Add background sync worker and complete local-first architecture

Implements automatic background synchronization every 5 minutes: - Worker pushes pending changes to server (PushPendingChanges) - Worker pulls new pricelists (SyncPricelistsIfNeeded) - Graceful shutdown with context cancellation - Automatic online/offline detection via DB ping New files: - internal/services/sync/worker.go - Background sync worker - internal/services/local_configuration.go - Local-first CRUD - internal/localdb/converters.go - MariaDB ↔ SQLite converters Extended sync infrastructure: - Pending changes queue (pending_changes table) - Push/pull sync endpoints (/api/sync/push, /pending) - ConfigurationGetter interface for handler compatibility - LocalConfigurationService replaces ConfigurationService All configuration operations now run through SQLite with automatic background sync to MariaDB when online. Phase 2.5 nearly complete. Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2026-02-01 22:17:00 +03:00
parent 143d217397
commit be77256d4e
11 changed files with 1131 additions and 27 deletions
--- a/internal/services/configuration.go
+++ b/internal/services/configuration.go
@@ -14,6 +14,12 @@ var (
 	ErrConfigForbidden  = errors.New("access to configuration forbidden")
 )

+// ConfigurationGetter is an interface for services that can retrieve configurations
+// Used by handlers to work with both ConfigurationService and LocalConfigurationService
+type ConfigurationGetter interface {
+	GetByUUID(uuid string, userID uint) (*models.Configuration, error)
+}
+
 type ConfigurationService struct {
 	configRepo    *repository.ConfigurationRepository
 	componentRepo *repository.ComponentRepository
--- a/internal/services/local_configuration.go
+++ b/internal/services/local_configuration.go
@@ -0,0 +1,509 @@
+package services
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+
+	"github.com/google/uuid"
+	"git.mchus.pro/mchus/quoteforge/internal/localdb"
+	"git.mchus.pro/mchus/quoteforge/internal/models"
+	"git.mchus.pro/mchus/quoteforge/internal/services/sync"
+)
+
+// LocalConfigurationService handles configurations in local-first mode
+// All operations go through SQLite, MariaDB is used only for sync
+type LocalConfigurationService struct {
+	localDB      *localdb.LocalDB
+	syncService  *sync.Service
+	quoteService *QuoteService
+	isOnline     func() bool // Function to check if we're online
+}
+
+// NewLocalConfigurationService creates a new local-first configuration service
+func NewLocalConfigurationService(
+	localDB *localdb.LocalDB,
+	syncService *sync.Service,
+	quoteService *QuoteService,
+	isOnline func() bool,
+) *LocalConfigurationService {
+	return &LocalConfigurationService{
+		localDB:      localDB,
+		syncService:  syncService,
+		quoteService: quoteService,
+		isOnline:     isOnline,
+	}
+}
+
+// Create creates a new configuration in local SQLite and queues it for sync
+func (s *LocalConfigurationService) Create(userID uint, req *CreateConfigRequest) (*models.Configuration, error) {
+	// If online, check for new pricelists first
+	if s.isOnline() {
+		if err := s.syncService.SyncPricelistsIfNeeded(); err != nil {
+			// Log but don't fail - we can still use local pricelists
+		}
+	}
+
+	total := req.Items.Total()
+	if req.ServerCount > 1 {
+		total *= float64(req.ServerCount)
+	}
+
+	cfg := &models.Configuration{
+		UUID:        uuid.New().String(),
+		UserID:      userID,
+		Name:        req.Name,
+		Items:       req.Items,
+		TotalPrice:  &total,
+		CustomPrice: req.CustomPrice,
+		Notes:       req.Notes,
+		IsTemplate:  req.IsTemplate,
+		ServerCount: req.ServerCount,
+		CreatedAt:   time.Now(),
+	}
+
+	// Convert to local model
+	localCfg := localdb.ConfigurationToLocal(cfg)
+
+	// Save to local SQLite
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	// Add to pending sync queue
+	payload, err := json.Marshal(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", cfg.UUID, "create", string(payload)); err != nil {
+		return nil, err
+	}
+
+	// Record usage stats
+	_ = s.quoteService.RecordUsage(req.Items)
+
+	return cfg, nil
+}
+
+// GetByUUID returns a configuration from local SQLite
