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

export const STATUS_EVENT_HISTORY_LIMIT = 100;
const OMITTED_STATUS_EVENTS_OP = "status-events-omitted";

function trimStatusHistory(events: EvalStatusEvent[]): void {
  if (events.length <= STATUS_EVENT_HISTORY_LIMIT) {
    return;
  }

  const first = events[0];
  if (
    first?.op === OMITTED_STATUS_EVENTS_OP &&
    typeof first.count === "number"
  ) {
    const removeCount = events.length - STATUS_EVENT_HISTORY_LIMIT;
    events.splice(1, removeCount);
    events[0] = {
      op: OMITTED_STATUS_EVENTS_OP,
      count: first.count + removeCount,
    };
    return;
  }

  const removeCount = events.length - STATUS_EVENT_HISTORY_LIMIT + 1;
  events.splice(0, removeCount, {
    op: OMITTED_STATUS_EVENTS_OP,
    count: removeCount,
  });
}

export function upsertStatusEvent(
  events: EvalStatusEvent[],
  event: EvalStatusEvent
): void {
  if (event.op === "agent" && typeof event.id === "string") {
    const index = events.findIndex(
      (candidate) => candidate.op === "agent" && candidate.id === event.id
    );
    if (index >= 0) {
      events[index] = event;
      trimStatusHistory(events);
      return;
    }
  }
  events.push(event);
  trimStatusHistory(events);
}