package web

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

//go:embed dist/*
var distFS embed.FS

// GetFileSystem returns an http.FileSystem for the embedded web UI files
func GetFileSystem() http.FileSystem {
	subFS, err := fs.Sub(distFS, "dist")
	if err != nil {
		panic(err)
	}
	return http.FS(subFS)
}

// SPAHandler returns an http.Handler that serves the embedded SPA
// It serves static files if they exist, otherwise falls back to index.html
func SPAHandler() http.Handler {
	fsys := GetFileSystem()
	fileServer := http.FileServer(fsys)

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		path := r.URL.Path

		// Try to open the file
		f, err := fsys.Open(strings.TrimPrefix(path, "/"))
		if err != nil {
			// File doesn't exist, serve index.html for SPA routing
			r.URL.Path = "/"
			fileServer.ServeHTTP(w, r)
			return
		}
		f.Close()

		// File exists, serve it
		fileServer.ServeHTTP(w, r)
	})
}