Fixes + stable gateway ids

2026-02-18 20:38:08 +01:00
parent 4dc182bfa2
commit 770c7b9da9
119 changed files with 3000 additions and 734 deletions
--- a/api/billing/documents/.golangci.yml
+++ b/api/billing/documents/.golangci.yml
@@ -0,0 +1,195 @@
+# See the dedicated "version" documentation section.
+version: "2"
+linters:
+  # Default set of linters.
+  # The value can be:
+  # - `standard`: https://golangci-lint.run/docs/linters/#enabled-by-default
+  # - `all`: enables all linters by default.
+  # - `none`: disables all linters by default.
+  # - `fast`: enables only linters considered as "fast" (`golangci-lint help linters --json | jq '[ .[] | select(.fast==true) ] | map(.name)'`).
+  # Default: standard
+  default: all
+  # Enable specific linter.
+  enable:
+    - arangolint
+    - asasalint
+    - asciicheck
+    - bidichk
+    - bodyclose
+    - canonicalheader
+    - containedctx
+    - contextcheck
+    - copyloopvar
+    - cyclop
+    - decorder
+    - dogsled
+    - dupl
+    - dupword
+    - durationcheck
+    - embeddedstructfieldcheck
+    - err113
+    - errcheck
+    - errchkjson
+    - errname
+    - errorlint
+    - exhaustive
+    - exptostd
+    - fatcontext
+    - forbidigo
+    - forcetypeassert
+    - funcorder
+    - funlen
+    - ginkgolinter
+    - gocheckcompilerdirectives
+    - gochecknoglobals
+    - gochecknoinits
+    - gochecksumtype
+    - gocognit
+    - goconst
+    - gocritic
+    - gocyclo
+    - godoclint
+    - godot
+    - godox
+    - goheader
+    - gomodguard
+    - goprintffuncname
+    - gosec
+    - gosmopolitan
+    - govet
+    - grouper
+    - iface
+    - importas
+    - inamedparam
+    - ineffassign
+    - interfacebloat
+    - intrange
+    - iotamixing
+    - ireturn
+    - lll
+    - loggercheck
+    - maintidx
+    - makezero
+    - mirror
+    - misspell
+    - mnd
+    - modernize
+    - musttag
+    - nakedret
+    - nestif
+    - nilerr
+    - nilnesserr
+    - nilnil
+    - nlreturn
+    - noctx
+    - noinlineerr
+    - nolintlint
+    - nonamedreturns
+    - nosprintfhostport
+    - paralleltest
+    - perfsprint
+    - prealloc
+    - predeclared
+    - promlinter
+    - protogetter
+    - reassign
+    - recvcheck
+    - revive
+    - rowserrcheck
+    - sloglint
+    - spancheck
+    - sqlclosecheck
+    - staticcheck
+    - tagalign
+    - tagliatelle
+    - testableexamples
+    - testifylint
+    - testpackage
+    - thelper
+    - tparallel
+    - unconvert
+    - unparam
+    - unqueryvet
+    - unused
+    - usestdlibvars
+    - usetesting
+    - varnamelen
+    - wastedassign
+    - whitespace
+    - wsl_v5
+    - zerologlint
+  # Disable specific linters.
+  disable: 
+    - depguard
+    - exhaustruct
+    - gochecknoglobals
+    - gomoddirectives
+    - wsl
+    - wrapcheck
+  # All available settings of specific linters.
+  # See the dedicated "linters.settings" documentation section.
+  settings:
+    wsl_v5:
+      allow-first-in-block: true
+      allow-whole-block: false
+      branch-max-lines: 2 
+
+  # Defines a set of rules to ignore issues.
+  # It does not skip the analysis, and so does not ignore "typecheck" errors.
+  exclusions:
+    # Mode of the generated files analysis.
+    #
+    # - `strict`: sources are excluded by strictly following the Go generated file convention.
+    #    Source files that have lines matching only the following regular expression will be excluded: `^// Code generated .* DO NOT EDIT\.$`
+    #    This line must appear before the first non-comment, non-blank text in the file.
+    #    https://go.dev/s/generatedcode
+    # - `lax`: sources are excluded if they contain lines like `autogenerated file`, `code generated`, `do not edit`, etc.
+    # - `disable`: disable the generated files exclusion.
+    #
+    # Default: strict
+    generated: lax
+    # Log a warning if an exclusion rule is unused.
+    # Default: false
+    warn-unused: true
+    # Predefined exclusion rules.
+    # Default: []
+    presets:
+      - comments
+      - std-error-handling
+      - common-false-positives
+      - legacy
+    # Excluding configuration per-path, per-linter, per-text and per-source.
+    rules:
+      # Exclude some linters from running on tests files.
+      - path: _test\.go
+        linters:
+          - gocyclo
+          - errcheck
+          - dupl
+          - gosec
+      # Run some linter only for test files by excluding its issues for everything else.
+      - path-except: _test\.go
+        linters:
+          - forbidigo
+      # Exclude known linters from partially hard-vendored code,
+      # which is impossible to exclude via `nolint` comments.
+      # `/` will be replaced by the current OS file path separator to properly work on Windows.
+      - path: internal/hmac/
+        text: "weak cryptographic primitive"
+        linters:
+          - gosec
+      # Exclude some `staticcheck` messages.
+      - linters:
+          - staticcheck
+        text: "SA9003:"
+      # Exclude `lll` issues for long lines with `go:generate`.
+      - linters:
+          - lll
+        source: "^//go:generate "
+    # Which file paths to exclude: they will be analyzed, but issues from them won't be reported.
+    # "/" will be replaced by the current OS file path separator to properly work on Windows.
+    # Default: []
+    paths: []
+    # Which file paths to not exclude.
+    # Default: []
+    paths-except: []
--- a/api/billing/documents/internal/appversion/version.go
+++ b/api/billing/documents/internal/appversion/version.go
@@ -24,5 +24,6 @@ func Create() version.Printer {
 		BuildDate: BuildDate,
 		Version:   Version,
 	}
+
 	return vf.Create(&info)
 }
--- a/api/billing/documents/internal/docstore/local.go
+++ b/api/billing/documents/internal/docstore/local.go
@@ -21,11 +21,13 @@ func NewLocalStore(logger mlogger.Logger, cfg LocalConfig) (*LocalStore, error)
 	if root == "" {
 		return nil, merrors.InvalidArgument("docstore: local root_path is empty")
 	}
+
 	store := &LocalStore{
 		logger:   logger.Named("docstore").Named("local"),
 		rootPath: root,
 	}
 	store.logger.Info("Document storage initialised", zap.String("root_path", root))
+
 	return store, nil
 }

@@ -33,15 +35,19 @@ func (s *LocalStore) Save(ctx context.Context, key string, data []byte) error {
 	if err := ctx.Err(); err != nil {
 		return err
 	}
+
 	path := filepath.Join(s.rootPath, filepath.Clean(key))
 	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
 		s.logger.Warn("Failed to create document directory", zap.Error(err), zap.String("path", path))
+
 		return err
 	}
 	if err := os.WriteFile(path, data, 0o600); err != nil {
 		s.logger.Warn("Failed to write document file", zap.Error(err), zap.String("path", path))
+
 		return err
 	}
+
 	return nil
 }

