push lookup2
		add-common-feature sink feature2

	EndLookupBlock rec sink

define [objectIsNotEmpty obj] : obj && [Object.keys obj].length