+func (s *LocalConfigurationService) GetByUUID(uuid string, userID uint) (*models.Configuration, error) {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return nil, ErrConfigNotFound
+	}
+
+	// Convert to models.Configuration
+	cfg := localdb.LocalToConfiguration(localCfg)
+
+	// Allow access if user owns config or it's a template
+	if cfg.UserID != userID && !cfg.IsTemplate {
+		return nil, ErrConfigForbidden
+	}
+
+	return cfg, nil
+}
+
+// Update updates a configuration in local SQLite and queues it for sync
+func (s *LocalConfigurationService) Update(uuid string, userID uint, req *CreateConfigRequest) (*models.Configuration, error) {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return nil, ErrConfigNotFound
+	}
+
+	if localCfg.OriginalUserID != userID {
+		return nil, ErrConfigForbidden
+	}
+
+	total := req.Items.Total()
+	if req.ServerCount > 1 {
+		total *= float64(req.ServerCount)
+	}
+
+	// Update fields
+	localCfg.Name = req.Name
+	localCfg.Items = localdb.LocalConfigItems{}
+	for _, item := range req.Items {
+		localCfg.Items = append(localCfg.Items, localdb.LocalConfigItem{
+			LotName:   item.LotName,
+			Quantity:  item.Quantity,
+			UnitPrice: item.UnitPrice,
+		})
+	}
+	localCfg.TotalPrice = &total
+	localCfg.CustomPrice = req.CustomPrice
+	localCfg.Notes = req.Notes
+	localCfg.IsTemplate = req.IsTemplate
+	localCfg.ServerCount = req.ServerCount
+	localCfg.UpdatedAt = time.Now()
+	localCfg.SyncStatus = "pending"
+
+	// Save to local SQLite
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	// Add to pending sync queue
+	cfg := localdb.LocalToConfiguration(localCfg)
+	payload, err := json.Marshal(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", uuid, "update", string(payload)); err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+// Delete deletes a configuration from local SQLite and queues it for sync
+func (s *LocalConfigurationService) Delete(uuid string, userID uint) error {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return ErrConfigNotFound
+	}
+
+	if localCfg.OriginalUserID != userID {
+		return ErrConfigForbidden
+	}
+
+	// Delete from local SQLite
+	if err := s.localDB.DeleteConfiguration(uuid); err != nil {
+		return err
+	}
+
+	// Add to pending sync queue
+	if err := s.localDB.AddPendingChange("configuration", uuid, "delete", ""); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Rename renames a configuration
+func (s *LocalConfigurationService) Rename(uuid string, userID uint, newName string) (*models.Configuration, error) {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return nil, ErrConfigNotFound
+	}
+
+	if localCfg.OriginalUserID != userID {
+		return nil, ErrConfigForbidden
+	}
+
+	localCfg.Name = newName
+	localCfg.UpdatedAt = time.Now()
+	localCfg.SyncStatus = "pending"
+
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	// Add to pending sync queue
+	cfg := localdb.LocalToConfiguration(localCfg)
+	payload, err := json.Marshal(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", uuid, "update", string(payload)); err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+// Clone clones a configuration
+func (s *LocalConfigurationService) Clone(configUUID string, userID uint, newName string) (*models.Configuration, error) {
+	original, err := s.GetByUUID(configUUID, userID)
+	if err != nil {
+		return nil, err
+	}
+
+	total := original.Items.Total()
+	if original.ServerCount > 1 {
+		total *= float64(original.ServerCount)
+	}
+
+	clone := &models.Configuration{
+		UUID:        uuid.New().String(),
+		UserID:      userID,
+		Name:        newName,
+		Items:       original.Items,
+		TotalPrice:  &total,
+		CustomPrice: original.CustomPrice,
+		Notes:       original.Notes,
+		IsTemplate:  false,
+		ServerCount: original.ServerCount,
+		CreatedAt:   time.Now(),
+	}
+
+	localCfg := localdb.ConfigurationToLocal(clone)
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	// Add to pending sync queue
+	payload, err := json.Marshal(clone)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", clone.UUID, "create", string(payload)); err != nil {
+		return nil, err
+	}
+
+	return clone, nil
+}
+
+// ListByUser returns all configurations for a user from local SQLite
+func (s *LocalConfigurationService) ListByUser(userID uint, page, perPage int) ([]models.Configuration, int64, error) {
