refactor: SearchEngine interface, remove nilable qdrantStore

fts5.go

@@ -0,0 +1,23 @@
+package main
+
+import "context"
+
+type fts5Engine struct {
+	sqlite *sqliteStore
+}
+
+func newFTS5Engine(sqlite *sqliteStore) *fts5Engine {
+	return &fts5Engine{sqlite: sqlite}
+}
+
+func (e *fts5Engine) Index(ctx context.Context, id, _ int64, _ int, note string) error {
+	return e.sqlite.indexFTS(ctx, id, note)
+}
+
+func (e *fts5Engine) Delete(ctx context.Context, id, _ int64) error {
+	return e.sqlite.deleteFTS(ctx, id)
+}
+
+func (e *fts5Engine) Search(ctx context.Context, query string, limit uint64) ([]searchResult, error) {
+	return e.sqlite.searchFTS(ctx, query, limit)
+}

main.go

@@ -30,43 +30,10 @@ func main() {
 	}
 	defer logger.Sync()
 
-	qdrantURL := os.Getenv("QDRANT_URL")
-	openAIKey := requireEnv(logger, "OPENAI_API_KEY")
 	token := requireEnv(logger, "MCP_TOKEN")
-	embeddingModel := os.Getenv("EMBEDDING_MODEL")
-	embeddingBaseURL := os.Getenv("EMBEDDING_BASE_URL")
+	openAIKey := requireEnv(logger, "OPENAI_API_KEY")
 	port := envOrDefault("PORT", "8080")
 
-	qdrantPort := 6334
-	if p, err := strconv.Atoi(envOrDefault("QDRANT_PORT", "6334")); err == nil {
-		qdrantPort = p
-	}
-	qdrantAPIKey := os.Getenv("QDRANT_API_KEY")
-	qdrantTLS := os.Getenv("QDRANT_TLS") == "true"
-
-	var qdrantStr *qdrantStore
-	if qdrantURL != "" {
-		qdrantClient, err := qdrant.NewClient(&qdrant.Config{
-			Host:   qdrantURL,
-			Port:   qdrantPort,
-			APIKey: qdrantAPIKey,
-			UseTLS: qdrantTLS,
-		})
-		if err != nil {
-			logger.Fatal("failed to create qdrant client", zap.Error(err))
-		}
-		defer qdrantClient.Close()
-
-		emb := newEmbedder(openAIKey, embeddingModel, embeddingBaseURL)
-		qdrantStr = newQdrantStore(qdrantClient, emb)
-
-		if err := qdrantStr.ensureCollection(context.Background()); err != nil {
-			logger.Fatal("failed to ensure collection", zap.Error(err))
-		}
-	} else {
-		logger.Warn("QDRANT_URL not set, using SQLite FTS5 for search")
-	}
-
 	sqlitePath := envOrDefault("SQLITE_PATH", "flashcard.db")
 	sqliteStore, err := newSqliteStore(sqlitePath)
 	if err != nil {
@@ -74,6 +41,8 @@ func main() {
 	}
 	defer sqliteStore.close()
 
+	searchEngine := createSearchEngine(logger, sqliteStore, openAIKey)
+
 	mcpServer := server.NewMCPServer(
 		"flashcard-mcp",
 		version,
@@ -81,10 +50,10 @@ func main() {
 		server.WithLogging(),
 	)
 
-	registerStoreFlashcard(mcpServer, sqliteStore, qdrantStr, logger)
-	registerSearchFlashcard(mcpServer, sqliteStore, qdrantStr)
-	registerUpdateFlashcard(mcpServer, sqliteStore, qdrantStr, logger)
-	registerDeleteFlashcard(mcpServer, sqliteStore, qdrantStr, logger)
+	registerStoreFlashcard(mcpServer, sqliteStore, searchEngine, logger)
+	registerSearchFlashcard(mcpServer, searchEngine)
+	registerUpdateFlashcard(mcpServer, sqliteStore, searchEngine, logger)
+	registerDeleteFlashcard(mcpServer, sqliteStore, searchEngine, logger)
 
 	streamableServer := server.NewStreamableHTTPServer(mcpServer)
 
