package api

import (
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

// newStaticHandler serves the Astro static build with SPA fallbacks:
// /search/<id> and /tools/<name> → their respective shell pages.
func newStaticHandler(dir string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		urlPath := r.URL.Path

		if strings.HasPrefix(urlPath, "/search/") && len(urlPath) > len("/search/") {
			http.ServeFile(w, r, filepath.Join(dir, "search", "_", "index.html"))
			return
		}

		if strings.HasPrefix(urlPath, "/tools/") {
			rest := strings.TrimPrefix(urlPath, "/tools/")
			if rest != "" && !strings.Contains(rest, "/") {
				http.ServeFile(w, r, filepath.Join(dir, "tools", "_", "index.html"))
				return
			}
		}

		rel := filepath.FromSlash(strings.TrimPrefix(urlPath, "/"))
		full := filepath.Join(dir, rel)

		info, err := os.Stat(full)
		if err == nil && info.IsDir() {
			full = filepath.Join(full, "index.html")
			if _, err2 := os.Stat(full); err2 != nil {
				serve404(w, r, dir)
				return
			}
		} else if err != nil {
			serve404(w, r, dir)
			return
		}

		http.ServeFile(w, r, full)
	})
}

func serve404(w http.ResponseWriter, r *http.Request, dir string) {
	p := filepath.Join(dir, "404.html")
	if _, err := os.Stat(p); err == nil {
		w.WriteHeader(http.StatusNotFound)
		http.ServeFile(w, r, p)
		return
	}
	http.NotFound(w, r)
}