+	// Get all local configurations
+	localConfigs, err := s.localDB.GetConfigurations()
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Filter by user
+	var userConfigs []models.Configuration
+	for _, lc := range localConfigs {
+		if lc.OriginalUserID == userID || lc.IsTemplate {
+			userConfigs = append(userConfigs, *localdb.LocalToConfiguration(&lc))
+		}
+	}
+
+	total := int64(len(userConfigs))
+
+	// Apply pagination
+	if page < 1 {
+		page = 1
+	}
+	if perPage < 1 || perPage > 100 {
+		perPage = 20
+	}
+	offset := (page - 1) * perPage
+
+	start := offset
+	if start > len(userConfigs) {
+		start = len(userConfigs)
+	}
+	end := start + perPage
+	if end > len(userConfigs) {
+		end = len(userConfigs)
+	}
+
+	return userConfigs[start:end], total, nil
+}
+
+// RefreshPrices updates all component prices in the configuration
+func (s *LocalConfigurationService) RefreshPrices(uuid string, userID uint) (*models.Configuration, error) {
+	// This requires access to component prices from local cache
+	// For now, return error as we need to implement component price lookup from local cache
+	return nil, errors.New("refresh prices not yet implemented for local-first mode")
+}
+
+// GetByUUIDNoAuth returns configuration without ownership check
+func (s *LocalConfigurationService) GetByUUIDNoAuth(uuid string) (*models.Configuration, error) {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return nil, ErrConfigNotFound
+	}
+	return localdb.LocalToConfiguration(localCfg), nil
+}
+
+// UpdateNoAuth updates configuration without ownership check
+func (s *LocalConfigurationService) UpdateNoAuth(uuid string, req *CreateConfigRequest) (*models.Configuration, error) {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return nil, ErrConfigNotFound
+	}
+
+	total := req.Items.Total()
+	if req.ServerCount > 1 {
+		total *= float64(req.ServerCount)
+	}
+
+	localCfg.Name = req.Name
+	localCfg.Items = localdb.LocalConfigItems{}
+	for _, item := range req.Items {
+		localCfg.Items = append(localCfg.Items, localdb.LocalConfigItem{
+			LotName:   item.LotName,
+			Quantity:  item.Quantity,
+			UnitPrice: item.UnitPrice,
+		})
+	}
+	localCfg.TotalPrice = &total
+	localCfg.CustomPrice = req.CustomPrice
+	localCfg.Notes = req.Notes
+	localCfg.IsTemplate = req.IsTemplate
+	localCfg.ServerCount = req.ServerCount
+	localCfg.UpdatedAt = time.Now()
+	localCfg.SyncStatus = "pending"
+
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	cfg := localdb.LocalToConfiguration(localCfg)
+	payload, err := json.Marshal(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", uuid, "update", string(payload)); err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+// DeleteNoAuth deletes configuration without ownership check
+func (s *LocalConfigurationService) DeleteNoAuth(uuid string) error {
+	if err := s.localDB.DeleteConfiguration(uuid); err != nil {
+		return err
+	}
+	return s.localDB.AddPendingChange("configuration", uuid, "delete", "")
+}
+
+// RenameNoAuth renames configuration without ownership check
+func (s *LocalConfigurationService) RenameNoAuth(uuid string, newName string) (*models.Configuration, error) {
+	localCfg, err := s.localDB.GetConfigurationByUUID(uuid)
+	if err != nil {
+		return nil, ErrConfigNotFound
+	}
+
+	localCfg.Name = newName
+	localCfg.UpdatedAt = time.Now()
+	localCfg.SyncStatus = "pending"
+
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	cfg := localdb.LocalToConfiguration(localCfg)
+	payload, err := json.Marshal(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", uuid, "update", string(payload)); err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+// CloneNoAuth clones configuration without ownership check
+func (s *LocalConfigurationService) CloneNoAuth(configUUID string, newName string, userID uint) (*models.Configuration, error) {
+	original, err := s.GetByUUIDNoAuth(configUUID)
+	if err != nil {
+		return nil, err
+	}
+
+	total := original.Items.Total()
+	if original.ServerCount > 1 {
+		total *= float64(original.ServerCount)
+	}
+
+	clone := &models.Configuration{
+		UUID:        uuid.New().String(),
+		UserID:      userID,
+		Name:        newName,
+		Items:       original.Items,
