feat: add vote_flashcard MCP tool

main.go

@@ -54,6 +54,7 @@ func main() {
 	registerSearchFlashcard(mcpServer, searchEngine)
 	registerUpdateFlashcard(mcpServer, sqliteStore, searchEngine, logger)
 	registerDeleteFlashcard(mcpServer, sqliteStore, searchEngine, logger)
+	registerVoteFlashcard(mcpServer, sqliteStore, logger)
 
 	streamableServer := server.NewStreamableHTTPServer(mcpServer)
 
@@ -334,6 +335,92 @@ func handleDeleteFlashcard(sqlite *sqliteStore, engine SearchEngine, logger *zap
 	}
 }
 
+func registerVoteFlashcard(mcpServer *server.MCPServer, sqlite *sqliteStore, logger *zap.Logger) {
+	mcpServer.AddTool(
+		mcp.NewTool("vote_flashcard",
+			mcp.WithDescription("Vote on a flashcard. Rate it from -3 (worst) to 3 (best). Requires detailed context about who is voting and why."),
+			mcp.WithNumber("public_id",
+				mcp.Required(),
+				mcp.Description("Public identifier of the flashcard to vote on"),
+			),
+			mcp.WithNumber("value",
+				mcp.Required(),
+				mcp.Description("Vote value from -3 to 3"),
+			),
+			mcp.WithString("user",
+				mcp.Required(),
+				mcp.Description("Who is voting"),
+			),
+			mcp.WithString("repo",
+				mcp.Required(),
+				mcp.Description("Repository context for the vote"),
+			),
+			mcp.WithString("message",
+				mcp.Required(),
+				mcp.Description("Justification or context for the vote"),
+			),
+		),
+		handleVoteFlashcard(sqlite, logger),
+	)
+}
+
+func handleVoteFlashcard(sqlite *sqliteStore, 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 {
+			return mcp.NewToolResultError("invalid arguments"), nil
+		}
+
+		publicID := parseInt64(args["public_id"])
+		if publicID == 0 {
+			return mcp.NewToolResultError("public_id is required and must be a positive integer"), nil
+		}
+
+		value := int(parseInt64(args["value"]))
+		if value < -3 || value > 3 {
+			return mcp.NewToolResultError("value must be between -3 and 3"), nil
+		}
+
+		user := parseOptionalString(args["user"])
+		if user == "" {
+			return mcp.NewToolResultError("user is required"), nil
+		}
+
+		repo := parseOptionalString(args["repo"])
+		if repo == "" {
+			return mcp.NewToolResultError("repo is required"), nil
+		}
+
+		message := parseOptionalString(args["message"])
+		if message == "" {
+			return mcp.NewToolResultError("message is required"), nil
+		}
+
+		latest, err := sqlite.getLatestByPublicID(ctx, publicID)
+		if err != nil {
+			return mcp.NewToolResultError(fmt.Sprintf("failed to query: %v", err)), nil
+		}
+		if latest == nil {
+			return mcp.NewToolResultError(fmt.Sprintf("no flashcard found with public_id %d", publicID)), nil
+		}
+		if latest.DeleteTimestamp != "" {
+			return mcp.NewToolResultError(fmt.Sprintf("flashcard %d is deleted", publicID)), nil
+		}
+
+		v, err := sqlite.saveVote(ctx, latest.ID, value, user, repo, message)
+		if err != nil {
+			return mcp.NewToolResultError(fmt.Sprintf("failed to save vote: %v", err)), nil
+		}
+
+		output, err := json.MarshalIndent(v, "", "  ")
+		if err != nil {
+			return mcp.NewToolResultError(fmt.Sprintf("failed to marshal: %v", err)), nil
+		}
+
+		return mcp.NewToolResultText(string(output)), nil
+	}
+}
+
 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)