@@ -49,12 +55,16 @@ func (s *LocalStore) Load(ctx context.Context, key string) ([]byte, error) {
 	if err := ctx.Err(); err != nil {
 		return nil, err
 	}
+
 	path := filepath.Join(s.rootPath, filepath.Clean(key))
+
 	data, err := os.ReadFile(path)
 	if err != nil {
 		s.logger.Warn("Failed to read document file", zap.Error(err), zap.String("path", path))
+
 		return nil, err
 	}
+
 	return data, nil
 }

--- a/api/billing/documents/internal/docstore/s3.go
+++ b/api/billing/documents/internal/docstore/s3.go
@@ -32,6 +32,7 @@ func NewS3Store(logger mlogger.Logger, cfg S3Config) (*S3Store, error) {
 	if accessKey == "" && cfg.AccessKeyEnv != "" {
 		accessKey = strings.TrimSpace(os.Getenv(cfg.AccessKeyEnv))
 	}
+
 	secretKey := strings.TrimSpace(cfg.SecretAccessKey)
 	if secretKey == "" && cfg.SecretKeyEnv != "" {
 		secretKey = strings.TrimSpace(os.Getenv(cfg.SecretKeyEnv))
@@ -62,23 +63,21 @@ func NewS3Store(logger mlogger.Logger, cfg S3Config) (*S3Store, error) {
 				endpoint = "http://" + endpoint
 			}
 		}
-		resolver := aws.EndpointResolverWithOptionsFunc(func(service, region string, _ ...interface{}) (aws.Endpoint, error) {
-			if service == s3.ServiceID {
-				return aws.Endpoint{URL: endpoint, SigningRegion: region, HostnameImmutable: true}, nil
-			}
-			return aws.Endpoint{}, &aws.EndpointNotFoundError{}
-		})
-		loadOpts = append(loadOpts, config.WithEndpointResolverWithOptions(resolver))
 	}

 	awsCfg, err := config.LoadDefaultConfig(context.Background(), loadOpts...)
 	if err != nil {
 		logger.Warn("Failed to create AWS config", zap.Error(err), zap.String("bucket", bucket))
+
 		return nil, err
 	}

 	client := s3.NewFromConfig(awsCfg, func(opts *s3.Options) {
 		opts.UsePathStyle = cfg.ForcePathStyle
+
+		if endpoint != "" {
+			opts.BaseEndpoint = aws.String(endpoint)
+		}
 	})

 	store := &S3Store{
@@ -87,6 +86,7 @@ func NewS3Store(logger mlogger.Logger, cfg S3Config) (*S3Store, error) {
 		bucket: bucket,
 	}
 	store.logger.Info("Document storage initialised", zap.String("bucket", bucket), zap.String("endpoint", endpoint))
+
 	return store, nil
 }

@@ -94,6 +94,7 @@ func (s *S3Store) Save(ctx context.Context, key string, data []byte) error {
 	if err := ctx.Err(); err != nil {
 		return err
 	}
+
 	_, err := s.client.PutObject(ctx, &s3.PutObjectInput{
 		Bucket: aws.String(s.bucket),
 		Key:    aws.String(key),
@@ -101,8 +102,10 @@ func (s *S3Store) Save(ctx context.Context, key string, data []byte) error {
 	})
 	if err != nil {
 		s.logger.Warn("Failed to upload document", zap.Error(err), zap.String("key", key))
+
 		return err
 	}
+
 	return nil
 }

@@ -110,15 +113,19 @@ func (s *S3Store) Load(ctx context.Context, key string) ([]byte, error) {
 	if err := ctx.Err(); err != nil {
 		return nil, err
 	}
+
 	obj, err := s.client.GetObject(ctx, &s3.GetObjectInput{
 		Bucket: aws.String(s.bucket),
 		Key:    aws.String(key),
 	})
 	if err != nil {
 		s.logger.Warn("Failed to fetch document", zap.Error(err), zap.String("key", key))
+
 		return nil, err
 	}
+
 	defer obj.Body.Close()
+
 	return io.ReadAll(obj.Body)
 }

--- a/api/billing/documents/internal/docstore/store.go
+++ b/api/billing/documents/internal/docstore/store.go
@@ -36,7 +36,7 @@ type S3Config struct {
 	Bucket          string `yaml:"bucket"`
 	AccessKeyEnv    string `yaml:"access_key_env"`
 	SecretKeyEnv    string `yaml:"secret_access_key_env"`
-	AccessKey       string `yaml:"access_key"`
+	AccessKey       string `yaml:"access_key"` //nolint:gosec // config field, not a hardcoded secret
 	SecretAccessKey string `yaml:"secret_access_key"`
 	UseSSL          bool   `yaml:"use_ssl"`
 	ForcePathStyle  bool   `yaml:"force_path_style"`
@@ -55,11 +55,13 @@ func New(logger mlogger.Logger, cfg Config) (Store, error) {
 		if cfg.Local == nil {
 			return nil, merrors.InvalidArgument("docstore: local config missing")
 		}
+
 		return NewLocalStore(logger, *cfg.Local)
 	case string(DriverS3), string(DriverMinio):
 		if cfg.S3 == nil {
 			return nil, merrors.InvalidArgument("docstore: s3 config missing")
 		}
+
 		return NewS3Store(logger, *cfg.S3)
 	default:
 		return nil, merrors.InvalidArgument("docstore: unsupported driver")
--- a/api/billing/documents/internal/server/internal/serverimp.go
+++ b/api/billing/documents/internal/server/internal/serverimp.go
@@ -29,7 +29,8 @@ type Imp struct {

 type config struct {
 	*grpcapp.Config `yaml:",inline"`
-	Documents       documents.Config `yaml:"documents"`
+
+	Documents documents.Config `yaml:"documents"`
 }

 // Create initialises the billing documents server implementation.
@@ -46,6 +47,7 @@ func (i *Imp) Shutdown() {
 		if i.service != nil {
 			i.service.Shutdown()
 		}
+
 		return
 	}

@@ -68,6 +70,7 @@ func (i *Imp) Start() error {
 	if err != nil {
 		return err
 	}
+
 	i.config = cfg

 	repoFactory := func(logger mlogger.Logger, conn *db.MongoConnection) (storage.Repository, error) {
@@ -77,20 +80,23 @@ func (i *Imp) Start() error {
 	docStore, err := docstore.New(i.logger, cfg.Documents.Storage)
 	if err != nil {
 		i.logger.Error("Failed to initialise document storage", zap.Error(err))
+
 		return err
 	}

-	serviceFactory := func(logger mlogger.Logger, repo storage.Repository, producer msg.Producer) (grpcapp.Service, error) {
+	serviceFactory := func(logger mlogger.Logger, repo storage.Repository, producer msg.Producer) (grpcapp.Service, error) { //nolint:lll // factory signature dictated by grpcapp
 		invokeURI := ""
 		if cfg.GRPC != nil {
 			invokeURI = cfg.GRPC.DiscoveryInvokeURI()
 		}
+
 		svc := documents.NewService(logger, repo, producer,
 			documents.WithDiscoveryInvokeURI(invokeURI),
 			documents.WithConfig(cfg.Documents),
 			documents.WithDocumentStore(docStore),
 		)
 		i.service = svc
+
 		return svc, nil
 	}

