package static

import (
	"net/http"
	"os"
)

// Dir serves the files in the given directory or
// uses the given HandlerFunc to handles missing files
func Dir(dirPath string, stripPrefix string, notFound http.HandlerFunc) http.HandlerFunc {

	root := http.Dir(dirPath)
	fs := http.FileServer(root)

	fn := func(w http.ResponseWriter, r *http.Request) {
		if _, err := os.Stat(dirPath + r.RequestURI); os.IsNotExist(err) {
			notFound.ServeHTTP(w, r)
		} else {
			fs.ServeHTTP(w, r)
		}
	}

	handler := http.StripPrefix(stripPrefix, http.HandlerFunc(fn))

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		handler.ServeHTTP(w, r)
	})
}