// No matter what order timestamp and snapshot is loaded, if the snapshot's checksum doesn't match
// what's in the timestamp, the builder will error and refuse to load the latest piece of metadata
// whether that is snapshot (because it was loaded after timestamp) or timestamp (because builder
// retroactive checks the loaded snapshot's checksum).  Timestamp ONLY checks the snapshot checksum.
func TestTimestampPreAndPostChecksumming(t *testing.T) {
	gun := "docker.com/notary"
	repo, _, err := testutils.EmptyRepo(gun, "targets/other", "targets/other/other")
	require.NoError(t, err)

	// add invalid checkums for all the other roles to timestamp too, and show that
	// cached items aren't checksummed against this
	fakeChecksum, err := data.NewFileMeta(bytes.NewBuffer([]byte("fake")), notary.SHA256, notary.SHA512)
	require.NoError(t, err)
	for _, roleName := range append(data.BaseRoles, "targets/other") {
		// add a wrong checksum for every role, including timestamp itself
		repo.Timestamp.Signed.Meta[roleName] = fakeChecksum
	}
	// this will overwrite the snapshot checksum with the right one
	meta, err := testutils.SignAndSerialize(repo)
	require.NoError(t, err)
	// ensure that the fake meta for other roles weren't destroyed by signing the timestamp
	require.Len(t, repo.Timestamp.Signed.Meta, 5)

	snapJSON := append(meta[data.CanonicalSnapshotRole], ' ')

	// --- load timestamp first
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	require.NoError(t, builder.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 1, false))
	// timestamp doesn't fail, even though its checksum for root is wrong according to timestamp
	require.NoError(t, builder.Load(data.CanonicalTimestampRole, meta[data.CanonicalTimestampRole], 1, false))
	// loading the snapshot in fails, because of the checksum the timestamp has
	err = builder.Load(data.CanonicalSnapshotRole, snapJSON, 1, false)
	require.Error(t, err)
	require.IsType(t, data.ErrMismatchedChecksum{}, err)
	require.True(t, builder.IsLoaded(data.CanonicalTimestampRole))
	require.False(t, builder.IsLoaded(data.CanonicalSnapshotRole))
	// all the other metadata can be loaded in, even though the checksums are wrong according to timestamp
	for _, roleName := range []string{data.CanonicalTargetsRole, "targets/other"} {
		require.NoError(t, builder.Load(roleName, meta[roleName], 1, false))
	}

	// --- load snapshot first
	builder = tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	for _, roleName := range append(data.BaseRoles, "targets/other") {
		switch roleName {
		case data.CanonicalTimestampRole:
			continue
		case data.CanonicalSnapshotRole:
			require.NoError(t, builder.Load(roleName, snapJSON, 1, false))
		default:
			require.NoError(t, builder.Load(roleName, meta[roleName], 1, false))
		}
	}
	// timestamp fails because the snapshot checksum is wrong
	err = builder.Load(data.CanonicalTimestampRole, meta[data.CanonicalTimestampRole], 1, false)
	require.Error(t, err)
	checksumErr, ok := err.(data.ErrMismatchedChecksum)
	require.True(t, ok)
	require.Contains(t, checksumErr.Error(), "checksum for snapshot did not match")
	require.False(t, builder.IsLoaded(data.CanonicalTimestampRole))
	require.True(t, builder.IsLoaded(data.CanonicalSnapshotRole))
}

// If any other metadata is loaded first, when the snapshot is loaded it will retroactively go back
// and validate that metadata.  If anything fails to validate, or there is metadata for which this
// snapshot has no checksums for, the snapshot will fail to validate.
func TestSnapshotLoadedAfterChecksumsOthersRetroactively(t *testing.T) {
	gun := "docker.com/notary"
	meta := setupSnapshotChecksumming(t, gun)