@@ -128,7 +97,44 @@ func main() {
 	}
 }
 
-func registerStoreFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.Logger) {
+func createSearchEngine(logger *zap.Logger, sqliteStore *sqliteStore, openAIKey string) SearchEngine {
+	qdrantURL := os.Getenv("QDRANT_URL")
+	if qdrantURL == "" {
+		logger.Warn("QDRANT_URL not set, using SQLite FTS5 for search")
+		return newFTS5Engine(sqliteStore)
+	}
+
+	embeddingModel := os.Getenv("EMBEDDING_MODEL")
+	embeddingBaseURL := os.Getenv("EMBEDDING_BASE_URL")
+
+	qdrantPort := 6334
+	if p, err := strconv.Atoi(envOrDefault("QDRANT_PORT", "6334")); err == nil {
+		qdrantPort = p
+	}
+	qdrantAPIKey := os.Getenv("QDRANT_API_KEY")
+	qdrantTLS := os.Getenv("QDRANT_TLS") == "true"
+
+	client, err := qdrant.NewClient(&qdrant.Config{
+		Host:   qdrantURL,
+		Port:   qdrantPort,
+		APIKey: qdrantAPIKey,
+		UseTLS: qdrantTLS,
+	})
+	if err != nil {
+		logger.Fatal("failed to create qdrant client", zap.Error(err))
+	}
+
+	emb := newEmbedder(openAIKey, embeddingModel, embeddingBaseURL)
+	store := newQdrantStore(client, emb, sqliteStore, logger)
+
+	if err := store.ensureCollection(context.Background()); err != nil {
+		logger.Fatal("failed to ensure collection", zap.Error(err))
+	}
+
+	return store
+}
+
+func registerStoreFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, engine SearchEngine, logger *zap.Logger) {
 	mcpServer.AddTool(
 		mcp.NewTool("store_flashcard",
 			mcp.WithDescription("Store a flashcard for later retrieval. Use this to persist useful information discovered during a session."),
@@ -155,11 +161,11 @@ func registerStoreFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, qd
 				mcp.Description("Optional context — what triggered this"),
 			),
 		),
-		handleStoreFlashcard(sqlite, qdrant, logger),
+		handleStoreFlashcard(sqlite, engine, logger),
 	)
 }
 
-func registerSearchFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, qdrant *qdrantStore) {
+func registerSearchFlashcard(mcpServer *server.MCPServer, engine SearchEngine) {
 	mcpServer.AddTool(
 		mcp.NewTool("search_flashcard",
 			mcp.WithDescription("Search previously stored flashcards using semantic search. Returns the most relevant entries for the given query."),
@@ -171,11 +177,11 @@ func registerSearchFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, q
 				mcp.Description("Maximum number of results to return (default: 5)"),
 			),
 		),
-		handleSearchFlashcard(sqlite, qdrant),
+		handleSearchFlashcard(engine),
 	)
 }
 
-func registerUpdateFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.Logger) {
+func registerUpdateFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, engine SearchEngine, logger *zap.Logger) {
 	mcpServer.AddTool(
 		mcp.NewTool("update_flashcard",
 			mcp.WithDescription("Update an existing flashcard. Creates a new version while preserving history."),
@@ -202,11 +208,11 @@ func registerUpdateFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, q
 				mcp.Description("Optional context — what triggered this"),
 			),
 		),
-		handleUpdateFlashcard(sqlite, qdrant, logger),
+		handleUpdateFlashcard(sqlite, engine, logger),
 	)
 }
 
-func handleUpdateFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.Logger) server.ToolHandlerFunc {
+func handleUpdateFlashcard(sqlite *sqliteStore, engine SearchEngine, logger *zap.Logger) server.ToolHandlerFunc {
 	return func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 		args, ok := request.Params.Arguments.(map[string]any)
 		if !ok {
@@ -258,16 +264,11 @@ func handleUpdateFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap
 			return mcp.NewToolResultError(fmt.Sprintf("failed to persist update: %v", err)), nil
 		}
 
-		if err := sqlite.deleteFTS(ctx, latest.ID); err != nil {
-			logger.Warn("fts delete failed", zap.Int64("id", latest.ID), zap.Error(err))
+		if err := engine.Delete(ctx, latest.ID, publicID); err != nil {
+			logger.Warn("search engine delete failed", zap.Int64("id", latest.ID), zap.Error(err))
 		}
-		if err := sqlite.indexFTS(ctx, id, note); err != nil {
-			return mcp.NewToolResultError(fmt.Sprintf("fts index failed: %v", err)), nil
-		}
-		if qdrant != nil {
-			if err := qdrant.index(ctx, id, publicID, version, note); err != nil {
-				logger.Warn("qdrant index failed (entry in sqlite)", zap.Int64("id", id), zap.Error(err))
-			}
+		if err := engine.Index(ctx, id, publicID, version, note); err != nil {
+			return mcp.NewToolResultError(fmt.Sprintf("search engine index failed: %v", err)), nil
 		}
 
 		entry, err := sqlite.getByID(ctx, id)
@@ -284,20 +285,20 @@ func handleUpdateFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap
 	}
 }
 
