// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package gc_test

import (
	"context"
	"errors"
	"testing"
	"time"

	"github.com/stretchr/testify/require"
	"go.uber.org/zap"
	"go.uber.org/zap/zaptest"

	"storj.io/common/base58"
	"storj.io/common/encryption"
	"storj.io/common/memory"
	"storj.io/common/paths"
	"storj.io/common/pb"
	"storj.io/common/storj"
	"storj.io/common/testcontext"
	"storj.io/common/testrand"
	"storj.io/storj/private/testplanet"
	"storj.io/storj/satellite/gc/bloomfilter"
	"storj.io/storj/satellite/metabase"
	"storj.io/storj/satellite/metabase/rangedloop"
	"storj.io/storj/storagenode"
	"storj.io/storj/storagenode/blobstore"
	"storj.io/uplink/private/eestream"
	"storj.io/uplink/private/testuplink"
)

// TestGarbageCollection does the following:
// * Set up a network with one storagenode
// * Upload two objects
// * Delete one object from the metainfo service on the satellite
// * Do bloom filter generation
// * Send out bloom filters
// * Check that pieces of the deleted object are deleted on the storagenode
// * Check that pieces of the kept object are not deleted on the storagenode.
func TestGarbageCollection(t *testing.T) {
	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 2, StorageNodeCount: 1, UplinkCount: 1,
		Reconfigure: testplanet.Reconfigure{
			StorageNode: func(index int, config *storagenode.Config) {
				config.Retain.MaxTimeSkew = 0
			},
		},
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		// Set satellite 1 to store bloom filters of satellite 0
		access := planet.Uplinks[0].Access[planet.Satellites[1].NodeURL().ID]
		accessString, err := access.Serialize()
		require.NoError(t, err)

		// configure sender
		gcsender := planet.Satellites[0].GarbageCollection.Sender
		gcsender.Config.AccessGrant = accessString

		// configure filter uploader
		config := planet.Satellites[0].Config.GarbageCollectionBF
		config.AccessGrant = accessString

		satellite := planet.Satellites[0]
		upl := planet.Uplinks[0]
		targetNode := planet.StorageNodes[0]

		// Upload two objects
		testData1 := testrand.Bytes(8 * memory.KiB)
		testData2 := testrand.Bytes(8 * memory.KiB)

		err = upl.Upload(ctx, satellite, "testbucket", "test/path/1", testData1)
		require.NoError(t, err)

		objectLocationToDelete, segmentToDelete := getSegment(ctx, t, satellite, upl, "testbucket", "test/path/1")

		var deletedPieceID storj.PieceID
		for _, p := range segmentToDelete.Pieces {
			if p.StorageNode == targetNode.ID() {
				deletedPieceID = segmentToDelete.RootPieceID.Derive(p.StorageNode, int32(p.Number))
				break
			}
		}
		require.NotZero(t, deletedPieceID)

		err = upl.Upload(ctx, satellite, "testbucket", "test/path/2", testData2)
		require.NoError(t, err)
		_, segmentToKeep := getSegment(ctx, t, satellite, upl, "testbucket", "test/path/2")
		var keptPieceID storj.PieceID
		for _, p := range segmentToKeep.Pieces {
			if p.StorageNode == targetNode.ID() {
				keptPieceID = segmentToKeep.RootPieceID.Derive(p.StorageNode, int32(p.Number))
				break
			}
		}
		require.NotZero(t, keptPieceID)

		// Delete one object from metainfo service on satellite
		_, err = satellite.Metabase.DB.DeleteObjectExactVersion(ctx, metabase.DeleteObjectExactVersion{
			ObjectLocation: objectLocationToDelete,
			Version:        metabase.DefaultVersion,
		})
		require.NoError(t, err)

		// Check that piece of the deleted object is on the storagenode
		pieceAccess, err := targetNode.DB.Pieces().Stat(ctx, blobstore.BlobRef{
			Namespace: satellite.ID().Bytes(),
			Key:       deletedPieceID.Bytes(),
		})
		require.NoError(t, err)
		require.NotNil(t, pieceAccess)

		// The pieceInfo.GetPieceIDs query converts piece creation and the filter creation timestamps
		// to datetime in sql. This chops off all precision beyond seconds.
		// In this test, the amount of time that elapses between piece uploads and the gc loop might be
		// less than a second, meaning datetime(piece_creation) < datetime(filter_creation) is false unless we sleep
		// for a second.
		time.Sleep(1 * time.Second)

