// Copyright 2019 Amazon.com, Inc. or its affiliates. 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. A copy of the
// License is located at
//
//	http://aws.amazon.com/apache2.0/
//
// or in the "license" file accompanying this file. This file 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 volumes

import (
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestSaveStateSuccess(t *testing.T) {
	s := NewStateManager()
	s.VolState.Volumes["vol"] = &VolumeInfo{
		Type: "efs",
		Path: "/vol",
	}
	saveStateToDisk = func(b []byte) error {
		assert.Equal(t, string(`{
	"volumes": {
		"vol": {
			"type": "efs",
			"path": "/vol"
		}
	}
}`), string(b))
		return nil
	}
	defer func() {
		saveStateToDisk = saveState
	}()
	assert.NoError(t, s.save())
}

func TestSaveStateToDisk(t *testing.T) {
	s := NewStateManager()
	s.VolState.Volumes["vol"] = &VolumeInfo{
		Type: "efs",
		Path: "/vol",
	}
	saveStateToDisk = func(b []byte) error {
		return nil
	}
	defer func() {
		saveStateToDisk = saveState
	}()
	assert.NoError(t, s.save())
}

func TestSaveStateToDiskFail(t *testing.T) {
	s := NewStateManager()
	s.VolState.Volumes["vol"] = &VolumeInfo{
		Type: "efs",
		Path: "/vol",
	}
	saveStateToDisk = func(b []byte) error {
		return errors.New("write to disk failure")
	}
	defer func() {
		saveStateToDisk = saveState
	}()
	assert.Error(t, s.save())
}

func TestLoadStateSuccess(t *testing.T) {
	s := NewStateManager()
	oldState := &VolumeState{}
	readStateFile = func() ([]byte, error) {
		return []byte(`{"volumes":{"efsVolume":{"type":"efs","options":{"device":"fs-123","o":"tls","type":"efs"}}}}`), nil
	}
	defer func() {
		readStateFile = readFile
	}()
	assert.NoError(t, s.load(oldState))
}

// Tests backwards compatibility of state loading.
// A change to state format has been introduced with reference counting of volume mounts.
func TestLoadStateFromOldFormat(t *testing.T) {
	s := NewStateManager()
	oldState := &VolumeState{}
	readStateFile = func() ([]byte, error) {
		return []byte(`
        {
            "volumes": {
                "efsVolume": {
                    "type":"efs",
                    "mounts": {"id1": null}
                }
            }
        }`), nil
	}
	defer func() {
		readStateFile = readFile
	}()
	require.NoError(t, s.load(oldState))
	assert.Equal(t,
		&VolumeState{Volumes: map[string]*VolumeInfo{"efsVolume": {
			Type:   "efs",
			Mounts: map[string]int{"id1": 0},
		}}},
		oldState)
}

func TestLoadInvalidState(t *testing.T) {
	s := NewStateManager()
	oldState := &VolumeState{}
	readStateFile = func() ([]byte, error) {
		return []byte(`"junk"`), nil
	}
	defer func() {
		readStateFile = readFile
	}()
	assert.Error(t, s.load(oldState))
}