@@ -98,6 +104,7 @@ func (i *Imp) Start() error {
 	if err != nil {
 		return err
 	}
+
 	i.app = app

 	return i.app.Start()
@@ -107,12 +114,14 @@ func (i *Imp) loadConfig() (*config, error) {
 	data, err := os.ReadFile(i.file)
 	if err != nil {
 		i.logger.Error("Could not read configuration file", zap.String("config_file", i.file), zap.Error(err))
+
 		return nil, err
 	}

 	cfg := &config{Config: &grpcapp.Config{}}
 	if err := yaml.Unmarshal(data, cfg); err != nil {
 		i.logger.Error("Failed to parse configuration", zap.Error(err))
+
 		return nil, err
 	}

--- a/api/billing/documents/internal/service/documents/config.go
+++ b/api/billing/documents/internal/service/documents/config.go
@@ -29,5 +29,6 @@ func (c Config) AcceptanceTemplatePath() string {
 	if strings.TrimSpace(c.Templates.AcceptancePath) == "" {
 		return "templates/acceptance.tpl"
 	}
+
 	return c.Templates.AcceptancePath
 }
--- a/api/billing/documents/internal/service/documents/metrics.go
+++ b/api/billing/documents/internal/service/documents/metrics.go
@@ -85,14 +85,18 @@ func statusFromError(err error) string {
 	if err == nil {
 		return "success"
 	}
+
 	st, ok := status.FromError(err)
 	if !ok {
 		return "error"
 	}
+
 	code := st.Code()
+
 	if code == codes.OK {
 		return "success"
 	}
+
 	return strings.ToLower(code.String())
 }

@@ -101,5 +105,6 @@ func docTypeLabel(docType documentsv1.DocumentType) string {
 	if label == "" {
 		return "DOCUMENT_TYPE_UNSPECIFIED"
 	}
+
 	return label
 }
--- a/api/billing/documents/internal/service/documents/service.go
+++ b/api/billing/documents/internal/service/documents/service.go
@@ -41,6 +41,7 @@ func WithDiscoveryInvokeURI(uri string) Option {
 		if s == nil {
 			return
 		}
+
 		s.invokeURI = strings.TrimSpace(uri)
 	}
 }
@@ -51,6 +52,7 @@ func WithProducer(producer msg.Producer) Option {
 		if s == nil {
 			return
 		}
+
 		s.producer = producer
 	}
 }
@@ -61,6 +63,7 @@ func WithConfig(cfg Config) Option {
 		if s == nil {
 			return
 		}
+
 		s.config = cfg
 	}
 }
@@ -71,6 +74,7 @@ func WithDocumentStore(store docstore.Store) Option {
 		if s == nil {
 			return
 		}
+
 		s.docStore = store
 	}
 }
@@ -81,12 +85,15 @@ func WithTemplateRenderer(renderer TemplateRenderer) Option {
 		if s == nil {
 			return
 		}
+
 		s.template = renderer
 	}
 }

 // Service provides billing document metadata and retrieval endpoints.
 type Service struct {
+	documentsv1.UnimplementedDocumentServiceServer
+
 	logger    mlogger.Logger
 	storage   storage.Repository
 	docStore  docstore.Store
@@ -95,12 +102,12 @@ type Service struct {
 	invokeURI string
 	config    Config
 	template  TemplateRenderer
-	documentsv1.UnimplementedDocumentServiceServer
 }

 // NewService constructs a documents service with optional configuration.
 func NewService(logger mlogger.Logger, repo storage.Repository, producer msg.Producer, opts ...Option) *Service {
 	initMetrics()
+
 	svc := &Service{
 		logger:   logger.Named("documents"),
 		storage:  repo,
@@ -109,6 +116,7 @@ func NewService(logger mlogger.Logger, repo storage.Repository, producer msg.Pro
 	for _, opt := range opts {
 		opt(svc)
 	}
+
 	if svc.template == nil {
 		if tmpl, err := newTemplateRenderer(svc.config.AcceptanceTemplatePath()); err != nil {
 			svc.logger.Warn("Failed to load acceptance template", zap.Error(err))
@@ -116,7 +124,9 @@ func NewService(logger mlogger.Logger, repo storage.Repository, producer msg.Pro
 			svc.template = tmpl
 		}
 	}
+
 	svc.startDiscoveryAnnouncer()
+
 	return svc
 }

@@ -130,32 +140,22 @@ func (s *Service) Shutdown() {
 	if s == nil {
 		return
 	}
+
 	if s.announcer != nil {
 		s.announcer.Stop()
 	}
 }

-func (s *Service) startDiscoveryAnnouncer() {
-	if s == nil || s.producer == nil {
-		return
-	}
-	announce := discovery.Announcement{
-		Service:    "BILLING_DOCUMENTS",
-		Operations: []string{"documents.batch_resolve", "documents.get"},
-		InvokeURI:  s.invokeURI,
-		Version:    appversion.Create().Short(),
-	}
-	s.announcer = discovery.NewAnnouncer(s.logger, s.producer, string(mservice.BillingDocuments), announce)
-	s.announcer.Start()
-}
-
 func (s *Service) BatchResolveDocuments(ctx context.Context, req *documentsv1.BatchResolveDocumentsRequest) (resp *documentsv1.BatchResolveDocumentsResponse, err error) {
 	start := time.Now()
+
 	var paymentRefs []string
 	if req != nil {
 		paymentRefs = req.GetPaymentRefs()
 	}
+
 	logger := s.logger.With(zap.Int("payment_refs", len(paymentRefs)))
+
 	defer func() {
 		statusLabel := statusFromError(err)
 		observeRequest("batch_resolve", documentsv1.DocumentType_DOCUMENT_TYPE_UNSPECIFIED, statusLabel, time.Since(start))
@@ -165,38 +165,48 @@ func (s *Service) BatchResolveDocuments(ctx context.Context, req *documentsv1.Ba
 		if resp != nil {
 			itemsCount = len(resp.GetItems())
 		}
+
 		fields := []zap.Field{
 			zap.String("status", statusLabel),
 			zap.Duration("duration", time.Since(start)),
 			zap.Int("items", itemsCount),
 		}
+
 		if err != nil {
 			logger.Warn("BatchResolveDocuments failed", append(fields, zap.Error(err))...)
+
 			return
 		}
+
 		logger.Info("BatchResolveDocuments finished", fields...)
 	}()

 	if len(paymentRefs) == 0 {
 		resp = &documentsv1.BatchResolveDocumentsResponse{}
+
 		return resp, nil
 	}

 	if s.storage == nil {
 		err = status.Error(codes.Unavailable, errStorageUnavailable.Error())
+
 		return nil, err
 	}

 	refs := make([]string, 0, len(paymentRefs))
 	for _, ref := range paymentRefs {
 		clean := strings.TrimSpace(ref)
+
 		if clean == "" {
 			continue
 		}
+
 		refs = append(refs, clean)
 	}
+
 	if len(refs) == 0 {
 		resp = &documentsv1.BatchResolveDocumentsResponse{}
+
 		return resp, nil
 	}

@@ -206,10 +216,12 @@ func (s *Service) BatchResolveDocuments(ctx context.Context, req *documentsv1.Ba
 	}

 	recordByRef := map[string]*model.DocumentRecord{}
+
 	for _, record := range records {
 		if record == nil {
 			continue
 		}
+
 		recordByRef[record.PaymentRef] = record
 	}

