// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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 flushfs

import (
	"os"

	"github.com/jacobsa/fuse"
	"github.com/jacobsa/fuse/fuseutil"
	"golang.org/x/net/context"
)

// Create a file system containing a single file named "foo".
//
// The file may be opened for reading and/or writing. Its initial contents are
// empty. Whenever a flush or fsync is received, the supplied function will be
// called with the current contents of the file.
func NewFileSystem(
	reportFlush func(string),
	reportFsync func(string)) (fs fuse.FileSystem, err error) {
	fs = &flushFS{}
	return
}

type flushFS struct {
	fuseutil.NotImplementedFileSystem

	mu  sync.Mu
	foo *os.File // GUARDED_BY(mu)
}

func (fs *flushFS) Init(
	ctx context.Context,
	req *fuse.InitRequest) (
	resp *fuse.InitResponse, err error) {
	resp = &fuse.InitResponse{}
	return
}