package router

import (
	"embed"
	"html/template"
	"io/fs"
	"net/http"
	"os"
	"path/filepath"
	"runtime"
	"strings"

	"go.jolheiser.com/overlay"
)

var (
	//go:embed templates
	templateFS embed.FS
	ofs        = overlay.MustNew(customRoot(), templateFS)
	Version    string
)

func customRoot() string {
	bin, err := os.Executable()
	if err != nil {
		bin = ""
	}
	customPath := os.Getenv("VANITY_CUSTOM")
	if customPath == "" {
		customPath = filepath.Join(bin, "custom")
	}
	return customPath
}

func tmpl(domain, name string) (*template.Template, error) {
	return template.New(name).Funcs(funcMap(domain)).ParseFS(ofs, "templates/base.tmpl", "templates/"+name)
}

func static() http.Handler {
	sub, err := fs.Sub(ofs, "templates/static")
	if err != nil {
		return nil
	}
	return http.FileServer(http.FS(sub))
}

func funcMap(domain string) template.FuncMap {
	return template.FuncMap{
		"AppVer": func() string {
			return Version
		},
		"GoVer": func() string {
			return runtime.Version()
		},
		"Domain": func() string {
			return strings.TrimSuffix(domain, "/")
		},
	}
}