		// Wait for bloom filter observer to finish
		rangedloopConfig := planet.Satellites[0].Config.RangedLoop

		observer := bloomfilter.NewObserver(zaptest.NewLogger(t), config, planet.Satellites[0].Overlay.DB)
		segments := rangedloop.NewMetabaseRangeSplitter(planet.Satellites[0].Metabase.DB, rangedloopConfig.AsOfSystemInterval, rangedloopConfig.BatchSize)
		rangedLoop := rangedloop.NewService(zap.NewNop(), planet.Satellites[0].Config.RangedLoop, segments,
			[]rangedloop.Observer{observer})

		_, err = rangedLoop.RunOnce(ctx)
		require.NoError(t, err)

		// send to storagenode
		err = gcsender.RunOnce(ctx)
		require.NoError(t, err)

		// Wait for the storagenode's RetainService queue to be empty
		targetNode.Storage2.RetainService.TestWaitUntilEmpty()

		// Check that piece of the deleted object is not on the storagenode
		pieceAccess, err = targetNode.DB.Pieces().Stat(ctx, blobstore.BlobRef{
			Namespace: satellite.ID().Bytes(),
			Key:       deletedPieceID.Bytes(),
		})
		require.Error(t, err)
		require.Nil(t, pieceAccess)

		// Check that piece of the kept object is on the storagenode
		pieceAccess, err = targetNode.DB.Pieces().Stat(ctx, blobstore.BlobRef{
			Namespace: satellite.ID().Bytes(),
			Key:       keptPieceID.Bytes(),
		})
		require.NoError(t, err)
		require.NotNil(t, pieceAccess)
	})
}

// TestGarbageCollectionWithCopies checkes that server-side copy elements are not
// affecting GC and nothing unexpected was deleted from storage nodes.
func TestGarbageCollectionWithCopies(t *testing.T) {
	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 1, StorageNodeCount: 4, UplinkCount: 1,
		Reconfigure: testplanet.Reconfigure{
			Satellite: testplanet.ReconfigureRS(2, 3, 4, 4),
		},
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		satellite := planet.Satellites[0]

		access := planet.Uplinks[0].Access[planet.Satellites[0].NodeURL().ID]
		accessString, err := access.Serialize()
		require.NoError(t, err)

		gcsender := planet.Satellites[0].GarbageCollection.Sender
		gcsender.Config.AccessGrant = accessString

		// configure filter uploader
		config := planet.Satellites[0].Config.GarbageCollectionBF
		config.AccessGrant = accessString

		project, err := planet.Uplinks[0].OpenProject(ctx, satellite)
		require.NoError(t, err)
		defer ctx.Check(project.Close)

		allSpaceUsedForPieces := func() (all int64) {
			for _, node := range planet.StorageNodes {
				_, piecesContent, _, err := node.Storage2.Store.SpaceUsedTotalAndBySatellite(ctx)
				require.NoError(t, err)
				all += piecesContent
			}
			return all
		}

		expectedRemoteData := testrand.Bytes(8 * memory.KiB)
		expectedInlineData := testrand.Bytes(1 * memory.KiB)

		encryptedSize, err := encryption.CalcEncryptedSize(int64(len(expectedRemoteData)), storj.EncryptionParameters{
			CipherSuite: storj.EncAESGCM,
			BlockSize:   29 * 256 * memory.B.Int32(), // hardcoded value from uplink
		})
		require.NoError(t, err)

		redundancyStrategy, err := planet.Satellites[0].Config.Metainfo.RS.RedundancyStrategy()
		require.NoError(t, err)

		pieceSize := eestream.CalcPieceSize(encryptedSize, redundancyStrategy.ErasureScheme)
		singleRemoteUsed := pieceSize * int64(len(planet.StorageNodes))
		totalUsedByNodes := 2 * singleRemoteUsed // two remote objects

		require.NoError(t, planet.Uplinks[0].Upload(ctx, satellite, "testbucket", "remote", expectedRemoteData))
		require.NoError(t, planet.Uplinks[0].Upload(ctx, satellite, "testbucket", "inline", expectedInlineData))
		require.NoError(t, planet.Uplinks[0].Upload(ctx, satellite, "testbucket", "remote-no-copy", expectedRemoteData))