@@ -218,18 +230,23 @@ func (s *Service) BatchResolveDocuments(ctx context.Context, req *documentsv1.Ba
 		meta := &documentsv1.DocumentMeta{PaymentRef: ref}
 		if record := recordByRef[ref]; record != nil {
 			record.Normalize()
+
 			available := []model.DocumentType{model.DocumentTypeAct}
+
 			ready := make([]model.DocumentType, 0, 1)
 			if path, ok := record.StoragePaths[model.DocumentTypeAct]; ok && path != "" {
 				ready = append(ready, model.DocumentTypeAct)
 			}
+
 			meta.AvailableTypes = toProtoTypes(available)
 			meta.ReadyTypes = toProtoTypes(ready)
 		}
+
 		items = append(items, meta)
 	}

 	resp = &documentsv1.BatchResolveDocumentsResponse{Items: items}
+
 	return resp, nil
 }

@@ -237,10 +254,12 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 	start := time.Now()
 	docType := documentsv1.DocumentType_DOCUMENT_TYPE_UNSPECIFIED
 	paymentRef := ""
+
 	if req != nil {
 		docType = req.GetType()
 		paymentRef = strings.TrimSpace(req.GetPaymentRef())
 	}
+
 	logger := s.logger.With(
 		zap.String("payment_ref", paymentRef),
 		zap.String("document_type", docTypeLabel(docType)),
@@ -249,6 +268,7 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 	defer func() {
 		statusLabel := statusFromError(err)
 		observeRequest("get_document", docType, statusLabel, time.Since(start))
+
 		if resp != nil {
 			observeDocumentBytes(docType, len(resp.GetContent()))
 		}
@@ -257,36 +277,49 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 		if resp != nil {
 			contentBytes = len(resp.GetContent())
 		}
+
 		fields := []zap.Field{
 			zap.String("status", statusLabel),
 			zap.Duration("duration", time.Since(start)),
 			zap.Int("content_bytes", contentBytes),
 		}
+
 		if err != nil {
 			logger.Warn("GetDocument failed", append(fields, zap.Error(err))...)
+
 			return
 		}
+
 		logger.Info("GetDocument finished", fields...)
 	}()

 	if paymentRef == "" {
 		err = status.Error(codes.InvalidArgument, "payment_ref is required")
+
 		return nil, err
 	}
+
 	if docType == documentsv1.DocumentType_DOCUMENT_TYPE_UNSPECIFIED {
 		err = status.Error(codes.InvalidArgument, "document type is required")
+
 		return nil, err
 	}
+
 	if s.storage == nil {
 		err = status.Error(codes.Unavailable, errStorageUnavailable.Error())
+
 		return nil, err
 	}
+
 	if s.docStore == nil {
 		err = status.Error(codes.Unavailable, errDocStoreUnavailable.Error())
+
 		return nil, err
 	}
+
 	if s.template == nil {
 		err = status.Error(codes.FailedPrecondition, errTemplateUnavailable.Error())
+
 		return nil, err
 	}

@@ -295,8 +328,10 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 		if errors.Is(err, storage.ErrDocumentNotFound) {
 			return nil, status.Error(codes.NotFound, "document record not found")
 		}
+
 		return nil, status.Error(codes.Internal, err.Error())
 	}
+
 	record.Normalize()

 	targetType := model.DocumentTypeFromProto(docType)
@@ -310,6 +345,7 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 		if loadErr != nil {
 			return nil, status.Error(codes.Internal, loadErr.Error())
 		}
+
 		return &documentsv1.GetDocumentResponse{
 			Content:  content,
 			Filename: documentFilename(docType, paymentRef),
@@ -320,19 +356,23 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 	content, hash, genErr := s.generateActPDF(record.Snapshot)
 	if genErr != nil {
 		logger.Warn("Failed to generate document", zap.Error(genErr))
+
 		return nil, status.Error(codes.Internal, genErr.Error())
 	}

 	path := documentStoragePath(paymentRef, docType)
 	if saveErr := s.docStore.Save(ctx, path, content); saveErr != nil {
 		logger.Warn("Failed to store document", zap.Error(saveErr))
+
 		return nil, status.Error(codes.Internal, saveErr.Error())
 	}

 	record.StoragePaths[targetType] = path
 	record.Hashes[targetType] = hash
+
 	if updateErr := s.storage.Documents().Update(ctx, record); updateErr != nil {
 		logger.Warn("Failed to update document record", zap.Error(updateErr))
+
 		return nil, status.Error(codes.Internal, updateErr.Error())
 	}

@@ -341,9 +381,25 @@ func (s *Service) GetDocument(ctx context.Context, req *documentsv1.GetDocumentR
 		Filename: documentFilename(docType, paymentRef),
 		MimeType: "application/pdf",
 	}
+
 	return resp, nil
 }

+func (s *Service) startDiscoveryAnnouncer() {
+	if s == nil || s.producer == nil {
+		return
+	}
+
+	announce := discovery.Announcement{
+		Service:    "BILLING_DOCUMENTS",
+		Operations: []string{"documents.batch_resolve", "documents.get"},
+		InvokeURI:  s.invokeURI,
+		Version:    appversion.Create().Short(),
+	}
+	s.announcer = discovery.NewAnnouncer(s.logger, s.producer, mservice.BillingDocuments, announce)
+	s.announcer.Start()
+}
+
 type serviceError string

 func (e serviceError) Error() string {
@@ -361,15 +417,18 @@ func (s *Service) generateActPDF(snapshot model.ActSnapshot) ([]byte, string, er
 	if err != nil {
 		return nil, "", err
 	}
+
 	generated := renderer.Renderer{
 		Issuer:        s.config.Issuer,
 		OwnerPassword: s.config.Protection.OwnerPassword,
 	}
 	placeholder := strings.Repeat("0", 64)
+
 	firstPass, err := generated.Render(blocks, placeholder)
 	if err != nil {
 		return nil, "", err
 	}
+
 	footerHash := sha256.Sum256(firstPass)
 	footerHex := hex.EncodeToString(footerHash[:])

@@ -377,6 +436,7 @@ func (s *Service) generateActPDF(snapshot model.ActSnapshot) ([]byte, string, er
 	if err != nil {
 		return nil, "", err
 	}
+
 	return finalBytes, footerHex, nil
 }

@@ -384,15 +444,18 @@ func toProtoTypes(types []model.DocumentType) []documentsv1.DocumentType {
 	if len(types) == 0 {
 		return nil
 	}
+
 	result := make([]documentsv1.DocumentType, 0, len(types))
 	for _, t := range types {
 		result = append(result, t.Proto())
 	}
+
 	return result
 }

 func documentStoragePath(paymentRef string, docType documentsv1.DocumentType) string {
 	suffix := "document.pdf"
+
 	switch docType {
 	case documentsv1.DocumentType_DOCUMENT_TYPE_ACT:
 		suffix = "act.pdf"
@@ -400,12 +463,16 @@ func documentStoragePath(paymentRef string, docType documentsv1.DocumentType) st
 		suffix = "invoice.pdf"
 	case documentsv1.DocumentType_DOCUMENT_TYPE_RECEIPT:
 		suffix = "receipt.pdf"
+	case documentsv1.DocumentType_DOCUMENT_TYPE_UNSPECIFIED:
+		// default suffix used
 	}
+
 	return filepath.ToSlash(filepath.Join("documents", paymentRef, suffix))
 }

 func documentFilename(docType documentsv1.DocumentType, paymentRef string) string {
 	name := "document"
+
 	switch docType {
 	case documentsv1.DocumentType_DOCUMENT_TYPE_ACT:
 		name = "act"
@@ -413,6 +480,9 @@ func documentFilename(docType documentsv1.DocumentType, paymentRef string) strin
 		name = "invoice"
 	case documentsv1.DocumentType_DOCUMENT_TYPE_RECEIPT:
 		name = "receipt"
+	case documentsv1.DocumentType_DOCUMENT_TYPE_UNSPECIFIED:
+		// default name used
 	}
+
 	return fmt.Sprintf("%s_%s.pdf", name, paymentRef)
 }
--- a/api/billing/documents/internal/service/documents/service_test.go
+++ b/api/billing/documents/internal/service/documents/service_test.go
@@ -18,7 +18,7 @@ type stubRepo struct {
 	store storage.DocumentsStore
 }