	// --- load all the other metadata first, but with an extra space at the end which should
	// --- validate fine, except for the checksum.
	for _, roleNameToPermute := range append(data.BaseRoles, "targets/other") {
		builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
		if roleNameToPermute == data.CanonicalSnapshotRole {
			continue
		}
		// load all the roles normally, except for roleToPermute, which has one space added
		// to the end, thus changing the checksum
		for _, roleNameToLoad := range append(data.BaseRoles, "targets/other") {
			switch roleNameToLoad {
			case data.CanonicalSnapshotRole:
				continue // we load this later
			case roleNameToPermute:
				// having a space added at the end should not affect any validity check except checksum
				require.NoError(t, builder.Load(roleNameToLoad, append(meta[roleNameToLoad], ' '), 0, false))
			default:
				require.NoError(t, builder.Load(roleNameToLoad, meta[roleNameToLoad], 1, false))
			}
			require.True(t, builder.IsLoaded(roleNameToLoad))
		}
		// now load the snapshot - it should fail with the checksum failure for the permuted role
		err := builder.Load(data.CanonicalSnapshotRole, meta[data.CanonicalSnapshotRole], 1, false)
		switch roleNameToPermute {
		case data.CanonicalTimestampRole:
			require.NoError(t, err) // we don't check the timestamp's checksum
		default:
			require.Error(t, err)
			checksumErr, ok := err.(data.ErrMismatchedChecksum)
			require.True(t, ok)
			require.Contains(t, checksumErr.Error(), fmt.Sprintf("checksum for %s did not match", roleNameToPermute))
			require.False(t, builder.IsLoaded(data.CanonicalSnapshotRole))
		}
	}

	// load all the metadata as is without alteration (so they should validate all checksums)
	// but also load the metadata that is not contained in the snapshot.  Then when the snapshot
	// is loaded it will fail validation, because it doesn't have target/other/other's checksum
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	for _, roleNameToLoad := range append(data.BaseRoles, "targets/other", "targets/other/other") {
		if roleNameToLoad == data.CanonicalSnapshotRole {
			continue
		}
		require.NoError(t, builder.Load(roleNameToLoad, meta[roleNameToLoad], 1, false))
	}
	err := builder.Load(data.CanonicalSnapshotRole, meta[data.CanonicalSnapshotRole], 1, false)
	require.Error(t, err)
	require.IsType(t, data.ErrMissingMeta{}, err)
}

// If the snapshot is loaded first (-ish, because really root has to be loaded first)
// it will be used to validate the checksums of all other metadata that gets loaded.
// If the checksum doesn't match, or if there is no checksum, then the other metadata
// cannot be loaded.
func TestSnapshotLoadedFirstChecksumsOthers(t *testing.T) {
	gun := "docker.com/notary"
	meta := setupSnapshotChecksumming(t, gun)
	// --- load root then snapshot
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	require.NoError(t, builder.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 1, false))
	require.NoError(t, builder.Load(data.CanonicalSnapshotRole, meta[data.CanonicalSnapshotRole], 1, false))

	// loading timestamp is fine, even though the timestamp metadata has the wrong checksum because
	// we don't check timestamp checksums
	require.NoError(t, builder.Load(data.CanonicalTimestampRole, meta[data.CanonicalTimestampRole], 1, false))

	// loading the other roles' metadata with a space will fail because of a checksum failure (builder
	// checks right away if the snapshot is loaded) - in the case of targets/other/other, which should
	// not be in snapshot at all, loading should fail even without a space because there is no checksum
	// for it
	for _, roleNameToLoad := range []string{data.CanonicalTargetsRole, "targets/other"} {
		err := builder.Load(roleNameToLoad, append(meta[roleNameToLoad], ' '), 0, false)
		require.Error(t, err)
		checksumErr, ok := err.(data.ErrMismatchedChecksum)
		require.True(t, ok)
		require.Contains(t, checksumErr.Error(), fmt.Sprintf("checksum for %s did not match", roleNameToLoad))
		require.False(t, builder.IsLoaded(roleNameToLoad))

		// now load it for real (since we need targets loaded before trying to load "targets/other")
		require.NoError(t, builder.Load(roleNameToLoad, meta[roleNameToLoad], 1, false))
	}
	// loading the non-existent role wil fail
	err := builder.Load("targets/other/other", meta["targets/other/other"], 1, false)
	require.Error(t, err)
	require.IsType(t, data.ErrMissingMeta{}, err)
	require.False(t, builder.IsLoaded("targets/other/other"))
}

// ### generateSnapshot tests ###
func TestGenerateSnapshotRootNotLoaded(t *testing.T) {
	gun := "docker.com/notary"
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	_, err := generateSnapshot(gun, builder, storage.NewMemStorage())
	require.Error(t, err)
	require.IsType(t, validation.ErrValidation{}, err)
}

