seaweedfs/weed/filer/filer_lazy_remote_test.go

package filer

import (
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"sort"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/seaweedfs/seaweedfs/weed/cluster"
	"github.com/seaweedfs/seaweedfs/weed/pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/remote_pb"
	"github.com/seaweedfs/seaweedfs/weed/remote_storage"
	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
	"github.com/seaweedfs/seaweedfs/weed/util"
	"github.com/seaweedfs/seaweedfs/weed/util/log_buffer"
	"github.com/seaweedfs/seaweedfs/weed/wdclient"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/protobuf/proto"
)

// --- minimal FilerStore stub ---

type stubFilerStore struct {
	mu              sync.Mutex
	entries         map[string]*Entry
	kv              map[string][]byte
	insertErr       error
	findErr         error
	findErrByPath   map[string]error
	kvPutErr        error
	kvGetErr        error
	kvDeleteErr     error
	kvGetHook       func(key []byte)
	deleteErrByPath map[string]error
}

func newStubFilerStore() *stubFilerStore {
	return &stubFilerStore{
		entries:         make(map[string]*Entry),
		kv:              make(map[string][]byte),
		deleteErrByPath: make(map[string]error),
	}
}

func (s *stubFilerStore) setKvPutErr(err error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.kvPutErr = err
}

func (s *stubFilerStore) GetName() string                             { return "stub" }
func (s *stubFilerStore) Initialize(util.Configuration, string) error { return nil }
func (s *stubFilerStore) Shutdown()                                   {}
func (s *stubFilerStore) BeginTransaction(ctx context.Context) (context.Context, error) {
	return ctx, nil
}
func (s *stubFilerStore) CommitTransaction(context.Context) error   { return nil }
func (s *stubFilerStore) RollbackTransaction(context.Context) error { return nil }
func (s *stubFilerStore) KvPut(_ context.Context, key []byte, value []byte) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.kvPutErr != nil {
		return s.kvPutErr
	}
	s.kv[string(key)] = append([]byte(nil), value...)
	return nil
}
func (s *stubFilerStore) KvGet(_ context.Context, key []byte) ([]byte, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.kvGetHook != nil {
		s.kvGetHook(key)
	}
	if s.kvGetErr != nil {
		return nil, s.kvGetErr
	}
	value, found := s.kv[string(key)]
	if !found {
		return nil, ErrKvNotFound
	}
	return append([]byte(nil), value...), nil
}
func (s *stubFilerStore) KvDelete(_ context.Context, key []byte) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.kvDeleteErr != nil {
		return s.kvDeleteErr
	}
	delete(s.kv, string(key))
	return nil
}
func (s *stubFilerStore) DeleteFolderChildren(_ context.Context, dirPath util.FullPath) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	prefix := string(dirPath) + "/"
	for k := range s.entries {
		if strings.HasPrefix(k, prefix) {
			delete(s.entries, k)
		}
	}
	return nil
}
func (s *stubFilerStore) listDirectoryChildNames(dirPath util.FullPath, startFileName string, includeStartFile bool, namePrefix string) []string {
	s.mu.Lock()
	defer s.mu.Unlock()
	dirPrefix := string(dirPath) + "/"
	var names []string
	for k := range s.entries {
		if !strings.HasPrefix(k, dirPrefix) {
			continue
		}
		rest := k[len(dirPrefix):]
		if strings.Contains(rest, "/") {
			continue
		}
		if namePrefix != "" && !strings.HasPrefix(rest, namePrefix) {
			continue
		}
		if rest > startFileName || (includeStartFile && rest == startFileName) {
			names = append(names, rest)
		}
	}
	sort.Strings(names)
	return names
}
func (s *stubFilerStore) getEntry(path string) *Entry {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.entries[path]
}
func (s *stubFilerStore) ListDirectoryEntries(_ context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc ListEachEntryFunc) (string, error) {
	names := s.listDirectoryChildNames(dirPath, startFileName, includeStartFile, "")
	dirPrefix := string(dirPath) + "/"
	lastFileName := ""
	for i, name := range names {
		if int64(i) >= limit {
			break
		}
		entry := s.getEntry(dirPrefix + name)
		cont, err := eachEntryFunc(entry)
		if err != nil {
			return lastFileName, err
		}
		lastFileName = name
		if !cont {
			break
		}
	}
	return lastFileName, nil
}
func (s *stubFilerStore) ListDirectoryPrefixedEntries(_ context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc ListEachEntryFunc) (string, error) {
	names := s.listDirectoryChildNames(dirPath, startFileName, includeStartFile, prefix)
	dirPrefix := string(dirPath) + "/"
	lastFileName := ""
	for i, name := range names {
		if int64(i) >= limit {
			break
		}
		entry := s.getEntry(dirPrefix + name)
		cont, err := eachEntryFunc(entry)
		if err != nil {
			return lastFileName, err
		}
		lastFileName = name
		if !cont {
			break
		}
	}
	return lastFileName, nil
}

func (s *stubFilerStore) InsertEntry(_ context.Context, entry *Entry) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.insertErr != nil {
		return s.insertErr
	}
	s.entries[string(entry.FullPath)] = entry
	return nil
}

func (s *stubFilerStore) UpdateEntry(_ context.Context, entry *Entry) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.entries[string(entry.FullPath)] = entry
	return nil
}

func (s *stubFilerStore) FindEntry(_ context.Context, p util.FullPath) (*Entry, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.findErr != nil {
		return nil, s.findErr
	}
	if err := s.findErrByPath[string(p)]; err != nil {
		return nil, err
	}
	if e, ok := s.entries[string(p)]; ok {
		return e, nil
	}
	return nil, filer_pb.ErrNotFound
}

func (s *stubFilerStore) DeleteEntry(_ context.Context, p util.FullPath) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if deleteErr, found := s.deleteErrByPath[string(p)]; found && deleteErr != nil {
		return deleteErr
	}
	delete(s.entries, string(p))
	return nil
}