-func registerDeleteFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.Logger) {
+func registerDeleteFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, engine SearchEngine, logger *zap.Logger) {
 	mcpServer.AddTool(
 		mcp.NewTool("delete_flashcard",
-			mcp.WithDescription("Delete a flashcard. Creates a tombstone version and removes it from the vector index."),
+			mcp.WithDescription("Delete a flashcard. Creates a tombstone version and removes it from the search index."),
 			mcp.WithNumber("public_id",
 				mcp.Required(),
 				mcp.Description("Public identifier of the flashcard to delete"),
 			),
 		),
-		handleDeleteFlashcard(sqlite, qdrant, logger),
+		handleDeleteFlashcard(sqlite, engine, logger),
 	)
 }
 
-func handleDeleteFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.Logger) server.ToolHandlerFunc {
+func handleDeleteFlashcard(sqlite *sqliteStore, engine SearchEngine, logger *zap.Logger) server.ToolHandlerFunc {
 	return func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 		args, ok := request.Params.Arguments.(map[string]any)
 		if !ok {
@@ -324,20 +325,15 @@ func handleDeleteFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap
 			return mcp.NewToolResultError(fmt.Sprintf("failed to tombstone: %v", err)), nil
 		}
 
-		if err := sqlite.deleteFTS(ctx, latest.ID); err != nil {
-			logger.Warn("fts delete failed", zap.Int64("id", latest.ID), zap.Error(err))
-		}
-		if qdrant != nil {
-			if err := qdrant.delete(ctx, publicID); err != nil {
-				logger.Warn("qdrant delete failed (tombstone in sqlite)", zap.Int64("public_id", publicID), zap.Error(err))
-			}
+		if err := engine.Delete(ctx, latest.ID, publicID); err != nil {
+			logger.Warn("search engine delete failed", zap.Int64("id", latest.ID), zap.Error(err))
 		}
 
 		return mcp.NewToolResultText(fmt.Sprintf("flashcard %d deleted", publicID)), nil
 	}
 }
 
-func handleStoreFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.Logger) server.ToolHandlerFunc {
+func handleStoreFlashcard(sqlite *sqliteStore, engine SearchEngine, logger *zap.Logger) server.ToolHandlerFunc {
 	return func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 		args, ok := request.Params.Arguments.(map[string]any)
 		if !ok {
@@ -364,13 +360,8 @@ func handleStoreFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.
 		if publicID == 0 {
 			publicID = id
 		}
-		if err := sqlite.indexFTS(ctx, id, note); err != nil {
-			return mcp.NewToolResultError(fmt.Sprintf("fts index failed: %v", err)), nil
-		}
-		if qdrant != nil {
-			if err := qdrant.index(ctx, id, publicID, 1, note); err != nil {
-				logger.Warn("qdrant index failed (entry in sqlite)", zap.Int64("id", id), zap.Error(err))
-			}
+		if err := engine.Index(ctx, id, publicID, 1, note); err != nil {
+			return mcp.NewToolResultError(fmt.Sprintf("search engine index failed: %v", err)), nil
 		}
 
 		entry, err := sqlite.getByID(ctx, id)
@@ -387,7 +378,7 @@ func handleStoreFlashcard(sqlite *sqliteStore, qdrant *qdrantStore, logger *zap.
 	}
 }
 
-func handleSearchFlashcard(sqlite *sqliteStore, qdrant *qdrantStore) server.ToolHandlerFunc {
+func handleSearchFlashcard(engine SearchEngine) server.ToolHandlerFunc {
 	return func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 		args, ok := request.Params.Arguments.(map[string]any)
 		if !ok {
@@ -411,23 +402,9 @@ func handleSearchFlashcard(sqlite *sqliteStore, qdrant *qdrantStore) server.Tool
 			}
 		}
 
-		var results []searchResult
-		var err error
-		if qdrant != nil {
-			results, err = qdrant.search(ctx, query, limit)
-			if err != nil {
-				return mcp.NewToolResultError(fmt.Sprintf("search failed: %v", err)), nil
-			}
-			for i, r := range results {
-				if cached, err := sqlite.getByID(ctx, r.Entry.ID); err == nil && cached != nil {
-					results[i].Entry = *cached
-				}
-			}
-		} else {
-			results, err = sqlite.searchFTS(ctx, query, limit)
-			if err != nil {
-				return mcp.NewToolResultError(fmt.Sprintf("search failed: %v", err)), nil
-			}
+		results, err := engine.Search(ctx, query, limit)
+		if err != nil {
+			return mcp.NewToolResultError(fmt.Sprintf("search failed: %v", err)), nil
 		}
 
 		output, err := json.MarshalIndent(results, "", "  ")

qdrant.go

@@ -6,36 +6,20 @@ import (
 	"strconv"
 
 	"github.com/qdrant/go-client/qdrant"
+	"go.uber.org/zap"
 )
 
 const collectionName = "flashcard"
 
