feat: add support for SCIM provisioning (#1182)

backend/internal/service/scim_scheduler_service.go

@@ -0,0 +1,136 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"sync"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+// ScimSchedulerService schedules and triggers periodic synchronization
+// of SCIM service providers. Each provider is tracked independently,
+// and sync operations are run at or after their scheduled time.
+type ScimSchedulerService struct {
+	scimService      *ScimService
+	providerSyncTime map[string]time.Time
+	mu               sync.RWMutex
+}
+
+func NewScimSchedulerService(ctx context.Context, scimService *ScimService) (*ScimSchedulerService, error) {
+	s := &ScimSchedulerService{
+		scimService:      scimService,
+		providerSyncTime: make(map[string]time.Time),
+	}
+
+	err := s.start(ctx)
+	return s, err
+}
+
+// ScheduleSync forces the given provider to be synced soon by
+// moving its next scheduled time to 5 minutes from now.
+func (s *ScimSchedulerService) ScheduleSync(providerID string) {
+	s.setSyncTime(providerID, 5*time.Minute)
+}
+
+// start initializes the scheduler and begins the synchronization loop.
+// Syncs happen every hour by default, but ScheduleSync can be called to schedule a sync sooner.
+func (s *ScimSchedulerService) start(ctx context.Context) error {
+	if err := s.refreshProviders(ctx); err != nil {
+		return err
+	}
+
+	go func() {
+		const (
+			syncCheckInterval    = 5 * time.Second
+			providerRefreshDelay = time.Minute
+		)
+
+		ticker := time.NewTicker(syncCheckInterval)
+		defer ticker.Stop()
+		lastProviderRefresh := time.Now()
+
+		for {
+			select {
+			case <-ctx.Done():
+				return
+				// Runs every 5 seconds to check if any provider is due for sync
+			case <-ticker.C:
+				now := time.Now()
+				if now.Sub(lastProviderRefresh) >= providerRefreshDelay {
+					err := s.refreshProviders(ctx)
+					if err != nil {
+						slog.Error("Error refreshing SCIM service providers",
+							slog.Any("error", err),
+						)
+					} else {
+						lastProviderRefresh = now
+					}
+				}
+
+				var due []string
+				s.mu.RLock()
+				for providerID, syncTime := range s.providerSyncTime {
+					if !syncTime.After(now) {
+						due = append(due, providerID)
+					}
+				}
+				s.mu.RUnlock()
+
+				s.syncProviders(ctx, due)
+
+			}
+		}
+	}()
+
+	return nil
+}
+
+func (s *ScimSchedulerService) refreshProviders(ctx context.Context) error {
+	providers, err := s.scimService.ListServiceProviders(ctx)
+	if err != nil {
+		return err
+	}
+
+	inAHour := time.Now().Add(time.Hour)
+
+	s.mu.Lock()
+	for _, provider := range providers {
+		if _, exists := s.providerSyncTime[provider.ID]; !exists {
+			s.providerSyncTime[provider.ID] = inAHour
+		}
+	}
+	s.mu.Unlock()
+
+	return nil
+}
+
+func (s *ScimSchedulerService) syncProviders(ctx context.Context, providerIDs []string) {
+	for _, providerID := range providerIDs {
+		err := s.scimService.SyncServiceProvider(ctx, providerID)
+		if err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				// Remove the provider from the schedule if it no longer exists
+				s.mu.Lock()
+				delete(s.providerSyncTime, providerID)
+				s.mu.Unlock()
+			} else {
+				slog.Error("Error syncing SCIM client",
+					slog.String("provider_id", providerID),
+					slog.Any("error", err),
+				)
+			}
+			continue
+		}
+		// A successful sync schedules the next sync in an hour
+		s.setSyncTime(providerID, time.Hour)
+	}
+}
+
+func (s *ScimSchedulerService) setSyncTime(providerID string, t time.Duration) {
+	s.mu.Lock()
+	s.providerSyncTime[providerID] = time.Now().Add(t)
+	s.mu.Unlock()
+}