// --- minimal RemoteStorageClient stub ---

type stubRemoteClient struct {
	statResult *filer_pb.RemoteEntry
	statErr    error
	deleteErr  error
	removeErr  error

	deleteCalls []*remote_pb.RemoteStorageLocation
	removeCalls []*remote_pb.RemoteStorageLocation

	listDirFn    func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error
	listDirCalls int
}

func (c *stubRemoteClient) StatFile(*remote_pb.RemoteStorageLocation) (*filer_pb.RemoteEntry, error) {
	return c.statResult, c.statErr
}
func (c *stubRemoteClient) Traverse(*remote_pb.RemoteStorageLocation, remote_storage.VisitFunc) error {
	return nil
}
func (c *stubRemoteClient) ReadFile(*remote_pb.RemoteStorageLocation, int64, int64) ([]byte, error) {
	return nil, nil
}
func (c *stubRemoteClient) WriteDirectory(*remote_pb.RemoteStorageLocation, *filer_pb.Entry) error {
	return nil
}
func (c *stubRemoteClient) RemoveDirectory(loc *remote_pb.RemoteStorageLocation) error {
	c.removeCalls = append(c.removeCalls, &remote_pb.RemoteStorageLocation{
		Name:   loc.Name,
		Bucket: loc.Bucket,
		Path:   loc.Path,
	})
	return c.removeErr
}
func (c *stubRemoteClient) WriteFile(*remote_pb.RemoteStorageLocation, *filer_pb.Entry, io.Reader) (*filer_pb.RemoteEntry, error) {
	return nil, nil
}
func (c *stubRemoteClient) UpdateFileMetadata(*remote_pb.RemoteStorageLocation, *filer_pb.Entry, *filer_pb.Entry) (*filer_pb.RemoteEntry, error) {
	return nil, nil
}
func (c *stubRemoteClient) DeleteFile(loc *remote_pb.RemoteStorageLocation) error {
	c.deleteCalls = append(c.deleteCalls, &remote_pb.RemoteStorageLocation{
		Name:   loc.Name,
		Bucket: loc.Bucket,
		Path:   loc.Path,
	})
	return c.deleteErr
}
func (c *stubRemoteClient) ListDirectory(_ context.Context, loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
	c.listDirCalls++
	if c.listDirFn != nil {
		return c.listDirFn(loc, visitFn)
	}
	return nil
}
func (c *stubRemoteClient) ListBuckets() ([]*remote_storage.Bucket, error) { return nil, nil }
func (c *stubRemoteClient) CreateBucket(string) error                      { return nil }
func (c *stubRemoteClient) DeleteBucket(string) error                      { return nil }

// stubConditionalRemoteClient adds the optional conditional-delete interface:
// callers binding stat and delete into one preconditioned request never reach
// StatFile or DeleteFile.
type stubConditionalRemoteClient struct {
	stubRemoteClient
	conditionalResult bool
	conditionalErr    error
	conditionalCalls  []*remote_pb.RemoteStorageLocation
}

func (c *stubConditionalRemoteClient) DeleteFileIfUnchanged(loc *remote_pb.RemoteStorageLocation, _ *filer_pb.RemoteEntry) (bool, error) {
	c.conditionalCalls = append(c.conditionalCalls, loc)
	return c.conditionalResult, c.conditionalErr
}

// --- stub RemoteStorageClientMaker ---

type stubClientMaker struct {
	client remote_storage.RemoteStorageClient
}

func (m *stubClientMaker) Make(*remote_pb.RemoteConf) (remote_storage.RemoteStorageClient, error) {
	return m.client, nil
}
func (m *stubClientMaker) HasBucket() bool { return true }

// --- test filer factory ---

func newTestFiler(t *testing.T, store *stubFilerStore, rs *FilerRemoteStorage) *Filer {
	t.Helper()
	dialOption := grpc.WithTransportCredentials(insecure.NewCredentials())
	mc := wdclient.NewMasterClient(
		dialOption, "test", cluster.FilerType,
		pb.ServerAddress("localhost:0"), "", "",
		*pb.NewServiceDiscoveryFromMap(map[string]pb.ServerAddress{}),
	)
	f := &Filer{
		RemoteStorage:       rs,
		Store:               NewFilerStoreWrapper(store),
		FilerConf:           NewFilerConf(),
		MaxFilenameLength:   255,
		MasterClient:        mc,
		FileIdDeletionQueue: util.NewUnboundedQueue(),
		deletionQuit:        make(chan struct{}),
		remoteTombstones:    newRemoteDeletionTombstones(),
		LocalMetaLogBuffer: log_buffer.NewLogBuffer("test", time.Minute,
			func(*log_buffer.LogBuffer, time.Time, time.Time, []byte, int64, int64) {}, nil, func() {}),
	}
	// A live LogBuffer keeps its flush loops and their multi-buffer pool
	// reachable; without this the package's filers pin gigabytes on 32-bit.
	t.Cleanup(func() {
		f.LocalMetaLogBuffer.ShutdownLogBuffer()
		f.LocalMetaLogBuffer.WaitForShutdown()
	})
	return f
}

// registerStubMaker registers a stub RemoteStorageClientMaker for the given
// type string and returns a cleanup function that restores the previous maker.
func registerStubMaker(t *testing.T, storageType string, client remote_storage.RemoteStorageClient) func() {
	t.Helper()
	prev := remote_storage.RemoteStorageClientMakers[storageType]
	remote_storage.RemoteStorageClientMakers[storageType] = &stubClientMaker{client: client}
	return func() {
		if prev != nil {
			remote_storage.RemoteStorageClientMakers[storageType] = prev
		} else {
			delete(remote_storage.RemoteStorageClientMakers, storageType)
		}
	}
}

// putConfigEntry stores a filer entry whose content is a serialized configuration.
func putConfigEntry(store *stubFilerStore, path string, content []byte) {
	store.entries[path] = &Entry{
		FullPath: util.FullPath(path),
		Attr: Attr{
			Mtime:  time.Unix(1700000000, 0),
			Crtime: time.Unix(1700000000, 0),
			Mode:   0644,
		},
		Content: content,
	}
}

// putDirEntry stores a plain directory entry, so a lazy fetch below it finds its parent in place.
func putDirEntry(store *stubFilerStore, path string) {
	store.entries[path] = &Entry{FullPath: util.FullPath(path), Attr: Attr{Mode: os.ModeDir | 0755}}
}

// --- tests ---

func TestMaybeLazyFetchFromRemote_HitsRemoteAndPersists(t *testing.T) {
	const storageType = "stub_lazy_hit"
	stub := &stubRemoteClient{
		statResult: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 1234, RemoteContentEncoding: proto.String("zstd")},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "mystore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "mystore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	entry, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/file.txt")
	require.NoError(t, err)
	require.NotNil(t, entry)
	assert.Equal(t, util.FullPath("/buckets/mybucket/file.txt"), entry.FullPath)
	assert.Equal(t, int64(1234), entry.Remote.RemoteSize)
	assert.Equal(t, uint64(1234), entry.FileSize)