+		TotalPrice:  &total,
+		CustomPrice: original.CustomPrice,
+		Notes:       original.Notes,
+		IsTemplate:  false,
+		ServerCount: original.ServerCount,
+		CreatedAt:   time.Now(),
+	}
+
+	localCfg := localdb.ConfigurationToLocal(clone)
+	if err := s.localDB.SaveConfiguration(localCfg); err != nil {
+		return nil, err
+	}
+
+	payload, err := json.Marshal(clone)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.localDB.AddPendingChange("configuration", clone.UUID, "create", string(payload)); err != nil {
+		return nil, err
+	}
+
+	return clone, nil
+}
+
+// ListAll returns all configurations without user filter
+func (s *LocalConfigurationService) ListAll(page, perPage int) ([]models.Configuration, int64, error) {
+	localConfigs, err := s.localDB.GetConfigurations()
+	if err != nil {
+		return nil, 0, err
+	}
+
+	configs := make([]models.Configuration, len(localConfigs))
+	for i, lc := range localConfigs {
+		configs[i] = *localdb.LocalToConfiguration(&lc)
+	}
+
+	total := int64(len(configs))
+
+	// Apply pagination
+	if page < 1 {
+		page = 1
+	}
+	if perPage < 1 || perPage > 100 {
+		perPage = 20
+	}
+	offset := (page - 1) * perPage
+
+	start := offset
+	if start > len(configs) {
+		start = len(configs)
+	}
+	end := start + perPage
+	if end > len(configs) {
+		end = len(configs)
+	}
+
+	return configs[start:end], total, nil
+}
+
+// ListTemplates returns all template configurations
+func (s *LocalConfigurationService) ListTemplates(page, perPage int) ([]models.Configuration, int64, error) {
+	localConfigs, err := s.localDB.GetConfigurations()
+	if err != nil {
+		return nil, 0, err
+	}
+
+	var templates []models.Configuration
+	for _, lc := range localConfigs {
+		if lc.IsTemplate {
+			templates = append(templates, *localdb.LocalToConfiguration(&lc))
+		}
+	}
+
+	total := int64(len(templates))
+
+	// Apply pagination
+	if page < 1 {
+		page = 1
+	}
+	if perPage < 1 || perPage > 100 {
+		perPage = 20
+	}
+	offset := (page - 1) * perPage
+
+	start := offset
+	if start > len(templates) {
+		start = len(templates)
+	}
+	end := start + perPage
+	if end > len(templates) {
+		end = len(templates)
+	}
+
+	return templates[start:end], total, nil
+}
+
+// RefreshPricesNoAuth updates all component prices in the configuration without ownership check
+func (s *LocalConfigurationService) RefreshPricesNoAuth(uuid string) (*models.Configuration, error) {
+	// This requires access to component prices from local cache
+	// For now, return error as we need to implement component price lookup from local cache
+	return nil, errors.New("refresh prices not yet implemented for local-first mode")
+}
--- a/internal/services/sync/service.go
+++ b/internal/services/sync/service.go
@@ -1,24 +1,28 @@
 package sync

 import (
+	"encoding/json"
 	"fmt"
 	"log/slog"
 	"time"

 	"git.mchus.pro/mchus/quoteforge/internal/localdb"
+	"git.mchus.pro/mchus/quoteforge/internal/models"
 	"git.mchus.pro/mchus/quoteforge/internal/repository"
 )

 // Service handles synchronization between MariaDB and local SQLite
 type Service struct {
 	pricelistRepo *repository.PricelistRepository
+	configRepo    *repository.ConfigurationRepository
 	localDB       *localdb.LocalDB
 }

 // NewService creates a new sync service
-func NewService(pricelistRepo *repository.PricelistRepository, localDB *localdb.LocalDB) *Service {
+func NewService(pricelistRepo *repository.PricelistRepository, configRepo *repository.ConfigurationRepository, localDB *localdb.LocalDB) *Service {
 	return &Service{
 		pricelistRepo: pricelistRepo,
+		configRepo:    configRepo,
 		localDB:       localDB,
 	}
 }
@@ -213,3 +217,157 @@ func (s *Service) GetPricelistForOffline(serverPricelistID uint) (*localdb.Local

 	return localPL, nil
 }
+
+// SyncPricelistsIfNeeded checks for new pricelists and syncs if needed
+// This should be called before creating a new configuration when online
+func (s *Service) SyncPricelistsIfNeeded() error {
+	needSync, err := s.NeedSync()
+	if err != nil {
+		slog.Warn("failed to check if sync needed", "error", err)
+		return nil // Don't fail on check error
+	}
+
+	if !needSync {
+		slog.Debug("pricelists are up to date, no sync needed")
+		return nil
+	}
+
+	slog.Info("new pricelists detected, syncing...")
