import type { Message } from "../types.ts";

/**
 * For harnesses that cannot be seeded with prior messages: prefix the new
 * input with the conversation so far as a transcript.
 */
export function withTranscript(history: Message[], input: string): string {
  const turns = history.filter((m) => (m.role === "user" || m.role === "assistant") && m.content);
  if (turns.length === 0) return input;
  const transcript = turns.map((m) => `${m.role === "user" ? "User" : "Assistant"}: ${m.content}`).join("\n\n");
  return `<conversation_so_far>\n${transcript}\n</conversation_so_far>\n\n${input}`;
}