// Copyright 2019 Yunion
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package httputils

import (
	"net/http"
	"strings"
)

// http filesystem that prevent directory listing
// https://gist.github.com/hauxe/f2ea1901216177ccf9550a1b8bd59178#file-http_static_correct-go

// FileSystem custom file system handler
type FileSystem struct {
	fs http.FileSystem
}

// Open opens file
func (fs FileSystem) Open(path string) (http.File, error) {
	f, err := fs.fs.Open(path)
	if err != nil {
		return nil, err
	}

	s, err := f.Stat()
	if s.IsDir() {
		index := strings.TrimSuffix(path, "/") + "/index.html"
		if _, err := fs.fs.Open(index); err != nil {
			return nil, err
		}
	}

	return f, nil
}

func Dir(dir string) http.FileSystem {
	return FileSystem{
		http.Dir(dir),
	}
}