-type entry struct {
-	ID        int64    `json:"_id"`
-	PublicID  int64    `json:"public_id"`
-	Version   int      `json:"version"`
-	Note      string   `json:"note"`
-	Repos     []string `json:"repos,omitempty"`
-	Host      string   `json:"host,omitempty"`
-	Tags      []string `json:"tags,omitempty"`
-	User      string   `json:"user,omitempty"`
-	Context         string   `json:"context,omitempty"`
-	DeleteTimestamp string   `json:"delete_timestamp,omitempty"`
-	Created         string   `json:"created"`
-}
-
-type searchResult struct {
-	Entry entry   `json:",inline"`
-	Score float32 `json:"score"`
-}
-
 type qdrantStore struct {
 	client   *qdrant.Client
 	embedder *embedder
+	sqlite   *sqliteStore
+	logger   *zap.Logger
 }
 
-func newQdrantStore(client *qdrant.Client, embedder *embedder) *qdrantStore {
-	return &qdrantStore{client: client, embedder: embedder}
+func newQdrantStore(client *qdrant.Client, embedder *embedder, sqlite *sqliteStore, logger *zap.Logger) *qdrantStore {
+	return &qdrantStore{client: client, embedder: embedder, sqlite: sqlite, logger: logger}
 }
 
 func (s *qdrantStore) ensureCollection(ctx context.Context) error {
@@ -61,7 +45,7 @@ func (s *qdrantStore) ensureCollection(ctx context.Context) error {
 	return nil
 }
 
-func (s *qdrantStore) index(ctx context.Context, id, publicID int64, version int, note string) error {
+func (s *qdrantStore) Index(ctx context.Context, id, publicID int64, version int, note string) error {
 	vec, err := s.embedder.embedText(ctx, note)
 	if err != nil {
 		return fmt.Errorf("embed text: %w", err)
@@ -85,13 +69,12 @@ func (s *qdrantStore) index(ctx context.Context, id, publicID int64, version int
 		},
 	})
 	if err != nil {
-		return fmt.Errorf("upsert point: %w", err)
+		s.logger.Warn("qdrant index failed (entry in sqlite)", zap.Int64("id", id), zap.Error(err))
 	}
-
 	return nil
 }
 
-func (s *qdrantStore) delete(ctx context.Context, publicID int64) error {
+func (s *qdrantStore) Delete(ctx context.Context, id, publicID int64) error {
 	wait := true
 	_, err := s.client.Delete(ctx, &qdrant.DeletePoints{
 		CollectionName: collectionName,
@@ -101,12 +84,12 @@ func (s *qdrantStore) delete(ctx context.Context, publicID int64) error {
 		),
 	})
 	if err != nil {
-		return fmt.Errorf("delete point: %w", err)
+		s.logger.Warn("qdrant delete failed (tombstone in sqlite)", zap.Int64("public_id", publicID), zap.Error(err))
 	}
 	return nil
 }
 
-func (s *qdrantStore) search(ctx context.Context, query string, limit uint64) ([]searchResult, error) {
+func (s *qdrantStore) Search(ctx context.Context, query string, limit uint64) ([]searchResult, error) {
 	vec, err := s.embedder.embedText(ctx, query)
 	if err != nil {
 		return nil, fmt.Errorf("embed query: %w", err)
@@ -140,6 +123,10 @@ func (s *qdrantStore) search(ctx context.Context, query string, limit uint64) ([
 			}
 		}
 
+		if cached, err := s.sqlite.getByID(ctx, r.Entry.ID); err == nil && cached != nil {
+			r.Entry = *cached
+		}
+
 		searchResults = append(searchResults, r)
 	}
 

search.go

@@ -0,0 +1,9 @@
+package main
+
+import "context"
+
+type SearchEngine interface {
+	Index(ctx context.Context, id, publicID int64, version int, note string) error
+	Delete(ctx context.Context, id, publicID int64) error
+	Search(ctx context.Context, query string, limit uint64) ([]searchResult, error)
+}

types.go

@@ -0,0 +1,20 @@
+package main
+
+type entry struct {
+	ID              int64    `json:"_id"`
+	PublicID        int64    `json:"public_id"`
+	Version         int      `json:"version"`
+	Note            string   `json:"note"`
+	Repos           []string `json:"repos,omitempty"`
+	Host            string   `json:"host,omitempty"`
+	Tags            []string `json:"tags,omitempty"`
+	User            string   `json:"user,omitempty"`
+	Context         string   `json:"context,omitempty"`
+	DeleteTimestamp string   `json:"delete_timestamp,omitempty"`
+	Created         string   `json:"created"`
+}
+
+type searchResult struct {
+	Entry entry   `json:",inline"`
+	Score float32 `json:"score"`
+}