	// entry must have been persisted in the store
	stored, sErr := store.FindEntry(context.Background(), "/buckets/mybucket/file.txt")
	require.NoError(t, sErr)
	assert.Equal(t, int64(1234), stored.Remote.RemoteSize)
	assert.Equal(t, []byte("zstd"), stored.Extended["Content-Encoding"])
}

// pathStatRemoteClient stats only the objects it holds, keyed by remote path.
type pathStatRemoteClient struct {
	stubRemoteClient
	objects   map[string]*filer_pb.RemoteEntry
	statCalls []string
}

func (c *pathStatRemoteClient) StatFile(loc *remote_pb.RemoteStorageLocation) (*filer_pb.RemoteEntry, error) {
	c.statCalls = append(c.statCalls, loc.Path)
	if remoteEntry, found := c.objects[loc.Path]; found {
		return remoteEntry, nil
	}
	return nil, remote_storage.ErrRemoteObjectNotFound
}

func newPathStatFiler(t *testing.T, storageType string, client remote_storage.RemoteStorageClient) (*Filer, *stubFilerStore) {
	t.Helper()
	t.Cleanup(registerStubMaker(t, storageType, client))
	conf := &remote_pb.RemoteConf{Name: "mystore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "mystore",
		Bucket: "mybucket",
		Path:   "/",
	})
	store := newStubFilerStore()
	return newTestFiler(t, store, rs), store
}

func TestMaybeLazyFetchFromRemote_PersistsParentDirectories(t *testing.T) {
	stub := &pathStatRemoteClient{objects: map[string]*filer_pb.RemoteEntry{
		"/a/b/file.bin":  {RemoteMtime: 1700000000, RemoteSize: 1234},
		"/a/b/other.bin": {RemoteMtime: 1700000000, RemoteSize: 5678},
	}}
	f, store := newPathStatFiler(t, "stub_lazy_parents", stub)

	const filePath = "/buckets/mybucket/a/b/file.bin"
	entry, err := f.maybeLazyFetchFromRemote(context.Background(), filePath)
	require.NoError(t, err)
	require.NotNil(t, entry)
	assert.Equal(t, []string{"/a/b/file.bin", "/a", "/a/b"}, stub.statCalls, "each missing parent is stat'ed once")

	for _, dir := range []string{"/buckets/mybucket/a", "/buckets/mybucket/a/b"} {
		dirEntry := store.getEntry(dir)
		require.NotNil(t, dirEntry, "parent %s not persisted", dir)
		assert.True(t, dirEntry.IsDirectory(), "%s should be a directory", dir)
		assert.Nil(t, dirEntry.Remote, "%s holds no remote object", dir)
	}

	// A sibling finds its parents in place and stats only itself.
	stub.statCalls = nil
	_, err = f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/a/b/other.bin")
	require.NoError(t, err)
	assert.Equal(t, []string{"/a/b/other.bin"}, stub.statCalls)

	// Once the content is cached, eviction walks down from the mount and must reach it.
	stored := store.getEntry(filePath)
	require.NotNil(t, stored)
	stored.Chunks = []*filer_pb.FileChunk{{FileId: "1,01637037d6", Size: 1234}}
	stored.Remote.LastLocalSyncTsNs = time.Now().UnixNano()
	require.NoError(t, store.UpdateEntry(context.Background(), stored))

	evictable := f.ListEvictableRemoteEntries(context.Background(), []util.FullPath{"/buckets/mybucket"}, 0)
	require.Len(t, evictable, 1)
	assert.Equal(t, util.FullPath(filePath), evictable[0].FullPath)
}

func TestMaybeLazyFetchFromRemote_ParentLookupStopsAtStoreError(t *testing.T) {
	stub := &pathStatRemoteClient{objects: map[string]*filer_pb.RemoteEntry{
		"/a/b/file.bin": {RemoteMtime: 1700000000, RemoteSize: 1234},
	}}
	f, store := newPathStatFiler(t, "stub_lazy_parent_store_error", stub)
	store.findErrByPath = map[string]error{"/buckets/mybucket/a/b": errors.New("store unavailable")}

	_, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/a/b/file.bin")
	require.NoError(t, err)
	assert.Equal(t, []string{"/a/b/file.bin"}, stub.statCalls, "a parent the store cannot read is not treated as missing")
}

func TestMaybeLazyFetchFromRemote_PromotesRemoteObjectAtParentKey(t *testing.T) {
	stub := &pathStatRemoteClient{objects: map[string]*filer_pb.RemoteEntry{
		"/reports":          {RemoteMtime: 1700000000, RemoteSize: 10},
		"/reports/2026.csv": {RemoteMtime: 1700000000, RemoteSize: 20},
	}}
	f, store := newPathStatFiler(t, "stub_lazy_prefix_object", stub)

	_, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/reports/2026.csv")
	require.NoError(t, err)

	parent := store.getEntry("/buckets/mybucket/reports")
	require.NotNil(t, parent)
	assert.True(t, parent.IsDirectory())
	assert.Equal(t, []byte("true"), parent.Extended[s3_constants.SeaweedFSPrefixObject], "the remote object at the parent key must stay readable")
	require.NotNil(t, parent.Remote)
	assert.Equal(t, int64(10), parent.Remote.RemoteSize)
}

func TestMaybeLazyFetchFromRemote_StatsEachParentOnce(t *testing.T) {
	stub := &pathStatRemoteClient{objects: map[string]*filer_pb.RemoteEntry{
		"/a/b/c/file.bin": {RemoteMtime: 1700000000, RemoteSize: 1234},
	}}
	f, _ := newPathStatFiler(t, "stub_lazy_parent_stats", stub)

