feat: notify document updates over websocket

apps/server/internal/docs/service.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 
 	"github.com/tim/md-hub-secure/apps/server/internal/markdown"
 	"github.com/tim/md-hub-secure/apps/server/internal/store"
@@ -21,6 +22,15 @@ type Service struct {
 	renderer  *markdown.Renderer
 	repo      *Repository
 	logger    *slog.Logger
+	mu        sync.Mutex
+	onChange  func(DocumentChange)
+}
+
+type DocumentChange struct {
+	Path         string `json:"path"`
+	Title        string `json:"title"`
+	Hash         string `json:"hash"`
+	PreviousHash string `json:"previousHash,omitempty"`
 }
 
 type Page struct {
@@ -41,27 +51,56 @@ func NewService(sourceDir string, store *store.ContentStore, renderer *markdown.
 	}
 }
 
-func (s *Service) SyncSourceDir(ctx context.Context) error {
-	return filepath.WalkDir(s.sourceDir, func(path string, entry fs.DirEntry, err error) error {
+func (s *Service) OnChange(callback func(DocumentChange)) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.onChange = callback
+}
+
+func (s *Service) SyncSourceDir(ctx context.Context) ([]DocumentChange, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	var changes []DocumentChange
+	err := filepath.WalkDir(s.sourceDir, func(path string, entry fs.DirEntry, err error) error {
 		if err != nil {
 			return err
 		}
 		if entry.IsDir() || filepath.Ext(path) != ".md" {
 			return nil
 		}
-		return s.syncFile(ctx, path)
+
+		change, err := s.syncFile(ctx, path)
+		if err != nil {
+			return err
+		}
+		if change != nil {
+			changes = append(changes, *change)
+		}
+		return nil
 	})
+	if err != nil {
+		return nil, err
+	}
+
+	if s.onChange != nil {
+		for _, change := range changes {
+			s.onChange(change)
+		}
+	}
+
+	return changes, nil
 }
 
 func (s *Service) ListDocuments(ctx context.Context) ([]DocumentRecord, error) {
-	if err := s.SyncSourceDir(ctx); err != nil {
+	if _, err := s.SyncSourceDir(ctx); err != nil {
 		return nil, err
 	}
 	return s.repo.ListDocuments(ctx)
 }
 
 func (s *Service) LoadPage(ctx context.Context, requestPath string) (*Page, error) {
-	if err := s.SyncSourceDir(ctx); err != nil {
+	if _, err := s.SyncSourceDir(ctx); err != nil {
 		return nil, err
 	}
 
@@ -101,31 +140,31 @@ func normalizeRequestPath(path string) string {
 	return path
 }
 
-func (s *Service) syncFile(ctx context.Context, path string) error {
+func (s *Service) syncFile(ctx context.Context, path string) (*DocumentChange, error) {
 	content, err := os.ReadFile(path)
 	if err != nil {
-		return fmt.Errorf("read content file %s: %w", path, err)
+		return nil, fmt.Errorf("read content file %s: %w", path, err)
 	}
 
 	rendered, err := s.renderer.Render(content)
 	if err != nil {
-		return fmt.Errorf("render content file %s: %w", path, err)
+		return nil, fmt.Errorf("render content file %s: %w", path, err)
 	}
 
 	record, err := s.store.PutBytes(content)
 	if err != nil {
-		return fmt.Errorf("store content file %s: %w", path, err)
+		return nil, fmt.Errorf("store content file %s: %w", path, err)
 	}
 
 	relative, err := filepath.Rel(s.sourceDir, path)
 	if err != nil {
-		return fmt.Errorf("compute relative path %s: %w", path, err)
+		return nil, fmt.Errorf("compute relative path %s: %w", path, err)
 	}
 	relative = filepath.ToSlash(relative)
 
 	existing, err := s.repo.GetDocumentByPath(ctx, relative)
 	if err != nil && !errors.Is(err, sql.ErrNoRows) {
-		return err
+		return nil, err
 	}
 
 	previousHash := ""
@@ -134,7 +173,7 @@ func (s *Service) syncFile(ctx context.Context, path string) error {
 		previousHash = existing.CurrentHash
 		documentID = existing.ID
 		if existing.CurrentHash == record.Hash {
-			return nil
+			return nil, nil
 		}
 	}
 
@@ -146,9 +185,14 @@ func (s *Service) syncFile(ctx context.Context, path string) error {
 		PreviousHash: previousHash,
 		Tags:         rendered.Tags,
 	}); err != nil {
-		return err
+		return nil, err
 	}
 
 	s.logger.Debug("synced document", "path", relative, "hash", record.Hash)
-	return nil
+	return &DocumentChange{
+		Path:         relative,
+		Title:        rendered.Title,
+		Hash:         record.Hash,
+		PreviousHash: previousHash,
+	}, nil
 }