+	_, err = s.SyncPricelists()
+	if err != nil {
+		return fmt.Errorf("syncing pricelists: %w", err)
+	}
+
+	return nil
+}
+
+// PushPendingChanges pushes all pending changes to the server
+func (s *Service) PushPendingChanges() (int, error) {
+	changes, err := s.localDB.GetPendingChanges()
+	if err != nil {
+		return 0, fmt.Errorf("getting pending changes: %w", err)
+	}
+
+	if len(changes) == 0 {
+		slog.Debug("no pending changes to push")
+		return 0, nil
+	}
+
+	slog.Info("pushing pending changes", "count", len(changes))
+	pushed := 0
+	var syncedIDs []int64
+
+	for _, change := range changes {
+		err := s.pushSingleChange(&change)
+		if err != nil {
+			slog.Warn("failed to push change", "id", change.ID, "type", change.EntityType, "operation", change.Operation, "error", err)
+			// Increment attempts
+			s.localDB.IncrementPendingChangeAttempts(change.ID, err.Error())
+			continue
+		}
+
+		syncedIDs = append(syncedIDs, change.ID)
+		pushed++
+	}
+
+	// Mark synced changes as complete by deleting them
+	if len(syncedIDs) > 0 {
+		if err := s.localDB.MarkChangesSynced(syncedIDs); err != nil {
+			slog.Error("failed to mark changes as synced", "error", err)
+		}
+	}
+
+	slog.Info("pending changes pushed", "pushed", pushed, "failed", len(changes)-pushed)
+	return pushed, nil
+}
+
+// pushSingleChange pushes a single pending change to the server
+func (s *Service) pushSingleChange(change *localdb.PendingChange) error {
+	switch change.EntityType {
+	case "configuration":
+		return s.pushConfigurationChange(change)
+	default:
+		return fmt.Errorf("unknown entity type: %s", change.EntityType)
+	}
+}
+
+// pushConfigurationChange pushes a configuration change to the server
+func (s *Service) pushConfigurationChange(change *localdb.PendingChange) error {
+	switch change.Operation {
+	case "create":
+		return s.pushConfigurationCreate(change)
+	case "update":
+		return s.pushConfigurationUpdate(change)
+	case "delete":
+		return s.pushConfigurationDelete(change)
+	default:
+		return fmt.Errorf("unknown operation: %s", change.Operation)
+	}
+}
+
+// pushConfigurationCreate creates a configuration on the server
+func (s *Service) pushConfigurationCreate(change *localdb.PendingChange) error {
+	var cfg models.Configuration
+	if err := json.Unmarshal([]byte(change.Payload), &cfg); err != nil {
+		return fmt.Errorf("unmarshaling configuration: %w", err)
+	}
+
+	// Create on server
+	if err := s.configRepo.Create(&cfg); err != nil {
+		return fmt.Errorf("creating configuration on server: %w", err)
+	}
+
+	// Update local configuration with server ID
+	localCfg, err := s.localDB.GetConfigurationByUUID(cfg.UUID)
+	if err == nil {
+		serverID := cfg.ID
+		localCfg.ServerID = &serverID
+		localCfg.SyncStatus = "synced"
+		s.localDB.SaveConfiguration(localCfg)
+	}
+
+	slog.Info("configuration created on server", "uuid", cfg.UUID, "server_id", cfg.ID)
+	return nil
+}
+
+// pushConfigurationUpdate updates a configuration on the server
+func (s *Service) pushConfigurationUpdate(change *localdb.PendingChange) error {
+	var cfg models.Configuration
+	if err := json.Unmarshal([]byte(change.Payload), &cfg); err != nil {
+		return fmt.Errorf("unmarshaling configuration: %w", err)
+	}
+
+	// Update on server
+	if err := s.configRepo.Update(&cfg); err != nil {