		_, err = project.CopyObject(ctx, "testbucket", "remote", "testbucket", "remote-copy", nil)
		require.NoError(t, err)
		_, err = project.CopyObject(ctx, "testbucket", "inline", "testbucket", "inline-copy", nil)
		require.NoError(t, err)

		require.NoError(t, planet.WaitForStorageNodeEndpoints(ctx))

		afterTotalUsedByNodes := allSpaceUsedForPieces()
		require.Equal(t, totalUsedByNodes, afterTotalUsedByNodes)

		// Wait for bloom filter observer to finish
		rangedloopConfig := planet.Satellites[0].Config.RangedLoop

		observer := bloomfilter.NewObserver(zaptest.NewLogger(t), config, planet.Satellites[0].Overlay.DB)
		segments := rangedloop.NewMetabaseRangeSplitter(planet.Satellites[0].Metabase.DB, rangedloopConfig.AsOfSystemInterval, rangedloopConfig.BatchSize)
		rangedLoop := rangedloop.NewService(zap.NewNop(), planet.Satellites[0].Config.RangedLoop, segments,
			[]rangedloop.Observer{observer})

		_, err = rangedLoop.RunOnce(ctx)
		require.NoError(t, err)

		// send to storagenode
		err = gcsender.RunOnce(ctx)
		require.NoError(t, err)

		for _, node := range planet.StorageNodes {
			node.Storage2.RetainService.TestWaitUntilEmpty()
		}

		// we should see all space used by all objects
		afterTotalUsedByNodes = allSpaceUsedForPieces()
		require.Equal(t, totalUsedByNodes, afterTotalUsedByNodes)

		for _, toDelete := range []string{
			// delete ancestors, no change in used space
			"remote",
			"inline",
			// delete object without copy, used space should be decreased
			"remote-no-copy",
		} {
			_, err = project.DeleteObject(ctx, "testbucket", toDelete)
			require.NoError(t, err)
		}

		planet.WaitForStorageNodeDeleters(ctx)

		// run GC
		_, err = rangedLoop.RunOnce(ctx)
		require.NoError(t, err)

		// send to storagenode
		err = gcsender.RunOnce(ctx)
		require.NoError(t, err)

		for _, node := range planet.StorageNodes {
			node.Storage2.RetainService.TestWaitUntilEmpty()
		}

		// verify that we deleted only pieces for "remote-no-copy" object
		afterTotalUsedByNodes = allSpaceUsedForPieces()
		require.Equal(t, totalUsedByNodes, afterTotalUsedByNodes)

		// delete rest of objects to verify that everything will be removed also from SNs
		for _, toDelete := range []string{
			"remote-copy",
			"inline-copy",
		} {
			_, err = project.DeleteObject(ctx, "testbucket", toDelete)
			require.NoError(t, err)
		}

		planet.WaitForStorageNodeDeleters(ctx)

		// run GC
		_, err = rangedLoop.RunOnce(ctx)
		require.NoError(t, err)

		// send to storagenode
		err = gcsender.RunOnce(ctx)
		require.NoError(t, err)

		for _, node := range planet.StorageNodes {
			node.Storage2.RetainService.TestWaitUntilEmpty()
		}

		// verify that nothing more was deleted from storage nodes after GC
		afterTotalUsedByNodes = allSpaceUsedForPieces()
		require.EqualValues(t, totalUsedByNodes, afterTotalUsedByNodes)
	})
}

func getSegment(ctx *testcontext.Context, t *testing.T, satellite *testplanet.Satellite, upl *testplanet.Uplink, bucket, path string) (_ metabase.ObjectLocation, _ metabase.Segment) {
	access := upl.Access[satellite.ID()]

	serializedAccess, err := access.Serialize()
	require.NoError(t, err)

	store, err := encryptionAccess(serializedAccess)
	require.NoError(t, err)

	encryptedPath, err := encryption.EncryptPathWithStoreCipher(bucket, paths.NewUnencrypted(path), store)
	require.NoError(t, err)

	objectLocation :=
		metabase.ObjectLocation{
			ProjectID:  upl.Projects[0].ID,
			BucketName: "testbucket",
			ObjectKey:  metabase.ObjectKey(encryptedPath.Raw()),
		}

	lastSegment, err := satellite.Metabase.DB.GetLatestObjectLastSegment(ctx, metabase.GetLatestObjectLastSegment{
		ObjectLocation: objectLocation,
	})
	require.NoError(t, err)