// CreateTimestamp creates a new timestamp. If a prev timestamp is provided, it
// is assumed this is the immediately previous one, and the new one will have a
// version number one higher than prev. The store is used to lookup the current
// snapshot, this function does not save the newly generated timestamp.
func createTimestamp(gun string, prev *data.SignedTimestamp, snapshot []byte, store storage.MetaStore,
	cryptoService signed.CryptoService) (*storage.MetaUpdate, error) {

	builder := tuf.NewRepoBuilder(gun, cryptoService, trustpinning.TrustPinConfig{})

	// load the current root to ensure we use the correct timestamp key.
	_, root, err := store.GetCurrent(gun, data.CanonicalRootRole)
	if err != nil {
		logrus.Debug("Previous timestamp, but no root for GUN ", gun)
		return nil, err
	}
	if err := builder.Load(data.CanonicalRootRole, root, 1, false); err != nil {
		logrus.Debug("Could not load valid previous root for GUN ", gun)
		return nil, err
	}

	// load snapshot so we can include it in timestamp
	if err := builder.Load(data.CanonicalSnapshotRole, snapshot, 1, false); err != nil {
		logrus.Debug("Could not load valid previous snapshot for GUN ", gun)
		return nil, err
	}

	meta, ver, err := builder.GenerateTimestamp(prev)
	if err != nil {
		return nil, err
	}
	return &storage.MetaUpdate{
		Role:    data.CanonicalTimestampRole,
		Version: ver,
		Data:    meta,
	}, nil
}

// bootstrapRepo loads the repository from the local file system (i.e.
// a not yet published repo or a possibly obsolete local copy) into
// r.tufRepo.  This attempts to load metadata for all roles.  Since server
// snapshots are supported, if the snapshot metadata fails to load, that's ok.
// This assumes that bootstrapRepo is only used by Publish() or RotateKey()
func (r *NotaryRepository) bootstrapRepo() error {
	b := tuf.NewRepoBuilder(r.gun, r.CryptoService, r.trustPinning)

	logrus.Debugf("Loading trusted collection.")

	for _, role := range data.BaseRoles {
		jsonBytes, err := r.fileStore.GetMeta(role, store.NoSizeLimit)
		if err != nil {
			if _, ok := err.(store.ErrMetaNotFound); ok &&
				// server snapshots are supported, and server timestamp management
				// is required, so if either of these fail to load that's ok - especially
				// if the repo is new
				role == data.CanonicalSnapshotRole || role == data.CanonicalTimestampRole {
				continue
			}
			return err
		}
		if err := b.Load(role, jsonBytes, 1, true); err != nil {
			return err
		}
	}

	tufRepo, err := b.Finish()
	if err == nil {
		r.tufRepo = tufRepo
	}
	return nil
}

func TestBuilderOnlyAcceptsDelegationsAfterParent(t *testing.T) {
	meta, gun := getSampleMeta(t)
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})

	// load the root
	require.NoError(t, builder.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 1, false))

	// delegations can't be loaded without target
	for _, delgName := range []string{"targets/a", "targets/a/b"} {
		err := builder.Load(delgName, meta[delgName], 1, false)
		require.Error(t, err)
		require.IsType(t, tuf.ErrInvalidBuilderInput{}, err)
		require.Contains(t, err.Error(), "targets must be loaded first")
		require.False(t, builder.IsLoaded(delgName))
		require.Equal(t, 1, builder.GetLoadedVersion(delgName))
	}

	// load the targets
	require.NoError(t, builder.Load(data.CanonicalTargetsRole, meta[data.CanonicalTargetsRole], 1, false))

	// targets/a/b can't be loaded because targets/a isn't loaded
	err := builder.Load("targets/a/b", meta["targets/a/b"], 1, false)
	require.Error(t, err)
	require.IsType(t, data.ErrInvalidRole{}, err)

	// targets/a can be loaded now though because targets is loaded
	require.NoError(t, builder.Load("targets/a", meta["targets/a"], 1, false))

	// and now targets/a/b can be loaded because targets/a is loaded
	require.NoError(t, builder.Load("targets/a/b", meta["targets/a/b"], 1, false))
}

// We load only if the rolename is a valid rolename - even if the metadata we provided is valid
func TestBuilderLoadsValidRolesOnly(t *testing.T) {
	meta, gun := getSampleMeta(t)
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	err := builder.Load("NotRoot", meta[data.CanonicalRootRole], 1, false)
	require.Error(t, err)
	require.IsType(t, tuf.ErrInvalidBuilderInput{}, err)
	require.Contains(t, err.Error(), "is an invalid role")
}

func TestMarkingIsValid(t *testing.T) {
	meta, gun := getSampleMeta(t)
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})

