// Package tokencheck is the shared half of every component's
// "...UseDefinedTokens" test: each var(--rst-*) a component stylesheet
// reads must be defined by the pinned rastrillo's tokens.css plus
// estilo's theme. AGENTS.md's two-pin case, for components.
package tokencheck

import (
	"regexp"

	"amadan.net/oficina/estilo.git/theme"
	"github.com/carlosframework/rastrillo/ui"
)

var (
	definition = regexp.MustCompile(`(--rst-[a-z0-9-]+)\s*:`)
	reference  = regexp.MustCompile(`var\(\s*(--rst-[a-z0-9-]+)`)
)

// Undefined returns the rastrillo tokens css reads that neither
// ui.TokensCSS() nor theme.CSS() defines, and how many references it
// read in total, so a caller can refuse a stylesheet that reads none
// (a check over nothing passes vacuously).
func Undefined(css []byte) (missing []string, references int) {
	defined := map[string]bool{}
	for _, m := range definition.FindAllSubmatch(append(append([]byte{}, ui.TokensCSS()...), theme.CSS()...), -1) {
		defined[string(m[1])] = true
	}
	for _, m := range reference.FindAllSubmatch(css, -1) {
		references++
		if !defined[string(m[1])] {
			missing = append(missing, string(m[1]))
		}
	}
	return missing, references
}