// Copyright 2024 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 find_input_delta_lib

import (
	"io/fs"
	"os"
)

// OsFs provides a minimal implementation so that we can use testing/fstest for
// unit tests.
var OsFs fileSystem = osFS{}

type fileSystem interface {
	Open(path string) (fs.File, error)
	Stat(path string) (os.FileInfo, error)
	ReadFile(path string) ([]byte, error)
}

// osFS implements fileSystem using the local disk.
type osFS struct{}

func (osFS) Open(path string) (fs.File, error)     { return os.Open(path) }
func (osFS) Stat(path string) (os.FileInfo, error) { return os.Stat(path) }
func (osFS) ReadFile(path string) ([]byte, error)  { return os.ReadFile(path) }