	// testing that the signed objects have a false isValid value confirming
	// that verify signatures has not been called on them yet
	// now when we check that isValid is true after calling load which calls
	// verify signatures- we can be sure that verify signatures is actually
	// setting the isValid fields for our data.Signed objects
	for _, meta := range meta {
		signedObj := &data.Signed{}
		if err := json.Unmarshal(meta, signedObj); err != nil {
			require.NoError(t, err)
		}
		require.Len(t, signedObj.Signatures, 1)
		require.False(t, signedObj.Signatures[0].IsValid)
	}

	// load the root
	require.NoError(t, builder.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 1, false))

	// load a timestamp
	require.NoError(t, builder.Load(data.CanonicalTimestampRole, meta[data.CanonicalTimestampRole], 1, false))

	// load a snapshot
	require.NoError(t, builder.Load(data.CanonicalSnapshotRole, meta[data.CanonicalSnapshotRole], 1, false))

	// load the targets
	require.NoError(t, builder.Load(data.CanonicalTargetsRole, meta[data.CanonicalTargetsRole], 1, false))

	// targets/a can be loaded now though because targets is loaded
	require.NoError(t, builder.Load("targets/a", meta["targets/a"], 1, false))

	// and now targets/a/b can be loaded because targets/a is loaded
	require.NoError(t, builder.Load("targets/a/b", meta["targets/a/b"], 1, false))

	valid, _, err := builder.Finish()
	// TODO: Once ValidateRoot is changes to set IsValid as per PR #800 we should uncomment the below test to make
	// sure that IsValid is being set on loadRoot
	//require.True(t, valid.Root.Signatures[0].IsValid)
	require.True(t, valid.Timestamp.Signatures[0].IsValid)
	require.True(t, valid.Snapshot.Signatures[0].IsValid)
	require.True(t, valid.Targets[data.CanonicalTargetsRole].Signatures[0].IsValid)
	require.True(t, valid.Targets["targets/a"].Signatures[0].IsValid)
	require.True(t, valid.Targets["targets/a/b"].Signatures[0].IsValid)
	require.NoError(t, err)
}

func TestBuilderStopsAcceptingOrProducingDataOnceDone(t *testing.T) {
	meta, gun := getSampleMeta(t)
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})

	for _, roleName := range data.BaseRoles {
		require.NoError(t, builder.Load(roleName, meta[roleName], 1, false))
		require.True(t, builder.IsLoaded(roleName))
	}

	_, err := builder.Finish()
	require.NoError(t, err)

	err = builder.Load("targets/a", meta["targets/a"], 1, false)
	require.Error(t, err)
	require.Equal(t, tuf.ErrBuildDone, err)

	// a new bootstrapped builder can also not have any more input output
	bootstrapped := builder.BootstrapNewBuilder()

	err = bootstrapped.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 0, false)
	require.Error(t, err)
	require.Equal(t, tuf.ErrBuildDone, err)

	for _, b := range []tuf.RepoBuilder{builder, bootstrapped} {
		_, err = b.Finish()
		require.Error(t, err)
		require.Equal(t, tuf.ErrBuildDone, err)

		_, _, err = b.GenerateSnapshot(nil)
		require.Error(t, err)
		require.Equal(t, tuf.ErrBuildDone, err)

		_, _, err = b.GenerateTimestamp(nil)
		require.Error(t, err)
		require.Equal(t, tuf.ErrBuildDone, err)

		for roleName := range meta {
			// a finished builder thinks nothing is loaded
			require.False(t, b.IsLoaded(roleName))
			// checksums are all empty, versions are all zero
			require.Equal(t, 0, b.GetLoadedVersion(roleName))
			require.Equal(t, tuf.ConsistentInfo{RoleName: roleName}, b.GetConsistentInfo(roleName))
		}

	}
}

func TestBuilderOnlyAcceptsRootFirstWhenLoading(t *testing.T) {
	meta, gun := getSampleMeta(t)
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})

	for roleName, content := range meta {
		if roleName != data.CanonicalRootRole {
			err := builder.Load(roleName, content, 1, true)
			require.Error(t, err)
			require.IsType(t, tuf.ErrInvalidBuilderInput{}, err)
			require.Contains(t, err.Error(), "root must be loaded first")
			require.False(t, builder.IsLoaded(roleName))
			require.Equal(t, 1, builder.GetLoadedVersion(roleName))
		}
	}