	_, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/a/b/c/file.bin")
	require.NoError(t, err)
	assert.Equal(t, []string{"/a/b/c/file.bin", "/a", "/a/b", "/a/b/c"}, stub.statCalls,
		"a parent still missing after its own stat must not be re-stat'ed by the next lookup")
}

func TestMaybeLazyListFromRemote_PersistsParentDirectories(t *testing.T) {
	stub := &pathStatRemoteClient{objects: map[string]*filer_pb.RemoteEntry{}}
	stub.listDirFn = func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
		return visitFn("/", "file.bin", false, &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 1234})
	}
	f, store := newPathStatFiler(t, "stub_lazy_list_parents", stub)
	f.RemoteStorage.mapDirectoryToRemoteStorage("/buckets/listmount", &remote_pb.RemoteStorageLocation{
		Name:                   "mystore",
		Bucket:                 "listmount",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/listmount/a/b"))

	assert.Equal(t, []string{"/a"}, stub.statCalls, "each missing parent is stat'ed once")
	for _, dir := range []string{"/buckets/listmount", "/buckets/listmount/a", "/buckets/listmount/a/b"} {
		dirEntry := store.getEntry(dir)
		require.NotNil(t, dirEntry, "%s not persisted", dir)
		assert.True(t, dirEntry.IsDirectory(), "%s should be a directory", dir)
	}

	child := store.getEntry("/buckets/listmount/a/b/file.bin")
	require.NotNil(t, child)
	child.Chunks = []*filer_pb.FileChunk{{FileId: "1,01637037d6", Size: 1234}}
	child.Remote.LastLocalSyncTsNs = time.Now().UnixNano()
	require.NoError(t, store.UpdateEntry(context.Background(), child))

	evictable := f.ListEvictableRemoteEntries(context.Background(), []util.FullPath{"/buckets/listmount"}, 0)
	require.Len(t, evictable, 1)
	assert.Equal(t, util.FullPath("/buckets/listmount/a/b/file.bin"), evictable[0].FullPath)
}

func TestDeleteEntryMetaAndData_EmptyFolderUnderMountKeepsRemotePrefix(t *testing.T) {
	stub := &pathStatRemoteClient{objects: map[string]*filer_pb.RemoteEntry{
		"/dir/unread.bin": {RemoteMtime: 1700000000, RemoteSize: 1},
	}}
	f, store := newPathStatFiler(t, "stub_lazy_empty_folder", stub)
	dirPath := util.FullPath("/buckets/mybucket/dir")
	putDirEntry(store, string(dirPath))

	require.NoError(t, f.DeleteEntryMetaAndData(context.Background(), dirPath, false, false, false, false, nil, time.Time{}))

	assert.Empty(t, stub.removeCalls, "an empty local folder must not remove its remote prefix")
	assert.Nil(t, store.getEntry(string(dirPath)))
	entry, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/dir/unread.bin")
	require.NoError(t, err)
	assert.NotNil(t, entry, "a metadata-only delete must not block lazy reads under the folder")
}

func TestDeleteEmptyParentDirectories_UnderMountKeepsRemotePrefix(t *testing.T) {
	stub := &pathStatRemoteClient{}
	f, store := newPathStatFiler(t, "stub_lazy_expired_parents", stub)
	f.DirBucketsPath = "/buckets"
	putDirEntry(store, "/buckets/mybucket/a")
	putDirEntry(store, "/buckets/mybucket/a/b")

	f.DeleteEmptyParentDirectories(context.Background(), "/buckets/mybucket/a/b", "/buckets")

	assert.Empty(t, stub.removeCalls, "an empty local folder must not remove its remote prefix")
	assert.Nil(t, store.getEntry("/buckets/mybucket/a/b"))
	assert.Nil(t, store.getEntry("/buckets/mybucket/a"))
}

func TestIsUnderRemoteMount(t *testing.T) {
	rs := NewFilerRemoteStorage()
	rs.mapDirectoryToRemoteStorage("/buckets/mirror", &remote_pb.RemoteStorageLocation{
		Name:   "mystore",
		Bucket: "mirror",
		Path:   "/",
	})
	f := newTestFiler(t, newStubFilerStore(), rs)

	for path, want := range map[util.FullPath]bool{
		"/buckets/mirror":     true,
		"/buckets/mirror/a/b": true,
		"/buckets/mirror2/a":  false,
		"/buckets/local/a":    false,
	} {
		assert.Equal(t, want, f.IsUnderRemoteMount(path), path)
	}
}

func TestMaybeLazyFetchFromRemote_NotUnderMount(t *testing.T) {
	rs := NewFilerRemoteStorage()
	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	entry, err := f.maybeLazyFetchFromRemote(context.Background(), "/not/a/mounted/path.txt")
	require.NoError(t, err)
	assert.Nil(t, entry)
}

func TestMaybeLazyFetchFromRemote_RemoteObjectNotFound(t *testing.T) {
	const storageType = "stub_lazy_notfound"
	stub := &stubRemoteClient{statErr: remote_storage.ErrRemoteObjectNotFound}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "storenotfound", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "storenotfound",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	entry, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/missing.txt")
	require.NoError(t, err)
	assert.Nil(t, entry)
}

func TestMaybeLazyFetchFromRemote_CreateEntryFailureReturnsInMemoryEntry(t *testing.T) {
	const storageType = "stub_lazy_saveerr"
	stub := &stubRemoteClient{
		statResult: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 42},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "storesaveerr", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "storesaveerr",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	store.insertErr = errors.New("simulated store failure")
	f := newTestFiler(t, store, rs)

	// even with a store failure, the in-memory entry should be returned
	entry, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/failfile.txt")
	require.NoError(t, err)
	require.NotNil(t, entry, "should return in-memory entry even when CreateEntry fails")
	assert.Equal(t, int64(42), entry.Remote.RemoteSize)
}

func TestMaybeLazyFetchFromRemote_LongestPrefixMount(t *testing.T) {
	// Register maker for the root mount
	const typeRoot = "stub_lp_root"
	stubRoot := &stubRemoteClient{statResult: &filer_pb.RemoteEntry{RemoteMtime: 1, RemoteSize: 10}}
	defer registerStubMaker(t, typeRoot, stubRoot)()

	// Register maker for the prefix mount
	const typePrefix = "stub_lp_prefix"
	stubPrefix := &stubRemoteClient{statResult: &filer_pb.RemoteEntry{RemoteMtime: 2, RemoteSize: 20}}
	defer registerStubMaker(t, typePrefix, stubPrefix)()

	rs := NewFilerRemoteStorage()
	rs.storageNameToConf["rootstore"] = &remote_pb.RemoteConf{Name: "rootstore", Type: typeRoot}
	rs.storageNameToConf["prefixstore"] = &remote_pb.RemoteConf{Name: "prefixstore", Type: typePrefix}

	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name: "rootstore", Bucket: "root-bucket", Path: "/",
	})
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket/prefix", &remote_pb.RemoteStorageLocation{
		Name: "prefixstore", Bucket: "prefix-bucket", Path: "/",
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	// path under root mount only
	entryRoot, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/file.txt")
	require.NoError(t, err)
	require.NotNil(t, entryRoot)
	assert.Equal(t, int64(10), entryRoot.Remote.RemoteSize, "root mount should be used")

