package api

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

// docsFS holds the Swagger UI page and its vendored swagger-ui-dist 5.17.14
// assets, so /docs works on a network with no internet access (huma's own
// renderers load their JavaScript from a CDN).
//
//go:embed docsui
var docsFS embed.FS

// registerDocs serves Swagger UI at /docs and its assets under /docs/assets/.
func registerDocs(mux *http.ServeMux) {
	sub, err := fs.Sub(docsFS, "docsui")
	if err != nil {
		panic("api: embedded docs missing: " + err.Error()) // the embed directive guarantees the directory
	}
	page, err := fs.ReadFile(sub, "index.html")
	if err != nil {
		panic("api: embedded docs page missing: " + err.Error())
	}
	mux.HandleFunc("GET /docs", func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		_, _ = w.Write(page)
	})
	mux.Handle("GET /docs/assets/", http.StripPrefix("/docs/assets/", http.FileServerFS(sub)))
}