	// we can load the root
	require.NoError(t, builder.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 1, false))
	require.True(t, builder.IsLoaded(data.CanonicalRootRole))
}

// If the parent is not in the store, then the parent must be in the update else
// validation fails.
func TestValidateTargetsParentInUpdate(t *testing.T) {
	gun := "docker.com/notary"
	delgName := "targets/level1"
	metadata, _, err := testutils.NewRepoMetadata(gun, delgName, path.Join(delgName, "other"))
	require.NoError(t, err)
	store := storage.NewMemStorage()

	// load the root into the builder, else we can't load anything else
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	require.NoError(t, builder.Load(data.CanonicalRootRole, metadata[data.CanonicalRootRole], 0, false))

	targetsUpdate := storage.MetaUpdate{
		Role:    data.CanonicalTargetsRole,
		Version: 1,
		Data:    []byte("Invalid metadata"),
	}

	delgUpdate := storage.MetaUpdate{
		Role:    delgName,
		Version: 1,
		Data:    metadata[delgName],
	}

	upload := map[string]storage.MetaUpdate{
		"targets/level1":          delgUpdate,
		data.CanonicalTargetsRole: targetsUpdate,
	}

	// parent update not readable - fail
	_, err = loadAndValidateTargets(gun, builder, upload, store)
	require.Error(t, err)
	require.IsType(t, validation.ErrBadTargets{}, err)

	// because we sort the roles, the list of returned updates
	// will contain shallower roles first, in this case "targets",
	// and then "targets/level1"
	targetsUpdate.Data = metadata[data.CanonicalTargetsRole]
	upload[data.CanonicalTargetsRole] = targetsUpdate
	updates, err := loadAndValidateTargets(gun, builder, upload, store)
	require.NoError(t, err)
	require.Equal(t, []storage.MetaUpdate{targetsUpdate, delgUpdate}, updates)
}

func TestBuilderAcceptRoleOnce(t *testing.T) {
	meta, gun := getSampleMeta(t)
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})

	for _, roleName := range append(data.BaseRoles, "targets/a", "targets/a/b") {
		// first time loading is ok
		require.NoError(t, builder.Load(roleName, meta[roleName], 1, false))
		require.True(t, builder.IsLoaded(roleName))
		require.Equal(t, 1, builder.GetLoadedVersion(roleName))

		// second time loading is not
		err := builder.Load(roleName, meta[roleName], 1, false)
		require.Error(t, err)
		require.IsType(t, tuf.ErrInvalidBuilderInput{}, err)
		require.Contains(t, err.Error(), "has already been loaded")

		// still loaded
		require.True(t, builder.IsLoaded(roleName))
	}
}

func TestGenerateSnapshotNoKey(t *testing.T) {
	gun := "docker.com/notary"
	metadata, cs, err := testutils.NewRepoMetadata(gun)
	require.NoError(t, err)
	store := storage.NewMemStorage()

	// delete snapshot key in the cryptoservice
	for _, keyID := range cs.ListKeys(data.CanonicalSnapshotRole) {
		require.NoError(t, cs.RemoveKey(keyID))
	}

	builder := tuf.NewRepoBuilder(gun, cs, trustpinning.TrustPinConfig{})
	// only load root and targets
	require.NoError(t, builder.Load(data.CanonicalRootRole, metadata[data.CanonicalRootRole], 0, false))
	require.NoError(t, builder.Load(data.CanonicalTargetsRole, metadata[data.CanonicalTargetsRole], 0, false))

	_, err = generateSnapshot(gun, builder, store)
	require.Error(t, err)
	require.IsType(t, validation.ErrBadHierarchy{}, err)
}

// ### Target validation with delegations tests
func TestLoadTargetsLoadsNothingIfNoUpdates(t *testing.T) {
	gun := "docker.com/notary"
	metadata, _, err := testutils.NewRepoMetadata(gun)
	require.NoError(t, err)

	// load the root into the builder, else we can't load anything else
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	require.NoError(t, builder.Load(data.CanonicalRootRole, metadata[data.CanonicalRootRole], 0, false))

	store := storage.NewMemStorage()
	store.UpdateCurrent(gun, storage.MetaUpdate{
		Role:    data.CanonicalTargetsRole,
		Version: 1,
		Data:    metadata[data.CanonicalTargetsRole],
	})