	// path under nested (longer) mount — must prefer the longer prefix
	entryPrefix, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/prefix/file.txt")
	require.NoError(t, err)
	require.NotNil(t, entryPrefix)
	assert.Equal(t, int64(20), entryPrefix.Remote.RemoteSize, "nested mount should win (longest prefix)")
}

type countingRemoteClient struct {
	stubRemoteClient
	statCalls int
}

func (c *countingRemoteClient) StatFile(loc *remote_pb.RemoteStorageLocation) (*filer_pb.RemoteEntry, error) {
	c.statCalls++
	return c.stubRemoteClient.StatFile(loc)
}

func TestMaybeLazyFetchFromRemote_ContextGuardPreventsRecursion(t *testing.T) {
	const storageType = "stub_lazy_guard"
	countingStub := &countingRemoteClient{
		stubRemoteClient: stubRemoteClient{
			statResult: &filer_pb.RemoteEntry{RemoteMtime: 1, RemoteSize: 1},
		},
	}
	defer registerStubMaker(t, storageType, countingStub)()

	conf := &remote_pb.RemoteConf{Name: "guardstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "guardstore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	guardCtx := context.WithValue(context.Background(), lazyFetchContextKey{}, true)
	entry, err := f.maybeLazyFetchFromRemote(guardCtx, "/buckets/mybucket/file.txt")
	require.NoError(t, err)
	assert.Nil(t, entry)
	assert.Equal(t, 0, countingStub.statCalls, "guard should prevent StatFile from being called")
}

func TestCreateEntry_SkipsTheLazyFetchInsideAStoreTransaction(t *testing.T) {
	const storageType = "stub_lazy_tx"
	countingStub := &countingRemoteClient{
		stubRemoteClient: stubRemoteClient{
			statResult: &filer_pb.RemoteEntry{RemoteMtime: 1, RemoteSize: 1},
		},
	}
	f, store := newMountedTestFiler(t, storageType, countingStub, 0)
	putDirEntry(store, "/buckets/mybucket/dir")
	// the stub opens no transaction of its own; the filer marks it anyway
	txCtx, err := f.BeginTransaction(context.Background())
	require.NoError(t, err)

	// a create inside the transaction: its lookup does not consult the
	// remote, the entry is inserted as given
	created := &Entry{FullPath: "/buckets/mybucket/dir/a.txt", Attr: Attr{Mode: 0644, Mtime: time.Now(), Crtime: time.Now()}}
	require.NoError(t, f.CreateEntry(txCtx, created, nil, false, false, nil, false, f.MaxFilenameLength))
	assert.Equal(t, 0, countingStub.statCalls, "a create inside a transaction must not consult the remote")
	got, err := f.FindEntry(txCtx, "/buckets/mybucket/dir/a.txt")
	require.NoError(t, err)
	assert.False(t, got.IsInRemoteOnly())

	// a read inside the transaction keeps the fetch: a target the filer only
	// holds on the remote is still seen by a rename's target check
	entry, err := f.FindEntry(txCtx, "/buckets/mybucket/dir/b.txt")
	require.NoError(t, err)
	require.NotNil(t, entry)
	assert.True(t, entry.IsInRemoteOnly())
	assert.NotZero(t, countingStub.statCalls)

	// an exclusive create inside the transaction still sees the remote object
	excl := &Entry{FullPath: "/buckets/mybucket/dir/c.txt", Attr: Attr{Mode: 0644, Mtime: time.Now(), Crtime: time.Now()}}
	err = f.CreateEntry(txCtx, excl, nil, true, false, nil, false, f.MaxFilenameLength)
	assert.ErrorIs(t, err, filer_pb.ErrEntryAlreadyExists)

	// outside a transaction a create still consults the remote
	statCalls := countingStub.statCalls
	plain := &Entry{FullPath: "/buckets/mybucket/dir/d.txt", Attr: Attr{Mode: 0644, Mtime: time.Now(), Crtime: time.Now()}}
	require.NoError(t, f.CreateEntry(context.Background(), plain, nil, false, false, nil, false, f.MaxFilenameLength))
	assert.Greater(t, countingStub.statCalls, statCalls)
}

func TestMaybeLazyFetchFromRemote_GuardedClientRejectsEndpoint(t *testing.T) {
	const storageType = "stub_lazy_guarded"
	countingStub := &countingRemoteClient{
		stubRemoteClient: stubRemoteClient{
			statResult: &filer_pb.RemoteEntry{RemoteMtime: 1, RemoteSize: 1},
		},
	}
	defer registerStubMaker(t, storageType, countingStub)()

	conf := &remote_pb.RemoteConf{Name: "guardedstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "guardedstore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)
	f.BuildGuardedRemoteClient = func(ctx context.Context, _ *remote_pb.RemoteConf, _ bool) (remote_storage.RemoteStorageClient, error) {
		return nil, fmt.Errorf("reject remote endpoint")
	}

	entry, err := f.maybeLazyFetchFromRemote(context.Background(), "/buckets/mybucket/file.txt")
	require.NoError(t, err)
	assert.Nil(t, entry, "guarded rejection should yield no entry")
	assert.Equal(t, 0, countingStub.statCalls, "guarded rejection should not reach the remote")
}

func TestMaybeLazyListFromRemote_GuardedClientRejectsEndpoint(t *testing.T) {
	const storageType = "stub_lazy_list_guarded"
	stub := &stubRemoteClient{
		listDirFn: func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
			return visitFn("/", "file.txt", false, &filer_pb.RemoteEntry{RemoteSize: 1})
		},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "listguardedstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:                   "listguardedstore",
		Bucket:                 "mybucket",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)
	f.BuildGuardedRemoteClient = func(ctx context.Context, _ *remote_pb.RemoteConf, _ bool) (remote_storage.RemoteStorageClient, error) {
		return nil, fmt.Errorf("reject remote endpoint")
	}

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 0, stub.listDirCalls, "guarded rejection should not reach the remote")
}

func TestDeleteEntryMetaAndData_GuardedClientRejectsRemoteBackedFile(t *testing.T) {
	const storageType = "stub_lazy_delete_guarded"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "deleteguardedstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "deleteguardedstore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/file.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 64,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 64},
	}
	f := newTestFiler(t, store, rs)
	f.BuildGuardedRemoteClient = func(ctx context.Context, _ *remote_pb.RemoteConf, _ bool) (remote_storage.RemoteStorageClient, error) {
		return nil, fmt.Errorf("reject remote endpoint")
	}