-func (s *stubRepo) Ping(ctx context.Context) error    { return nil }
+func (s *stubRepo) Ping(_ context.Context) error      { return nil }
 func (s *stubRepo) Documents() storage.DocumentsStore { return s.store }

 var _ storage.Repository = (*stubRepo)(nil)
@@ -28,22 +28,24 @@ type stubDocumentsStore struct {
 	updateCalls int
 }

-func (s *stubDocumentsStore) Create(ctx context.Context, record *model.DocumentRecord) error {
+func (s *stubDocumentsStore) Create(_ context.Context, record *model.DocumentRecord) error {
 	s.record = record
+
 	return nil
 }

-func (s *stubDocumentsStore) Update(ctx context.Context, record *model.DocumentRecord) error {
+func (s *stubDocumentsStore) Update(_ context.Context, record *model.DocumentRecord) error {
 	s.record = record
 	s.updateCalls++
+
 	return nil
 }

-func (s *stubDocumentsStore) GetByPaymentRef(ctx context.Context, paymentRef string) (*model.DocumentRecord, error) {
+func (s *stubDocumentsStore) GetByPaymentRef(_ context.Context, _ string) (*model.DocumentRecord, error) {
 	return s.record, nil
 }

-func (s *stubDocumentsStore) ListByPaymentRefs(ctx context.Context, paymentRefs []string) ([]*model.DocumentRecord, error) {
+func (s *stubDocumentsStore) ListByPaymentRefs(_ context.Context, _ []string) ([]*model.DocumentRecord, error) {
 	return []*model.DocumentRecord{s.record}, nil
 }

@@ -59,19 +61,21 @@ func newMemDocStore() *memDocStore {
 	return &memDocStore{data: map[string][]byte{}}
 }

-func (m *memDocStore) Save(ctx context.Context, key string, data []byte) error {
+func (m *memDocStore) Save(_ context.Context, key string, data []byte) error {
 	m.saveCount++
 	copyData := make([]byte, len(data))
 	copy(copyData, data)
 	m.data[key] = copyData
+
 	return nil
 }

-func (m *memDocStore) Load(ctx context.Context, key string) ([]byte, error) {
+func (m *memDocStore) Load(_ context.Context, key string) ([]byte, error) {
 	m.loadCount++
 	data := m.data[key]
 	copyData := make([]byte, len(data))
 	copy(copyData, data)
+
 	return copyData, nil
 }

@@ -84,8 +88,9 @@ type stubTemplate struct {
 	calls  int
 }

-func (s *stubTemplate) Render(snapshot model.ActSnapshot) ([]renderer.Block, error) {
+func (s *stubTemplate) Render(_ model.ActSnapshot) ([]renderer.Block, error) {
 	s.calls++
+
 	return s.blocks, nil
 }

@@ -135,18 +140,23 @@ func TestGetDocument_IdempotentAndHashed(t *testing.T) {
 	if err != nil {
 		t.Fatalf("GetDocument first call: %v", err)
 	}
-	if len(resp1.Content) == 0 {
+
+	if len(resp1.GetContent()) == 0 {
 		t.Fatalf("expected content on first call")
 	}

 	stored := record.Hashes[model.DocumentTypeAct]
+
 	if stored == "" {
 		t.Fatalf("expected stored hash")
 	}
-	footerHash := extractFooterHash(resp1.Content)
+
+	footerHash := extractFooterHash(resp1.GetContent())
+
 	if footerHash == "" {
 		t.Fatalf("expected footer hash in PDF")
 	}
+
 	if stored != footerHash {
 		t.Fatalf("stored hash mismatch: got %s", stored)
 	}
@@ -158,16 +168,19 @@ func TestGetDocument_IdempotentAndHashed(t *testing.T) {
 	if err != nil {
 		t.Fatalf("GetDocument second call: %v", err)
 	}
-	if !bytes.Equal(resp1.Content, resp2.Content) {
+
+	if !bytes.Equal(resp1.GetContent(), resp2.GetContent()) {
 		t.Fatalf("expected identical PDF bytes on second call")
 	}

 	if tmpl.calls != 1 {
 		t.Fatalf("expected template to be rendered once, got %d", tmpl.calls)
 	}
+
 	if store.saveCount != 1 {
 		t.Fatalf("expected document save once, got %d", store.saveCount)
 	}
+
 	if store.loadCount == 0 {
 		t.Fatalf("expected document load on second call")
 	}
@@ -176,17 +189,23 @@ func TestGetDocument_IdempotentAndHashed(t *testing.T) {
 func extractFooterHash(pdf []byte) string {
 	prefix := []byte("Document integrity hash: ")
 	idx := bytes.Index(pdf, prefix)
+
 	if idx == -1 {
 		return ""
 	}
+
 	start := idx + len(prefix)
+
 	end := start
+
 	for end < len(pdf) && isHexDigit(pdf[end]) {
 		end++
 	}
+
 	if end-start != 64 {
 		return ""
 	}
+
 	return string(pdf[start:end])
 }

--- a/api/billing/documents/internal/service/documents/template.go
+++ b/api/billing/documents/internal/service/documents/template.go
@@ -20,7 +20,7 @@ type templateRenderer struct {
 func newTemplateRenderer(path string) (*templateRenderer, error) {
 	data, err := os.ReadFile(path)
 	if err != nil {
-		return nil, fmt.Errorf("Read template: %w", err)
+		return nil, fmt.Errorf("read template: %w", err)
 	}

 	funcs := template.FuncMap{
@@ -30,7 +30,7 @@ func newTemplateRenderer(path string) (*templateRenderer, error) {

 	tpl, err := template.New("acceptance").Funcs(funcs).Option("missingkey=error").Parse(string(data))
 	if err != nil {
-		return nil, fmt.Errorf("Parse template: %w", err)
+		return nil, fmt.Errorf("parse template: %w", err)
 	}

 	return &templateRenderer{tpl: tpl}, nil
@@ -39,8 +39,9 @@ func newTemplateRenderer(path string) (*templateRenderer, error) {
 func (r *templateRenderer) Render(snapshot model.ActSnapshot) ([]renderer.Block, error) {
 	var buf bytes.Buffer
 	if err := r.tpl.Execute(&buf, snapshot); err != nil {
-		return nil, fmt.Errorf("Execute template: %w", err)
+		return nil, fmt.Errorf("execute template: %w", err)
 	}
+
 	return renderer.ParseBlocks(buf.String())
 }

@@ -49,6 +50,7 @@ func formatMoney(amount decimal.Decimal, currency string) string {
 	if currency == "" {
 		return amount.String()
 	}
+
 	return fmt.Sprintf("%s %s", amount.String(), currency)
 }