	// if no updates, nothing is loaded
	targetsToUpdate, err := loadAndValidateTargets(gun, builder, nil, store)
	require.Empty(t, targetsToUpdate)
	require.NoError(t, err)
	require.False(t, builder.IsLoaded(data.CanonicalTargetsRole))
}

// GetOrCreateSnapshot either returns the existing latest snapshot, or uses
// whatever the most recent snapshot is to generate the next one, only updating
// the expiry time and version.  Note that this function does not write generated
// snapshots to the underlying data store, and will either return the latest snapshot time
// or nil as the time modified
func GetOrCreateSnapshot(gun, checksum string, store storage.MetaStore, cryptoService signed.CryptoService) (
	*time.Time, []byte, error) {

	lastModified, currentJSON, err := store.GetChecksum(gun, data.CanonicalSnapshotRole, checksum)
	if err != nil {
		return nil, nil, err
	}

	prev := new(data.SignedSnapshot)
	if err := json.Unmarshal(currentJSON, prev); err != nil {
		logrus.Error("Failed to unmarshal existing snapshot for GUN ", gun)
		return nil, nil, err
	}

	if !snapshotExpired(prev) {
		return lastModified, currentJSON, nil
	}

	builder := tuf.NewRepoBuilder(gun, cryptoService, trustpinning.TrustPinConfig{})

	// load the current root to ensure we use the correct snapshot key.
	_, rootJSON, err := store.GetCurrent(gun, data.CanonicalRootRole)
	if err != nil {
		logrus.Debug("Previous snapshot, but no root for GUN ", gun)
		return nil, nil, err
	}
	if err := builder.Load(data.CanonicalRootRole, rootJSON, 1, false); err != nil {
		logrus.Debug("Could not load valid previous root for GUN ", gun)
		return nil, nil, err
	}

	meta, _, err := builder.GenerateSnapshot(prev)
	if err != nil {
		return nil, nil, err
	}

	return nil, meta, nil
}

// When a delegation role appears in the update and the parent does not, the
// parent is loaded from the DB if it can
func TestValidateTargetsRequiresStoredParent(t *testing.T) {
	gun := "docker.com/notary"
	delgName := "targets/level1"
	metadata, _, err := testutils.NewRepoMetadata(gun, delgName, path.Join(delgName, "other"))
	require.NoError(t, err)

	// load the root into the builder, else we can't load anything else
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	require.NoError(t, builder.Load(data.CanonicalRootRole, metadata[data.CanonicalRootRole], 0, false))

	delUpdate := storage.MetaUpdate{
		Role:    delgName,
		Version: 1,
		Data:    metadata[delgName],
	}

	upload := map[string]storage.MetaUpdate{delgName: delUpdate}

	store := storage.NewMemStorage()

	// if the DB has no "targets" role
	_, err = loadAndValidateTargets(gun, builder, upload, store)
	require.Error(t, err)
	require.IsType(t, validation.ErrBadTargets{}, err)

	// ensure the "targets" (the parent) is in the "db"
	store.UpdateCurrent(gun, storage.MetaUpdate{
		Role:    data.CanonicalTargetsRole,
		Version: 1,
		Data:    metadata[data.CanonicalTargetsRole],
	})

	updates, err := loadAndValidateTargets(gun, builder, upload, store)
	require.NoError(t, err)
	require.Len(t, updates, 1)
	require.Equal(t, delgName, updates[0].Role)
	require.Equal(t, metadata[delgName], updates[0].Data)
}

// bootstrapClient attempts to bootstrap a root.json to be used as the trust
// anchor for a repository. The checkInitialized argument indicates whether
// we should always attempt to contact the server to determine if the repository
// is initialized or not. If set to true, we will always attempt to download
// and return an error if the remote repository errors.
//
// Populates a tuf.RepoBuilder with this root metadata (only use
// tufclient.Client.Update to load the rest).
//
// Fails if the remote server is reachable and does not know the repo
// (i.e. before the first r.Publish()), in which case the error is
// store.ErrMetaNotFound, or if the root metadata (from whichever source is used)
// is not trusted.
//
// Returns a tufclient.Client for the remote server, which may not be actually
// operational (if the URL is invalid but a root.json is cached).
func (r *NotaryRepository) bootstrapClient(checkInitialized bool) (*tufclient.Client, error) {
	minVersion := 1
	// the old root on disk should not be validated against any trust pinning configuration
	// because if we have an old root, it itself is the thing that pins trust
	oldBuilder := tuf.NewRepoBuilder(r.gun, r.CryptoService, trustpinning.TrustPinConfig{})