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.Error(t, err, "guarded rejection should block the remote-backed delete")
	assert.Len(t, stub.deleteCalls, 0, "guarded rejection should not reach the remote")
}

func TestDeleteEntryMetaAndData_GuardedClientAllowsLocalOnlyFile(t *testing.T) {
	const storageType = "stub_lazy_delete_local_only"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "localonlystore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "localonlystore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/file.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 64,
		},
		// no Remote: a local-only file under the mount needs no remote delete
	}
	f := newTestFiler(t, store, rs)
	f.BuildGuardedRemoteClient = func(ctx context.Context, _ *remote_pb.RemoteConf, _ bool) (remote_storage.RemoteStorageClient, error) {
		return nil, fmt.Errorf("reject remote endpoint")
	}

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.NoError(t, err, "local-only file should delete despite a rejected mount endpoint")
	_, findErr := store.FindEntry(context.Background(), filePath)
	require.ErrorIs(t, findErr, filer_pb.ErrNotFound, "local metadata should be deleted")
	assert.Len(t, stub.deleteCalls, 0, "local-only file should not reach the remote")
}

func TestFindEntry_LazyFetchOnMiss(t *testing.T) {
	const storageType = "stub_lazy_findentry"
	stub := &stubRemoteClient{
		statResult: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 999},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "findentrystore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "findentrystore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	// First lookup: store miss → lazy fetch
	entry, err := f.FindEntry(context.Background(), "/buckets/mybucket/obj.txt")
	require.NoError(t, err, fmt.Sprintf("unexpected err: %v", err))
	require.NotNil(t, entry)
	assert.Equal(t, uint64(999), entry.FileSize)

	// Second lookup: now in store, no remote call needed
	entry2, err2 := f.FindEntry(context.Background(), "/buckets/mybucket/obj.txt")
	require.NoError(t, err2)
	require.NotNil(t, entry2)
	assert.Equal(t, uint64(999), entry2.FileSize)
}

func TestDeleteEntryMetaAndData_RemoteOnlyFileDeletesRemoteAndMetadata(t *testing.T) {
	const storageType = "stub_lazy_delete_file"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "deletestore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "deletestore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/file.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 64,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 64},
	}
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.NoError(t, err)

	_, findErr := store.FindEntry(context.Background(), filePath)
	require.ErrorIs(t, findErr, filer_pb.ErrNotFound)
	require.Len(t, stub.deleteCalls, 1)
	assert.Equal(t, "deletestore", stub.deleteCalls[0].Name)
	assert.Equal(t, "mybucket", stub.deleteCalls[0].Bucket)
	assert.Equal(t, "/file.txt", stub.deleteCalls[0].Path)
}

func TestDeleteEntryMetaAndData_IsFromOtherClusterSkipsRemoteDelete(t *testing.T) {
	const storageType = "stub_lazy_delete_other_cluster"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "othercluster", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "othercluster",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/replicated.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 64,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 64},
	}
	f := newTestFiler(t, store, rs)

	// isFromOtherCluster=true simulates a replicated delete from another filer
	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, true, nil, time.Time{})
	require.NoError(t, err)

	// Local metadata should be deleted
	_, findErr := store.FindEntry(context.Background(), filePath)
	require.ErrorIs(t, findErr, filer_pb.ErrNotFound)
	// Remote should NOT have been called — the originating filer handles that
	require.Len(t, stub.deleteCalls, 0)
	require.Len(t, stub.removeCalls, 0)
}

func TestDeleteEntryMetaAndData_UnmountedDirectorySkipsRemoteDelete(t *testing.T) {
	const storageType = "stub_lazy_unmounted"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	store := newStubFilerStore()
	confContent, err := proto.Marshal(&remote_pb.RemoteConf{Name: "cloud1", Type: storageType})
	require.NoError(t, err)
	putConfigEntry(store, DirectoryEtcRemote+"/cloud1"+REMOTE_STORAGE_CONF_SUFFIX, confContent)
	mountedContent, err := proto.Marshal(&remote_pb.RemoteStorageMapping{
		Mappings: map[string]*remote_pb.RemoteStorageLocation{
			"/buckets/mybucket": {Name: "cloud1", Bucket: "mybucket", Path: "/"},
		},
	})
	require.NoError(t, err)
	putConfigEntry(store, DirectoryEtcRemote+"/"+REMOTE_STORAGE_MOUNT_FILE, mountedContent)

	filePath := util.FullPath("/buckets/mybucket/cached.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 64,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 64},
	}

	f := newTestFiler(t, store, NewFilerRemoteStorage())
	f.LoadRemoteStorageConfAndMapping()
	_, remoteLoc := f.RemoteStorage.FindMountDirectory(filePath)
	require.NotNil(t, remoteLoc)

	unmountedContent, err := proto.Marshal(&remote_pb.RemoteStorageMapping{})
	require.NoError(t, err)
	putConfigEntry(store, DirectoryEtcRemote+"/"+REMOTE_STORAGE_MOUNT_FILE, unmountedContent)
	f.onMetadataChangeEvent(&filer_pb.SubscribeMetadataResponse{
		Directory: DirectoryEtcRemote,
		EventNotification: &filer_pb.EventNotification{
			NewEntry: &filer_pb.Entry{Name: REMOTE_STORAGE_MOUNT_FILE, Content: unmountedContent},
		},
	})
	_, remoteLoc = f.RemoteStorage.FindMountDirectory(filePath)
	require.Nil(t, remoteLoc)

	require.NoError(t, f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, true, false, nil, time.Time{}))
	require.Len(t, stub.deleteCalls, 0)
	require.Len(t, stub.removeCalls, 0)
}

func TestDeleteEntryMetaAndData_RemoteOnlyFileNotUnderMountSkipsRemoteDelete(t *testing.T) {
	const storageType = "stub_lazy_delete_not_under_mount"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "notundermount", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "notundermount",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/no/mount/file.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 99,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 99},
	}
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.NoError(t, err)
	require.Len(t, stub.deleteCalls, 0)
}

func TestDeleteEntryMetaAndData_RemoteMountWithoutClientResolutionKeepsMetadata(t *testing.T) {
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf["missingclient"] = &remote_pb.RemoteConf{Name: "missingclient", Type: "stub_missing_client"}
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "missingclient",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/no-client.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 51,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 51},
	}
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.Error(t, err)
	require.ErrorContains(t, err, "resolve remote storage client")
	require.ErrorContains(t, err, string(filePath))

	stored, findErr := store.FindEntry(context.Background(), filePath)
	require.NoError(t, findErr)
	require.NotNil(t, stored)
}

func TestDeleteEntryMetaAndData_LocalDeleteFailurePreservesMetadata(t *testing.T) {
	const storageType = "stub_lazy_delete_local_fail"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "localfail", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "localfail",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/localfail.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 80,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 80},
	}
	store.deleteErrByPath[string(filePath)] = errors.New("simulated local delete failure")
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.Error(t, err)
	require.ErrorContains(t, err, "filer store delete")
	require.Len(t, stub.deleteCalls, 1)