@@ -56,5 +58,6 @@ func formatDate(t time.Time) string {
 	if t.IsZero() {
 		return ""
 	}
+
 	return t.Format("2006-01-02")
 }
--- a/api/billing/documents/internal/service/documents/template_test.go
+++ b/api/billing/documents/internal/service/documents/template_test.go
@@ -2,6 +2,7 @@ package documents

 import (
 	"path/filepath"
+	"slices"
 	"testing"
 	"time"

@@ -12,6 +13,7 @@ import (

 func TestTemplateRenderer_Render(t *testing.T) {
 	path := filepath.Join("..", "..", "..", "templates", "acceptance.tpl")
+
 	tmpl, err := newTemplateRenderer(path)
 	if err != nil {
 		t.Fatalf("newTemplateRenderer: %v", err)
@@ -29,22 +31,18 @@ func TestTemplateRenderer_Render(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Render: %v", err)
 	}
+
 	if len(blocks) == 0 {
 		t.Fatalf("expected blocks, got none")
 	}

 	title := findBlock(blocks, renderer.TagTitle)
+
 	if title == nil {
 		t.Fatalf("expected title block")
 	}
-	foundTitle := false
-	for _, line := range title.Lines {
-		if line == "ACT OF ACCEPTANCE OF SERVICES" {
-			foundTitle = true
-			break
-		}
-	}
-	if !foundTitle {
+
+	if !slices.Contains(title.Lines, "ACT OF ACCEPTANCE OF SERVICES") {
 		t.Fatalf("expected title content not found")
 	}

@@ -52,13 +50,17 @@ func TestTemplateRenderer_Render(t *testing.T) {
 	if kv == nil {
 		t.Fatalf("expected kv block")
 	}
+
 	foundExecutor := false
+
 	for _, row := range kv.Rows {
 		if len(row) >= 2 && row[0] == "Executor" && row[1] == snapshot.ExecutorFullName {
 			foundExecutor = true
+
 			break
 		}
 	}
+
 	if !foundExecutor {
 		t.Fatalf("expected executor name in kv block")
 	}
@@ -67,13 +69,17 @@ func TestTemplateRenderer_Render(t *testing.T) {
 	if table == nil {
 		t.Fatalf("expected table block")
 	}
+
 	foundAmount := false
+
 	for _, row := range table.Rows {
 		if len(row) >= 2 && row[1] == "123.45 USD" {
 			foundAmount = true
+
 			break
 		}
 	}
+
 	if !foundAmount {
 		t.Fatalf("expected amount in table block")
 	}
@@ -85,5 +91,6 @@ func findBlock(blocks []renderer.Block, tag renderer.Tag) *renderer.Block {
 			return &blocks[i]
 		}
 	}
+
 	return nil
 }
--- a/api/billing/documents/renderer/header.go
+++ b/api/billing/documents/renderer/header.go
@@ -27,6 +27,7 @@ func drawHeader(pdf *gofpdf.Fpdf, issuer Issuer, marginLeft, marginTop float64)
 	if logoWidth > 0 {
 		textX = startX + logoWidth + 6
 	}
+
 	pdf.SetXY(textX, startY)
 	pdf.SetFont("Helvetica", "B", 12)
 	pdf.CellFormat(0, 5, issuer.LegalName, "", 1, "L", false, 0, "")
@@ -39,6 +40,7 @@ func drawHeader(pdf *gofpdf.Fpdf, issuer Issuer, marginLeft, marginTop float64)
 	}

 	currentY := pdf.GetY()
+
 	if logoWidth > 0 {
 		logoBottom := startY + logoWidth
 		if logoBottom > currentY {
--- a/api/billing/documents/renderer/layout.go
+++ b/api/billing/documents/renderer/layout.go
@@ -2,7 +2,6 @@ package renderer

 import (
 	"bytes"
-	"fmt"
 	"math"
 	"strings"

@@ -39,18 +38,22 @@ func (r Renderer) Render(blocks []Block, footerHash string) ([]byte, error) {
 	pdf.SetFooterFunc(func() {
 		pdf.SetY(-15)
 		pdf.SetFont("Helvetica", "", 8)
-		footer := fmt.Sprintf("Document integrity hash: %s", footerHash)
+
+		footer := "Document integrity hash: " + footerHash
 		pdf.CellFormat(0, 5, footer, "", 0, "L", false, 0, "")
 	})

 	pdf.AddPage()
+
 	if _, err := drawHeader(pdf, r.Issuer, pageMarginLeft, pageMarginTop); err != nil {
 		return nil, err
 	}
+
 	pdf.Ln(6)

 	for _, block := range blocks {
 		renderBlock(pdf, block)
+
 		if pdf.Error() != nil {
 			return nil, pdf.Error()
 		}
@@ -60,6 +63,7 @@ func (r Renderer) Render(blocks []Block, footerHash string) ([]byte, error) {
 	if err := pdf.Output(buf); err != nil {
 		return nil, err
 	}
+
 	return buf.Bytes(), nil
 }

@@ -69,47 +73,64 @@ func renderBlock(pdf *gofpdf.Fpdf, block Block) {
 		pdf.Ln(6)
 	case TagTitle:
 		pdf.SetFont("Helvetica", "B", 14)
+
 		for _, line := range block.Lines {
 			if strings.TrimSpace(line) == "" {
 				pdf.Ln(4)
+
 				continue
 			}
+
 			pdf.CellFormat(0, 7, line, "", 1, "C", false, 0, "")
 		}
+
 		pdf.Ln(2)
 	case TagSubtitle:
 		pdf.SetFont("Helvetica", "", 11)
+
 		for _, line := range block.Lines {
 			if strings.TrimSpace(line) == "" {
 				pdf.Ln(3)
+
 				continue
 			}
+
 			pdf.CellFormat(0, 6, line, "", 1, "C", false, 0, "")
 		}
+
 		pdf.Ln(2)
 	case TagMeta:
 		pdf.SetFont("Helvetica", "", 9)
+
 		for _, line := range block.Lines {
 			if strings.TrimSpace(line) == "" {
 				pdf.Ln(2)
+
 				continue
 			}
+
 			pdf.CellFormat(0, 4.5, line, "", 1, "R", false, 0, "")
 		}
+
 		pdf.Ln(2)
 	case TagSection:
 		pdf.Ln(2)
 		pdf.SetFont("Helvetica", "B", 11)
+
 		for _, line := range block.Lines {
 			if strings.TrimSpace(line) == "" {
 				pdf.Ln(3)
+
 				continue
 			}
+
 			pdf.CellFormat(0, 6, line, "", 1, "L", false, 0, "")
 		}
+
 		pdf.Ln(1)
 	case TagText:
 		pdf.SetFont("Helvetica", "", 10)
+
 		text := strings.Join(block.Lines, "\n")
 		pdf.MultiCell(0, 5, text, "", "L", false)
 		pdf.Ln(1)
@@ -119,12 +140,14 @@ func renderBlock(pdf *gofpdf.Fpdf, block Block) {
 		renderTable(pdf, block)
 	case TagSign:
 		pdf.SetFont("Helvetica", "", 10)
+
 		text := strings.Join(block.Lines, "\n")
 		pdf.MultiCell(0, 6, text, "", "L", false)
 		pdf.Ln(2)
 	default:
 		// Unknown tag: treat as plain text for resilience.
 		pdf.SetFont("Helvetica", "", 10)
+
 		text := strings.Join(block.Lines, "\n")
 		pdf.MultiCell(0, 5, text, "", "L", false)
 		pdf.Ln(1)
@@ -133,6 +156,7 @@ func renderBlock(pdf *gofpdf.Fpdf, block Block) {

 func renderKeyValue(pdf *gofpdf.Fpdf, block Block) {
 	pdf.SetFont("Helvetica", "", 10)
+
 	usable := usableWidth(pdf)
 	keyWidth := math.Round(usable * 0.35)
 	valueWidth := usable - keyWidth
@@ -142,11 +166,14 @@ func renderKeyValue(pdf *gofpdf.Fpdf, block Block) {
 		if len(row) == 0 {
 			continue
 		}
+
 		key := row[0]
+
 		value := ""
 		if len(row) > 1 {
 			value = row[1]
 		}
+
 		x := pdf.GetX()
 		y := pdf.GetY()

