// Package webui embeds the compiled browser application in the Orchestra binary.
package webui

import (
	"embed"
	"io/fs"
	"net/http"
	"path"
	"strings"
)

//go:embed assets/* assets/assets/*
var files embed.FS

// Handler serves immutable fingerprinted assets and falls back to the SPA for
// browser routes. API routes are deliberately not handled here.
func Handler() http.Handler {
	root, _ := fs.Sub(files, "assets")
	static := http.FileServer(http.FS(root))
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		p := strings.TrimPrefix(path.Clean(r.URL.Path), "/")
		if p != "" && p != "." {
			if _, err := fs.Stat(root, p); err == nil {
				if strings.Contains(p, "/assets/") || strings.HasPrefix(p, "assets/") {
					w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
				}
				static.ServeHTTP(w, r)
				return
			}
		}
		w.Header().Set("Cache-Control", "no-cache")
		b, err := fs.ReadFile(root, "index.html")
		if err != nil { http.Error(w, "web UI unavailable", http.StatusInternalServerError); return }
		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		_, _ = w.Write(b)
	})
}