	// Local metadata should still exist since local delete failed
	stored, findErr := store.FindEntry(context.Background(), filePath)
	require.NoError(t, findErr)
	require.NotNil(t, stored)
}

func TestDeleteEntryMetaAndData_RemoteDeleteNotFoundStillDeletesMetadata(t *testing.T) {
	const storageType = "stub_lazy_delete_notfound"
	stub := &stubRemoteClient{deleteErr: remote_storage.ErrRemoteObjectNotFound}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "deletenotfound", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "deletenotfound",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/notfound.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 23,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 23},
	}
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.NoError(t, err)
	_, findErr := store.FindEntry(context.Background(), filePath)
	require.ErrorIs(t, findErr, filer_pb.ErrNotFound)
}

func TestDeleteEntryMetaAndData_RemoteDeleteErrorKeepsMetadata(t *testing.T) {
	const storageType = "stub_lazy_delete_error"
	stub := &stubRemoteClient{deleteErr: errors.New("remote delete failed")}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "deleteerr", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "deleteerr",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	filePath := util.FullPath("/buckets/mybucket/error.txt")
	store.entries[string(filePath)] = &Entry{
		FullPath: filePath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 77,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 77},
	}
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), filePath, false, false, false, false, nil, time.Time{})
	require.Error(t, err)
	stored, findErr := store.FindEntry(context.Background(), filePath)
	require.NoError(t, findErr)
	require.NotNil(t, stored)
}

func TestDeleteEntryMetaAndData_DirectoryUnderMountDeletesRemoteDirectory(t *testing.T) {
	const storageType = "stub_lazy_delete_dir"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "dirstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "dirstore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	dirPath := util.FullPath("/buckets/mybucket/dir")
	store.entries[string(dirPath)] = &Entry{
		FullPath: dirPath,
		Attr: Attr{
			Mtime:  time.Unix(1700000000, 0),
			Crtime: time.Unix(1700000000, 0),
			Mode:   os.ModeDir | 0755,
		},
	}
	f := newTestFiler(t, store, rs)

	err := f.doDeleteEntryMetaAndData(context.Background(), store.entries[string(dirPath)], false, false, nil)
	require.NoError(t, err)

	require.Len(t, stub.removeCalls, 1)
	assert.Equal(t, "dirstore", stub.removeCalls[0].Name)
	assert.Equal(t, "mybucket", stub.removeCalls[0].Bucket)
	assert.Equal(t, "/dir", stub.removeCalls[0].Path)
	_, findErr := store.FindEntry(context.Background(), dirPath)
	require.ErrorIs(t, findErr, filer_pb.ErrNotFound)
}

func TestDeleteEntryMetaAndData_RecursiveFolderDeleteRemotesChildren(t *testing.T) {
	const storageType = "stub_lazy_delete_folder_children"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "childstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "childstore",
		Bucket: "mybucket",
		Path:   "/",
	})

	store := newStubFilerStore()
	dirPath := util.FullPath("/buckets/mybucket/subdir")
	store.entries[string(dirPath)] = &Entry{
		FullPath: dirPath,
		Attr: Attr{
			Mtime:  time.Unix(1700000000, 0),
			Crtime: time.Unix(1700000000, 0),
			Mode:   os.ModeDir | 0755,
		},
	}
	childPath := util.FullPath("/buckets/mybucket/subdir/child.txt")
	store.entries[string(childPath)] = &Entry{
		FullPath: childPath,
		Attr: Attr{
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1700000000, 0),
			Mode:     0644,
			FileSize: 50,
		},
		Remote: &filer_pb.RemoteEntry{RemoteMtime: 1700000000, RemoteSize: 50},
	}
	f := newTestFiler(t, store, rs)

	err := f.DeleteEntryMetaAndData(context.Background(), dirPath, true, false, false, false, nil, time.Time{})
	require.NoError(t, err)

	// Child file should have been deleted from remote
	require.Len(t, stub.deleteCalls, 1)
	assert.Equal(t, "/subdir/child.txt", stub.deleteCalls[0].Path)
	// Directory itself should also have been deleted from remote
	require.Len(t, stub.removeCalls, 1)
	assert.Equal(t, "/subdir", stub.removeCalls[0].Path)
}

// --- lazy listing tests ---

func TestMaybeLazyListFromRemote_PopulatesStoreFromRemote(t *testing.T) {
	const storageType = "stub_lazy_list_populate"
	stub := &stubRemoteClient{
		listDirFn: func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
			if err := visitFn("/", "subdir", true, nil); err != nil {
				return err
			}
			if err := visitFn("/", "file.txt", false, &filer_pb.RemoteEntry{
				RemoteMtime:           1700000000,
				RemoteSize:            42,
				RemoteETag:            "abc",
				StorageName:           "myliststore",
				RemoteContentEncoding: proto.String("gzip"),
			}); err != nil {
				return err
			}
			return nil
		},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "myliststore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:                   "myliststore",
		Bucket:                 "mybucket",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 1, stub.listDirCalls)

	// Check that the file was persisted
	fileEntry := store.getEntry("/buckets/mybucket/file.txt")
	require.NotNil(t, fileEntry, "file.txt should be persisted")
	assert.Equal(t, uint64(42), fileEntry.FileSize)
	assert.NotNil(t, fileEntry.Remote)
	assert.Equal(t, []byte("gzip"), fileEntry.Extended["Content-Encoding"])