@@ -162,6 +189,7 @@ func renderKeyValue(pdf *gofpdf.Fpdf, block Block) {

 		pdf.SetY(maxFloat(leftY, rightY))
 	}
+
 	pdf.Ln(1)
 }

@@ -169,6 +197,7 @@ func renderTable(pdf *gofpdf.Fpdf, block Block) {
 	if len(block.Rows) == 0 {
 		return
 	}
+
 	usable := usableWidth(pdf)
 	col1 := math.Round(usable * 0.7)
 	col2 := usable - col1
@@ -176,9 +205,11 @@ func renderTable(pdf *gofpdf.Fpdf, block Block) {

 	header := block.Rows[0]
 	pdf.SetFont("Helvetica", "B", 10)
+
 	if len(header) > 0 {
 		pdf.CellFormat(col1, lineHeight, header[0], "1", 0, "L", false, 0, "")
 	}
+
 	if len(header) > 1 {
 		pdf.CellFormat(col2, lineHeight, header[1], "1", 1, "R", false, 0, "")
 	} else {
@@ -186,15 +217,19 @@ func renderTable(pdf *gofpdf.Fpdf, block Block) {
 	}

 	pdf.SetFont("Helvetica", "", 10)
+
 	for _, row := range block.Rows[1:] {
 		colA := ""
 		colB := ""
+
 		if len(row) > 0 {
 			colA = row[0]
 		}
+
 		if len(row) > 1 {
 			colB = row[1]
 		}
+
 		x := pdf.GetX()
 		y := pdf.GetY()
 		pdf.MultiCell(col1, lineHeight, colA, "1", "L", false)
@@ -204,12 +239,14 @@ func renderTable(pdf *gofpdf.Fpdf, block Block) {
 		rightY := pdf.GetY()
 		pdf.SetY(maxFloat(leftY, rightY))
 	}
+
 	pdf.Ln(2)
 }

 func usableWidth(pdf *gofpdf.Fpdf) float64 {
 	pageW, _ := pdf.GetPageSize()
 	left, _, right, _ := pdf.GetMargins()
+
 	return pageW - left - right
 }

@@ -217,5 +254,6 @@ func maxFloat(a, b float64) float64 {
 	if a > b {
 		return a
 	}
+
 	return b
 }
--- a/api/billing/documents/renderer/renderer_test.go
+++ b/api/billing/documents/renderer/renderer_test.go
@@ -26,11 +26,13 @@ func TestRenderer_RenderContainsText(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Render: %v", err)
 	}
+
 	if len(pdfBytes) == 0 {
 		t.Fatalf("expected PDF bytes")
 	}

 	checks := []string{"Sendico Ltd", "Jane Doe", "100 USD", "Document integrity hash"}
+
 	for _, token := range checks {
 		if !containsPDFText(pdfBytes, token) {
 			t.Fatalf("expected PDF to contain %q", token)
@@ -42,22 +44,29 @@ func containsPDFText(pdfBytes []byte, text string) bool {
 	if bytes.Contains(pdfBytes, []byte(text)) {
 		return true
 	}
+
 	hexText := hex.EncodeToString([]byte(text))
+
 	if bytes.Contains(pdfBytes, []byte(strings.ToUpper(hexText))) {
 		return true
 	}
+
 	if bytes.Contains(pdfBytes, []byte(strings.ToLower(hexText))) {
 		return true
 	}

 	utf16Bytes := encodeUTF16BE(text, false)
+
 	if bytes.Contains(pdfBytes, utf16Bytes) {
 		return true
 	}
+
 	utf16Hex := hex.EncodeToString(utf16Bytes)
+
 	if bytes.Contains(pdfBytes, []byte(strings.ToUpper(utf16Hex))) {
 		return true
 	}
+
 	if bytes.Contains(pdfBytes, []byte(strings.ToLower(utf16Hex))) {
 		return true
 	}
@@ -66,25 +75,33 @@ func containsPDFText(pdfBytes []byte, text string) bool {
 	if bytes.Contains(pdfBytes, utf16BytesBOM) {
 		return true
 	}
+
 	utf16HexBOM := hex.EncodeToString(utf16BytesBOM)
+
 	if bytes.Contains(pdfBytes, []byte(strings.ToUpper(utf16HexBOM))) {
 		return true
 	}
+
 	return bytes.Contains(pdfBytes, []byte(strings.ToLower(utf16HexBOM)))
 }

 func encodeUTF16BE(text string, withBOM bool) []byte {
 	encoded := utf16.Encode([]rune(text))
 	length := len(encoded) * 2
+
 	if withBOM {
 		length += 2
 	}
+
 	out := make([]byte, 0, length)
+
 	if withBOM {
 		out = append(out, 0xFE, 0xFF)
 	}
+
 	for _, v := range encoded {
 		out = append(out, byte(v>>8), byte(v))
 	}
+
 	return out
 }
--- a/api/billing/documents/renderer/tags.go
+++ b/api/billing/documents/renderer/tags.go
@@ -32,6 +32,7 @@ type Block struct {
 func ParseBlocks(input string) ([]Block, error) {
 	scanner := bufio.NewScanner(strings.NewReader(input))
 	blocks := make([]Block, 0)
+
 	var current *Block

 	flush := func() {
@@ -44,17 +45,24 @@ func ParseBlocks(input string) ([]Block, error) {
 	for scanner.Scan() {
 		line := strings.TrimRight(scanner.Text(), "\r")
 		trimmed := strings.TrimSpace(line)
+
 		if strings.HasPrefix(trimmed, "#") {
 			flush()
+
 			tag := Tag(strings.TrimSpace(strings.TrimPrefix(trimmed, "#")))
+
 			if tag == "" {
 				continue
 			}
+
 			if tag == TagSpacer {
 				blocks = append(blocks, Block{Tag: TagSpacer})
+
 				continue
 			}
+
 			current = &Block{Tag: tag}
+
 			continue
 		}

@@ -62,16 +70,19 @@ func ParseBlocks(input string) ([]Block, error) {
 			continue
 		}

