deerflow-code/frontend-web/src/core/threads/utils.ts

import { useContext } from "react";
import type { Message } from "@langchain/langgraph-sdk";

import { RouteBaseContext } from "@/core/route-base";
import type { AgentThread, AgentThreadContext } from "./types";

type ThreadAgentRef = Pick<AgentThreadContext, "agent_id" | "agent_name">;

type ThreadRouteTarget =
  | string
  | {
      thread_id: string;
      context?: ThreadAgentRef | null;
      metadata?: Record<string, unknown> | null;
    };

function pickAgentRef(
  context: ThreadAgentRef | null | undefined,
  metadata: Record<string, unknown> | null | undefined,
): string | undefined {
  if (context?.agent_id) return context.agent_id;
  if (context?.agent_name) return context.agent_name;
  const metaId = metadata?.agent_id;
  if (typeof metaId === "string" && metaId) return metaId;
  const metaName = metadata?.agent_name;
  if (typeof metaName === "string" && metaName) return metaName;
  return undefined;
}

export function pathOfThread(
  thread: ThreadRouteTarget,
  context?: ThreadAgentRef | null,
  base = "/page/workspace",
) {
  const threadId = typeof thread === "string" ? thread : thread.thread_id;
  const agentRef =
    typeof thread === "string"
      ? pickAgentRef(context, null)
      : pickAgentRef(thread.context, thread.metadata);

  return agentRef
    ? `${base}/agents/${encodeURIComponent(agentRef)}/chats/${threadId}`
    : `${base}/chats/${threadId}`;
}

export function usePathOfThread() {
  const base = useContext(RouteBaseContext);
  return (thread: ThreadRouteTarget, context?: ThreadAgentRef | null) =>
    pathOfThread(thread, context, base);
}

export function textOfMessage(message: Message) {
  if (typeof message.content === "string") {
    return message.content;
  } else if (Array.isArray(message.content)) {
    for (const part of message.content) {
      if (part.type === "text") {
        return part.text;
      }
    }
  }
  return null;
}

export function titleOfThread(thread: AgentThread, fallback = "Untitled") {
  const title = thread.values?.title;
  if (title) return title;

  // No title yet (e.g. the very first turn is still streaming, or the backend
  // title pass hasn't finished). Derive a sensible display title from the first
  // user message so the user never sees a bare "Untitled" placeholder.
  const messages = thread.values?.messages;
  if (Array.isArray(messages)) {
    const firstHuman = messages.find((m) => m.type === "human");
    const text = firstHuman ? textOfMessage(firstHuman)?.trim() : null;
    if (text) {
      return text.length > 50 ? `${text.slice(0, 50).trimEnd()}…` : text;
    }
  }

  return fallback;
}

export function sanitizeThreadTitleForDisplay(title: string | null | undefined) {
  if (!title) return "Untitled";

  const cleaned = title
    .replace(/<\/?[^>\n]+>/g, " ")
    .replace(/<[^>\n]*$/g, " ")
    .replace(/\s+/g, " ")
    .trim();

  return cleaned || "Untitled";
}