	// Check that the subdirectory was persisted
	dirEntry := store.getEntry("/buckets/mybucket/subdir")
	require.NotNil(t, dirEntry, "subdir should be persisted")
	assert.True(t, dirEntry.IsDirectory())
}

func TestMaybeLazyListFromRemote_DisabledWhenTTLZero(t *testing.T) {
	const storageType = "stub_lazy_list_disabled"
	stub := &stubRemoteClient{
		listDirFn: func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
			return visitFn("/", "file.txt", false, &filer_pb.RemoteEntry{
				RemoteMtime: 1700000000, RemoteSize: 10,
			})
		},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "disabledstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:   "disabledstore",
		Bucket: "mybucket",
		Path:   "/",
		// ListingCacheTtlSeconds defaults to 0 → disabled
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 0, stub.listDirCalls, "should not call remote when TTL is 0")
}

func TestMaybeLazyListFromRemote_TTLCachePreventsSecondCall(t *testing.T) {
	const storageType = "stub_lazy_list_ttl"
	stub := &stubRemoteClient{
		listDirFn: func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
			return visitFn("/", "file.txt", false, &filer_pb.RemoteEntry{
				RemoteMtime: 1700000000, RemoteSize: 10,
			})
		},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "ttlstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:                   "ttlstore",
		Bucket:                 "mybucket",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	// First call should hit remote
	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 1, stub.listDirCalls)

	// Second call within TTL should be a no-op
	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 1, stub.listDirCalls, "should not call remote again within TTL")
}

func TestMaybeLazyListFromRemote_NotUnderMount(t *testing.T) {
	rs := NewFilerRemoteStorage()
	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/not/a/mount"))
}

func TestMaybeLazyListFromRemote_SkipsLocalOnlyEntries(t *testing.T) {
	const storageType = "stub_lazy_list_skiplocal"
	stub := &stubRemoteClient{
		listDirFn: func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
			// Remote has a file called "local.txt" too
			return visitFn("/", "local.txt", false, &filer_pb.RemoteEntry{
				RemoteMtime: 1700000000, RemoteSize: 99,
			})
		},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "skipstore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:                   "skipstore",
		Bucket:                 "mybucket",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	store := newStubFilerStore()
	// Pre-populate a local-only entry (no Remote field)
	store.entries["/buckets/mybucket/local.txt"] = &Entry{
		FullPath: "/buckets/mybucket/local.txt",
		Attr:     Attr{Mode: 0644, FileSize: 50},
	}
	f := newTestFiler(t, store, rs)

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))

	// Local entry should NOT have been overwritten
	localEntry := store.getEntry("/buckets/mybucket/local.txt")
	require.NotNil(t, localEntry)
	assert.Equal(t, uint64(50), localEntry.FileSize, "local-only entry should not be overwritten")
	assert.Nil(t, localEntry.Remote, "local-only entry should keep nil Remote")
}

func TestMaybeLazyListFromRemote_MergesExistingRemoteEntry(t *testing.T) {
	const storageType = "stub_lazy_list_merge"
	stub := &stubRemoteClient{
		listDirFn: func(loc *remote_pb.RemoteStorageLocation, visitFn remote_storage.VisitFunc) error {
			return visitFn("/", "cached.txt", false, &filer_pb.RemoteEntry{
				RemoteMtime: 1700000099, // updated mtime
				RemoteSize:  200,        // updated size
				RemoteETag:  "new-etag",
				StorageName: "mergestore",
			})
		},
	}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "mergestore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:                   "mergestore",
		Bucket:                 "mybucket",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	store := newStubFilerStore()
	// Pre-populate an existing remote-backed entry with chunks and extended attrs
	existingChunks := []*filer_pb.FileChunk{
		{FileId: "1,abc123", Size: 100, Offset: 0},
	}
	store.entries["/buckets/mybucket/cached.txt"] = &Entry{
		FullPath: "/buckets/mybucket/cached.txt",
		Attr: Attr{
			Mode:     0644,
			FileSize: 100,
			Uid:      1000,
			Gid:      1000,
			Mtime:    time.Unix(1700000000, 0),
			Crtime:   time.Unix(1699000000, 0),
		},
		Chunks: existingChunks,
		Extended: map[string][]byte{
			"user.custom": []byte("myvalue"),
		},
		Remote: &filer_pb.RemoteEntry{
			RemoteMtime: 1700000000,
			RemoteSize:  100,
			RemoteETag:  "old-etag",
			StorageName: "mergestore",
		},
	}
	f := newTestFiler(t, store, rs)

	f.maybeLazyListFromRemote(context.Background(), util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 1, stub.listDirCalls)

	merged := store.getEntry("/buckets/mybucket/cached.txt")
	require.NotNil(t, merged)

	// Remote metadata should be updated
	assert.Equal(t, int64(1700000099), merged.Remote.RemoteMtime)
	assert.Equal(t, int64(200), merged.Remote.RemoteSize)
	assert.Equal(t, "new-etag", merged.Remote.RemoteETag)
	assert.Equal(t, uint64(200), merged.FileSize)
	assert.Equal(t, time.Unix(1700000099, 0), merged.Mtime)

	// Local state should be preserved
	assert.Equal(t, existingChunks, merged.Chunks, "chunks must be preserved")
	assert.Equal(t, []byte("myvalue"), merged.Extended["user.custom"], "extended attrs must be preserved")
	assert.Equal(t, uint32(1000), merged.Uid, "uid must be preserved")
	assert.Equal(t, uint32(1000), merged.Gid, "gid must be preserved")
	assert.Equal(t, os.FileMode(0644), merged.Mode, "mode must be preserved")
	assert.Equal(t, time.Unix(1699000000, 0), merged.Crtime, "crtime must be preserved")
}

func TestMaybeLazyListFromRemote_ContextGuardPreventsRecursion(t *testing.T) {
	const storageType = "stub_lazy_list_guard"
	stub := &stubRemoteClient{}
	defer registerStubMaker(t, storageType, stub)()

	conf := &remote_pb.RemoteConf{Name: "guardliststore", Type: storageType}
	rs := NewFilerRemoteStorage()
	rs.storageNameToConf[conf.Name] = conf
	rs.mapDirectoryToRemoteStorage("/buckets/mybucket", &remote_pb.RemoteStorageLocation{
		Name:                   "guardliststore",
		Bucket:                 "mybucket",
		Path:                   "/",
		ListingCacheTtlSeconds: 300,
	})

	store := newStubFilerStore()
	f := newTestFiler(t, store, rs)

	// With lazyListContextKey set, should be a no-op
	guardCtx := context.WithValue(context.Background(), lazyListContextKey{}, true)
	f.maybeLazyListFromRemote(guardCtx, util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 0, stub.listDirCalls)

	// With lazyFetchContextKey set, should also be a no-op
	fetchCtx := context.WithValue(context.Background(), lazyFetchContextKey{}, true)
	f.maybeLazyListFromRemote(fetchCtx, util.FullPath("/buckets/mybucket"))
	assert.Equal(t, 0, stub.listDirCalls)
}