package theme

import (
	"embed"
	"io/fs"
	"strings"

	dexweb "github.com/dexidp/dex/web"
)

const (
	Name     = "tug"
	Issuer   = "tug"
	themeDir = "themes/" + Name
)

//go:embed themes
var files embed.FS

type overlay struct {
	base fs.FS
	tug  fs.FS
}

func FS() fs.FS {
	return overlay{base: dexweb.FS(), tug: files}
}

func (o overlay) Open(name string) (fs.File, error) {
	if name == themeDir || strings.HasPrefix(name, themeDir+"/") {
		return o.tug.Open(name)
	}
	return o.base.Open(name)
}