import type { UIMessage } from "ai";

type MessagePart = UIMessage["parts"][number];
type ReasoningPart = Extract<MessagePart, { type: "reasoning" }>;

export function getTextContent(parts: MessagePart[]): string {
  return parts
    .filter((p) => p.type === "text")
    .map((p) => p.text || "")
    .join("");
}

export function getReasoningPart(parts: MessagePart[]): ReasoningPart | undefined {
  return parts.find((p): p is ReasoningPart => p.type === "reasoning");
}