+		return fmt.Errorf("updating configuration on server: %w", err)
+	}
+
+	// Update local sync status
+	localCfg, err := s.localDB.GetConfigurationByUUID(cfg.UUID)
+	if err == nil {
+		localCfg.SyncStatus = "synced"
+		s.localDB.SaveConfiguration(localCfg)
+	}
+
+	slog.Info("configuration updated on server", "uuid", cfg.UUID)
+	return nil
+}
+
+// pushConfigurationDelete deletes a configuration from the server
+func (s *Service) pushConfigurationDelete(change *localdb.PendingChange) error {
+	// Get the configuration from server by UUID to get the ID
+	cfg, err := s.configRepo.GetByUUID(change.EntityUUID)
+	if err != nil {
+		// Already deleted or not found, consider it successful
+		slog.Warn("configuration not found on server, considering delete successful", "uuid", change.EntityUUID)
+		return nil
+	}
+
+	// Delete from server
+	if err := s.configRepo.Delete(cfg.ID); err != nil {
+		return fmt.Errorf("deleting configuration from server: %w", err)
+	}
+
+	slog.Info("configuration deleted from server", "uuid", change.EntityUUID)
+	return nil
+}
--- a/internal/services/sync/worker.go
+++ b/internal/services/sync/worker.go
@@ -0,0 +1,95 @@
+package sync
+
+import (
+	"context"
+	"log/slog"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+// Worker performs background synchronization at regular intervals
+type Worker struct {
+	service  *Service
+	db       *gorm.DB
+	interval time.Duration
+	logger   *slog.Logger
+	stopCh   chan struct{}
+}
+
+// NewWorker creates a new background sync worker
+func NewWorker(service *Service, db *gorm.DB, interval time.Duration) *Worker {
+	return &Worker{
+		service:  service,
+		db:       db,
+		interval: interval,
+		logger:   slog.Default(),
+		stopCh:   make(chan struct{}),
+	}
+}
+
+// isOnline checks if the database connection is available
+func (w *Worker) isOnline() bool {
+	sqlDB, err := w.db.DB()
+	if err != nil {
+		return false
+	}
+	return sqlDB.Ping() == nil
+}
+
+// Start begins the background sync loop in a goroutine
+func (w *Worker) Start(ctx context.Context) {
+	w.logger.Info("starting background sync worker", "interval", w.interval)
+
+	ticker := time.NewTicker(w.interval)
+	defer ticker.Stop()
+
+	// Run once immediately
+	w.runSync()
+
+	for {
+		select {
+		case <-ctx.Done():
+			w.logger.Info("background sync worker stopped by context")
+			return
+		case <-w.stopCh:
+			w.logger.Info("background sync worker stopped")
+			return
+		case <-ticker.C:
+			w.runSync()
+		}
+	}
+}
+
+// Stop gracefully stops the worker
+func (w *Worker) Stop() {
+	w.logger.Info("stopping background sync worker")
+	close(w.stopCh)
+}
+
+// runSync performs a single sync iteration
+func (w *Worker) runSync() {
+	// Check if online
+	if !w.isOnline() {
+		w.logger.Debug("offline, skipping background sync")
+		return
+	}
+
+	w.logger.Debug("running background sync")
+
+	// Push pending changes first
+	pushed, err := w.service.PushPendingChanges()
+	if err != nil {
+		w.logger.Warn("failed to push pending changes", "error", err)
+	} else if pushed > 0 {
+		w.logger.Info("pushed pending changes", "count", pushed)
+	}
+
+	// Then check for new pricelists
+	err = w.service.SyncPricelistsIfNeeded()
+	if err != nil {
+		w.logger.Warn("failed to sync pricelists", "error", err)
+	}
+
+	w.logger.Debug("background sync completed")
+}