// Package labdb_static embeds labdb's HTML/CSS/JS into the binary so
// the fivenode_go process ships every byte the browser needs —
// no separate web server, no filesystem dependency.
//
// PRG surface
//
//	cBody := LABDB_STATIC_FILE(cPath)  -> file contents, or "" when missing
//	cMime := LABDB_STATIC_MIME(cPath)  -> Content-Type guessed from extension
//
// cPath is taken verbatim from hReq["path"], so "/" maps to index.html
// and a missing leading slash is fine.
package labdb_static

import (
	"embed"
	"path"
	"strings"

	"five/hbrt"
)

//go:embed public
var fs embed.FS

func init() {
	hbrt.HB_FUNC("LABDB_STATIC_FILE", staticFile)
	hbrt.HB_FUNC("LABDB_STATIC_MIME", staticMime)
}

// resolve turns "/" -> "public/index.html",
// "/css/app.css" -> "public/css/app.css",
// "css/app.css" -> "public/css/app.css".
func resolve(p string) string {
	p = strings.TrimPrefix(p, "/")
	if p == "" {
		p = "index.html"
	}
	// Normalize any "..", "//" so an attacker can't escape the embed root.
	cleaned := path.Clean("/" + p)
	if cleaned == "/" {
		return "public/index.html"
	}
	return "public" + cleaned
}

func staticFile(ctx *hbrt.HBContext) {
	if ctx.PCount() < 1 || !ctx.IsChar(1) {
		ctx.RetC("")
		return
	}
	data, err := fs.ReadFile(resolve(ctx.ParC(1)))
	if err != nil {
		ctx.RetC("")
		return
	}
	ctx.RetC(string(data))
}

func staticMime(ctx *hbrt.HBContext) {
	if ctx.PCount() < 1 || !ctx.IsChar(1) {
		ctx.RetC("application/octet-stream")
		return
	}
	// Use the resolved path so "/" -> .html, not "" -> octet-stream.
	ext := strings.ToLower(path.Ext(resolve(ctx.ParC(1))))
	switch ext {
	case ".html", ".htm":
		ctx.RetC("text/html; charset=utf-8")
	case ".css":
		ctx.RetC("text/css; charset=utf-8")
	case ".js", ".mjs":
		ctx.RetC("application/javascript; charset=utf-8")
	case ".json":
		ctx.RetC("application/json; charset=utf-8")
	case ".svg":
		ctx.RetC("image/svg+xml")
	case ".png":
		ctx.RetC("image/png")
	case ".jpg", ".jpeg":
		ctx.RetC("image/jpeg")
	case ".ico":
		ctx.RetC("image/x-icon")
	default:
		ctx.RetC("application/octet-stream")
	}
}