-		switch current.Tag {
+		switch current.Tag { //nolint:exhaustive // only KV and Table need row parsing
 		case TagKV, TagTable:
 			if trimmed == "" {
 				continue
 			}
+
 			parts := strings.Split(line, "|")
+
 			row := make([]string, 0, len(parts))
 			for _, part := range parts {
 				row = append(row, strings.TrimSpace(part))
 			}
+
 			current.Rows = append(current.Rows, row)
 		default:
 			current.Lines = append(current.Lines, line)
@@ -79,9 +90,10 @@ func ParseBlocks(input string) ([]Block, error) {
 	}

 	if err := scanner.Err(); err != nil {
-		return nil, fmt.Errorf("Parse blocks: %w", err)
+		return nil, fmt.Errorf("parse blocks: %w", err)
 	}

 	flush()
+
 	return blocks, nil
 }
--- a/api/billing/documents/storage/model/document.go
+++ b/api/billing/documents/storage/model/document.go
@@ -28,6 +28,7 @@ func DocumentTypeFromProto(t documentsv1.DocumentType) DocumentType {
 	if name, ok := documentsv1.DocumentType_name[int32(t)]; ok {
 		return DocumentType(name)
 	}
+
 	return DocumentTypeUnspecified
 }

@@ -36,22 +37,24 @@ func (t DocumentType) Proto() documentsv1.DocumentType {
 	if value, ok := documentsv1.DocumentType_value[string(t)]; ok {
 		return documentsv1.DocumentType(value)
 	}
+
 	return documentsv1.DocumentType_DOCUMENT_TYPE_UNSPECIFIED
 }

 // ActSnapshot captures the immutable data needed to generate an acceptance act.
 type ActSnapshot struct {
-	PaymentID        string          `bson:"paymentId" json:"paymentId"`
-	Date             time.Time       `bson:"date" json:"date"`
+	PaymentID        string          `bson:"paymentId"        json:"paymentId"`
+	Date             time.Time       `bson:"date"             json:"date"`
 	ExecutorFullName string          `bson:"executorFullName" json:"executorFullName"`
-	Amount           decimal.Decimal `bson:"amount" json:"amount"`
-	Currency         string          `bson:"currency" json:"currency"`
+	Amount           decimal.Decimal `bson:"amount"           json:"amount"`
+	Currency         string          `bson:"currency"         json:"currency"`
 }

 func (s *ActSnapshot) Normalize() {
 	if s == nil {
 		return
 	}
+
 	s.PaymentID = strings.TrimSpace(s.PaymentID)
 	s.ExecutorFullName = strings.TrimSpace(s.ExecutorFullName)
 	s.Currency = strings.TrimSpace(s.Currency)
@@ -60,21 +63,25 @@ func (s *ActSnapshot) Normalize() {
 // DocumentRecord stores document metadata and cached artefacts for a payment.
 type DocumentRecord struct {
 	storable.Base `bson:",inline" json:",inline"`
-	PaymentRef    string                  `bson:"paymentRef" json:"paymentRef"`
-	Snapshot      ActSnapshot             `bson:"snapshot" json:"snapshot"`
-	StoragePaths  map[DocumentType]string `bson:"storagePaths,omitempty" json:"storagePaths,omitempty"`
-	Hashes        map[DocumentType]string `bson:"hashes,omitempty" json:"hashes,omitempty"`
+
+	PaymentRef   string                  `bson:"paymentRef"             json:"paymentRef"`
+	Snapshot     ActSnapshot             `bson:"snapshot"               json:"snapshot"`
+	StoragePaths map[DocumentType]string `bson:"storagePaths,omitempty" json:"storagePaths,omitempty"`
+	Hashes       map[DocumentType]string `bson:"hashes,omitempty"       json:"hashes,omitempty"`
 }

 func (r *DocumentRecord) Normalize() {
 	if r == nil {
 		return
 	}
+
 	r.PaymentRef = strings.TrimSpace(r.PaymentRef)
 	r.Snapshot.Normalize()
+
 	if r.StoragePaths == nil {
 		r.StoragePaths = map[DocumentType]string{}
 	}
+
 	if r.Hashes == nil {
 		r.Hashes = map[DocumentType]string{}
 	}
--- a/api/billing/documents/storage/mongo/repository.go
+++ b/api/billing/documents/storage/mongo/repository.go
@@ -43,17 +43,21 @@ func New(logger mlogger.Logger, conn *db.MongoConnection) (*Store, error) {

 	if err := result.Ping(ctx); err != nil {
 		result.logger.Error("Mongo ping failed during store init", zap.Error(err))
+
 		return nil, err
 	}

 	documentsStore, err := store.NewDocuments(result.logger, database)
 	if err != nil {
 		result.logger.Error("Failed to initialise documents store", zap.Error(err))
+
 		return nil, err
 	}
+
 	result.documents = documentsStore

 	result.logger.Info("Billing documents MongoDB storage initialised")
+
 	return result, nil
 }

--- a/api/billing/documents/storage/mongo/store/documents.go
+++ b/api/billing/documents/storage/mongo/store/documents.go
@@ -39,6 +39,7 @@ func NewDocuments(logger mlogger.Logger, db *mongo.Database) (*Documents, error)
 	for _, def := range indexes {
 		if err := repo.CreateIndex(def); err != nil {
 			logger.Error("Failed to ensure documents index", zap.Error(err), zap.String("collection", repo.Collection()))
+
 			return nil, err
 		}
 	}
@@ -56,7 +57,9 @@ func (d *Documents) Create(ctx context.Context, record *model.DocumentRecord) er
 	if record == nil {
 		return merrors.InvalidArgument("documentsStore: nil record")
 	}
+
 	record.Normalize()
+
 	if record.PaymentRef == "" {
 		return merrors.InvalidArgument("documentsStore: empty paymentRef")
 	}
@@ -66,9 +69,12 @@ func (d *Documents) Create(ctx context.Context, record *model.DocumentRecord) er
 		if errors.Is(err, merrors.ErrDataConflict) {
 			return storage.ErrDuplicateDocument
 		}
+
 		return err
 	}
+
 	d.logger.Debug("Document record created", zap.String("payment_ref", record.PaymentRef))
+
 	return nil
 }

@@ -76,17 +82,21 @@ func (d *Documents) Update(ctx context.Context, record *model.DocumentRecord) er
 	if record == nil {
 		return merrors.InvalidArgument("documentsStore: nil record")
 	}
+
 	if record.ID.IsZero() {
 		return merrors.InvalidArgument("documentsStore: missing record id")
 	}
+
 	record.Normalize()
 	record.Update()
 	if err := d.repo.Update(ctx, record); err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
 			return storage.ErrDocumentNotFound
 		}
+
 		return err
 	}
+
 	return nil
 }

@@ -101,8 +111,10 @@ func (d *Documents) GetByPaymentRef(ctx context.Context, paymentRef string) (*mo
 		if errors.Is(err, merrors.ErrNoData) {
 			return nil, storage.ErrDocumentNotFound
 		}
+
 		return nil, err
 	}
+
 	return entity, nil
 }

@@ -113,26 +125,34 @@ func (d *Documents) ListByPaymentRefs(ctx context.Context, paymentRefs []string)
 		if clean == "" {
 			continue
 		}
+
 		refs = append(refs, clean)
 	}
+
 	if len(refs) == 0 {
 		return []*model.DocumentRecord{}, nil
 	}

 	query := repository.Query().Comparison(repository.Field("paymentRef"), builder.In, refs)
 	records := make([]*model.DocumentRecord, 0)
+
 	decoder := func(cur *mongo.Cursor) error {
 		var rec model.DocumentRecord
 		if err := cur.Decode(&rec); err != nil {
 			d.logger.Warn("Failed to decode document record", zap.Error(err))
+
 			return err
 		}
+
 		records = append(records, &rec)
+
 		return nil
 	}
+
 	if err := d.repo.FindManyByFilter(ctx, query, decoder); err != nil {
 		return nil, err
 	}
+
 	return records, nil
 }