	// by default, we want to use the trust pinning configuration on any new root that we download
	newBuilder := tuf.NewRepoBuilder(r.gun, r.CryptoService, r.trustPinning)

	// Try to read root from cache first. We will trust this root until we detect a problem
	// during update which will cause us to download a new root and perform a rotation.
	// If we have an old root, and it's valid, then we overwrite the newBuilder to be one
	// preloaded with the old root or one which uses the old root for trust bootstrapping.
	if rootJSON, err := r.fileStore.GetMeta(data.CanonicalRootRole, store.NoSizeLimit); err == nil {
		// if we can't load the cached root, fail hard because that is how we pin trust
		if err := oldBuilder.Load(data.CanonicalRootRole, rootJSON, minVersion, true); err != nil {
			return nil, err
		}

		// again, the root on disk is the source of trust pinning, so use an empty trust
		// pinning configuration
		newBuilder = tuf.NewRepoBuilder(r.gun, r.CryptoService, trustpinning.TrustPinConfig{})

		if err := newBuilder.Load(data.CanonicalRootRole, rootJSON, minVersion, false); err != nil {
			// Ok, the old root is expired - we want to download a new one.  But we want to use the
			// old root to verify the new root, so bootstrap a new builder with the old builder
			minVersion = oldBuilder.GetLoadedVersion(data.CanonicalRootRole)
			newBuilder = oldBuilder.BootstrapNewBuilder()
		}
	}

	remote, remoteErr := getRemoteStore(r.baseURL, r.gun, r.roundTrip)
	if remoteErr != nil {
		logrus.Error(remoteErr)
	} else if !newBuilder.IsLoaded(data.CanonicalRootRole) || checkInitialized {
		// remoteErr was nil and we were not able to load a root from cache or
		// are specifically checking for initialization of the repo.

		// if remote store successfully set up, try and get root from remote
		// We don't have any local data to determine the size of root, so try the maximum (though it is restricted at 100MB)
		tmpJSON, err := remote.GetMeta(data.CanonicalRootRole, store.NoSizeLimit)
		if err != nil {
			// we didn't have a root in cache and were unable to load one from
			// the server. Nothing we can do but error.
			return nil, err
		}

		if !newBuilder.IsLoaded(data.CanonicalRootRole) {
			// we always want to use the downloaded root if we couldn't load from cache
			if err := newBuilder.Load(data.CanonicalRootRole, tmpJSON, minVersion, false); err != nil {
				return nil, err
			}

			err = r.fileStore.SetMeta(data.CanonicalRootRole, tmpJSON)
			if err != nil {
				// if we can't write cache we should still continue, just log error
				logrus.Errorf("could not save root to cache: %s", err.Error())
			}
		}
	}

	// We can only get here if remoteErr != nil (hence we don't download any new root),
	// and there was no root on disk
	if !newBuilder.IsLoaded(data.CanonicalRootRole) {
		return nil, ErrRepoNotInitialized{}
	}

	return tufclient.NewClient(oldBuilder, newBuilder, remote, r.fileStore), nil
}

// validateUpload checks that the updates being pushed
// are semantically correct and the signatures are correct
// A list of possibly modified updates are returned if all
// validation was successful. This allows the snapshot to be
// created and added if snapshotting has been delegated to the
// server
func validateUpdate(cs signed.CryptoService, gun string, updates []storage.MetaUpdate, store storage.MetaStore) ([]storage.MetaUpdate, error) {

	// some delegated targets role may be invalid based on other updates
	// that have been made by other clients. We'll rebuild the slice of
	// updates with only the things we should actually update
	updatesToApply := make([]storage.MetaUpdate, 0, len(updates))

	roles := make(map[string]storage.MetaUpdate)
	for _, v := range updates {
		roles[v.Role] = v
	}

	builder := tuf.NewRepoBuilder(gun, cs, trustpinning.TrustPinConfig{})
	if err := loadFromStore(gun, data.CanonicalRootRole, builder, store); err != nil {
		if _, ok := err.(storage.ErrNotFound); !ok {
			return nil, err
		}
	}

	if rootUpdate, ok := roles[data.CanonicalRootRole]; ok {
		builder = builder.BootstrapNewBuilder()
		if err := builder.Load(data.CanonicalRootRole, rootUpdate.Data, 1, false); err != nil {
			return nil, validation.ErrBadRoot{Msg: err.Error()}
		}

