Function PrepareUserMessage

pkg/cli/runner.go:347–374

PrepareUserMessage resolves commands, parses /attach directives, and creates a user message with optional image attachment. This is the common flow for both TUI and CLI modes. PrepareUserMessage resolves commands, parses /attach directives, and creates a user message with optional image attachment.

(ctx context.Context, rt runtime.Runtime, userInput, globalAttachPath string)

// pass the attachment path to session.Session.AddAttachedFile so sub-agents
// inherit the file context.
func PrepareUserMessage(ctx context.Context, rt runtime.Runtime, userInput, globalAttachPath string) (*session.Message, string, error) {
	// Resolve any /command to its prompt text BEFORE switching agents.
	// This ensures the command is looked up in the original agent's command table.
	resolvedContent := runtime.ResolveCommand(ctx, rt, userInput)

	// Switch the active agent if the /command targets a sub-agent.
	// This must happen before the message is added to the session so the
	// next runtime turn runs on the right agent.
	if cmd, _, ok := runtime.LookupCommand(ctx, rt, userInput); ok && cmd.Agent != "" {
		if err := rt.SetCurrentAgent(ctx, cmd.Agent); err != nil {
			slog.WarnContext(ctx, "Failed to switch agent for /command", "agent", cmd.Agent, "error", err)
			return nil, "", fmt.Errorf("switch agent %q: %w", cmd.Agent, err)
		}
		// Agent-only command with no trailing args: switch but send no message.
		if resolvedContent == "" {
			return nil, "", nil
		}
	}

	// Parse for /attach commands in the message
	messageText, attachPath := ParseAttachCommand(resolvedContent)

	// Use either the per-message attachment or the global one
	finalAttachPath := cmp.Or(attachPath, globalAttachPath)

	msg, attachedPath := CreateUserMessageWithAttachment(ctx, messageText, finalAttachPath)
	return msg, attachedPath, nil
}

func ParseAttachCommand(userInput string) (messageText, attachPath string) {
	lines := strings.Split(userInput, "\n")