import type { RunEvent } from "../domain/agent-run";
import type { Conversation } from "../domain/conversation";
import { CoreError } from "../errors/core-error";

export function lastSequence(events: readonly RunEvent[]): number {
  return events.at(-1)?.sequence ?? 0;
}

export function safeErrorMessage(cause: unknown): string {
  return cause instanceof CoreError ? cause.message : "模型服务暂时不可用";
}

export function messagesThroughTrigger(
  conversation: Conversation,
  triggerMessageId: string,
) {
  const index = conversation.messages.findIndex(
    (message) => message.id === triggerMessageId,
  );
  return index < 0
    ? conversation.messages
    : conversation.messages.slice(0, index + 1);
}