		logrus.Debug("Successfully validated root")
		updatesToApply = append(updatesToApply, rootUpdate)
	} else if !builder.IsLoaded(data.CanonicalRootRole) {
		return nil, validation.ErrValidation{Msg: "no pre-existing root and no root provided in update."}
	}

	targetsToUpdate, err := loadAndValidateTargets(gun, builder, roles, store)
	if err != nil {
		return nil, err
	}
	updatesToApply = append(updatesToApply, targetsToUpdate...)
	// there's no need to load files from the database if no targets etc...
	// were uploaded because that means they haven't been updated and
	// the snapshot will already contain the correct hashes and sizes for
	// those targets (incl. delegated targets)
	logrus.Debug("Successfully validated targets")

	// At this point, root and targets must have been loaded into the repo
	if snapshotUpdate, ok := roles[data.CanonicalSnapshotRole]; ok {
		if err := builder.Load(data.CanonicalSnapshotRole, snapshotUpdate.Data, 1, false); err != nil {
			return nil, validation.ErrBadSnapshot{Msg: err.Error()}
		}
		logrus.Debug("Successfully validated snapshot")
		updatesToApply = append(updatesToApply, roles[data.CanonicalSnapshotRole])
	} else {
		// Check:
		//   - we have a snapshot key
		//   - it matches a snapshot key signed into the root.json
		// Then:
		//   - generate a new snapshot
		//   - add it to the updates
		update, err := generateSnapshot(gun, builder, store)
		if err != nil {
			return nil, err
		}
		updatesToApply = append(updatesToApply, *update)
	}

	// generate a timestamp immediately
	update, err := generateTimestamp(gun, builder, store)
	if err != nil {
		return nil, err
	}
	return append(updatesToApply, *update), nil
}

// If the parent, either from the DB or from an update, does not contain the role
// of the delegation update, validation fails
func TestValidateTargetsRoleNotInParent(t *testing.T) {
	// no delegation at first
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)

	meta, err := testutils.SignAndSerialize(repo)
	require.NoError(t, err)

	// load the root into the builder, else we can't load anything else
	builder := tuf.NewRepoBuilder(gun, nil, trustpinning.TrustPinConfig{})
	require.NoError(t, builder.Load(data.CanonicalRootRole, meta[data.CanonicalRootRole], 0, false))

	// prepare the original targets file, without a delegation role, as an update
	origTargetsUpdate := storage.MetaUpdate{
		Role:    data.CanonicalTargetsRole,
		Version: 1,
		Data:    meta[data.CanonicalTargetsRole],
	}
	emptyStore := storage.NewMemStorage()
	storeWithParent := storage.NewMemStorage()
	storeWithParent.UpdateCurrent(gun, origTargetsUpdate)

	// add a delegation role now
	delgName := "targets/level1"
	level1Key, err := testutils.CreateKey(cs, gun, delgName, data.ECDSAKey)
	require.NoError(t, err)
	require.NoError(t, repo.UpdateDelegationKeys(delgName, []data.PublicKey{level1Key}, []string{}, 1))
	// create the delegation metadata too
	repo.InitTargets(delgName)

	// re-serialize
	meta, err = testutils.SignAndSerialize(repo)
	require.NoError(t, err)
	delgMeta, ok := meta[delgName]
	require.True(t, ok)

	delgUpdate := storage.MetaUpdate{
		Role:    delgName,
		Version: 1,
		Data:    delgMeta,
	}

	// parent in update does not have this role, whether or not there's a parent in the store,
	// so validation fails
	roles := map[string]storage.MetaUpdate{
		delgName:                  delgUpdate,
		data.CanonicalTargetsRole: origTargetsUpdate,
	}
	for _, metaStore := range []storage.MetaStore{emptyStore, storeWithParent} {
		updates, err := loadAndValidateTargets(gun, builder, roles, metaStore)
		require.Error(t, err)
		require.Empty(t, updates)
		require.IsType(t, validation.ErrBadTargets{}, err)
	}

	// if the update is provided without the parent, then the parent from the
	// store is loaded - if it doesn't have the role, then the update fails
	updates, err := loadAndValidateTargets(gun, builder,
		map[string]storage.MetaUpdate{delgName: delgUpdate}, storeWithParent)
	require.Error(t, err)
	require.Empty(t, updates)
	require.IsType(t, validation.ErrBadTargets{}, err)
}