	return objectLocation, lastSegment
}

func encryptionAccess(access string) (*encryption.Store, error) {
	data, version, err := base58.CheckDecode(access)
	if err != nil || version != 0 {
		return nil, errors.New("invalid access grant format")
	}

	p := new(pb.Scope)
	if err := pb.Unmarshal(data, p); err != nil {
		return nil, err
	}

	key, err := storj.NewKey(p.EncryptionAccess.DefaultKey)
	if err != nil {
		return nil, err
	}

	store := encryption.NewStore()
	store.SetDefaultKey(key)
	store.SetDefaultPathCipher(storj.EncAESGCM)

	return store, nil
}

// TestGarbageCollection_PendingObject verifies that segments from pending objects
// are also processed by GC piece tracker.
func TestGarbageCollection_PendingObject(t *testing.T) {
	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 1, StorageNodeCount: 1, UplinkCount: 1,
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		access := planet.Uplinks[0].Access[planet.Satellites[0].ID()]
		accessString, err := access.Serialize()
		require.NoError(t, err)

		satellite := planet.Satellites[0]
		upl := planet.Uplinks[0]

		testData := testrand.Bytes(15 * memory.KiB)
		pendingStreamID := startMultipartUpload(ctx, t, upl, satellite, "testbucket", "multi", testData)

		segments, err := satellite.Metabase.DB.TestingAllSegments(ctx)
		require.NoError(t, err)
		require.Len(t, segments, 1)

		config := planet.Satellites[0].Config.GarbageCollectionBF
		config.AccessGrant = accessString
		config.Bucket = "bucket"
		config.FalsePositiveRate = 0.000000001
		config.InitialPieces = 10

		observer := bloomfilter.NewObserver(satellite.Log.Named("gc observer"), config, satellite.Overlay.DB)

		rangedloopConfig := planet.Satellites[0].Config.RangedLoop
		provider := rangedloop.NewMetabaseRangeSplitter(planet.Satellites[0].Metabase.DB, rangedloopConfig.AsOfSystemInterval, rangedloopConfig.BatchSize)
		rangedLoop := rangedloop.NewService(zap.NewNop(), planet.Satellites[0].Config.RangedLoop, provider,
			[]rangedloop.Observer{observer})

		_, err = rangedLoop.RunOnce(ctx)
		require.NoError(t, err)

		require.NotEmpty(t, observer.TestingRetainInfos())
		info := observer.TestingRetainInfos()[planet.StorageNodes[0].ID()]
		require.NotNil(t, info)
		require.Equal(t, 1, info.Count)

		completeMultipartUpload(ctx, t, upl, satellite, "testbucket", "multi", pendingStreamID)
		gotData, err := upl.Download(ctx, satellite, "testbucket", "multi")
		require.NoError(t, err)
		require.Equal(t, testData, gotData)
	})
}

func startMultipartUpload(ctx context.Context, t *testing.T, uplink *testplanet.Uplink, satellite *testplanet.Satellite, bucketName string, path storj.Path, data []byte) string {
	_, found := testuplink.GetMaxSegmentSize(ctx)
	if !found {
		ctx = testuplink.WithMaxSegmentSize(ctx, satellite.Config.Metainfo.MaxSegmentSize)
	}

	project, err := uplink.GetProject(ctx, satellite)
	require.NoError(t, err)
	defer func() { require.NoError(t, project.Close()) }()

	_, err = project.EnsureBucket(ctx, bucketName)
	require.NoError(t, err)

	info, err := project.BeginUpload(ctx, bucketName, path, nil)
	require.NoError(t, err)

	upload, err := project.UploadPart(ctx, bucketName, path, info.UploadID, 1)
	require.NoError(t, err)
	_, err = upload.Write(data)
	require.NoError(t, err)
	require.NoError(t, upload.Commit())

	return info.UploadID
}

func completeMultipartUpload(ctx context.Context, t *testing.T, uplink *testplanet.Uplink, satellite *testplanet.Satellite, bucketName string, path storj.Path, streamID string) {
	_, found := testuplink.GetMaxSegmentSize(ctx)
	if !found {
		ctx = testuplink.WithMaxSegmentSize(ctx, satellite.Config.Metainfo.MaxSegmentSize)
	}

	project, err := uplink.GetProject(ctx, satellite)
	require.NoError(t, err)
	defer func() { require.NoError(t, project.Close()) }()

	_, err = project.CommitUpload(ctx, bucketName, path, streamID, nil)
	require.NoError(t, err)
}