import type { LoopStateV1 } from "./domain.js";

export const LOOP_STATE_ENTRY = "loop-state";
export interface RestoredLoop { state?: LoopStateV1; unknownVersion?: number; }

export function restoreLoop(entries: readonly unknown[]): RestoredLoop {
  for (let i = entries.length - 1; i >= 0; i--) {
    const entry = entries[i] as { type?: string; customType?: string; data?: unknown };
    if (entry?.type !== "custom" || entry.customType !== LOOP_STATE_ENTRY) continue;
    const data = entry.data as { version?: unknown } | undefined;
    if (!data || typeof data.version !== "number") return { unknownVersion: -1 };
    if (data.version !== 1) return { unknownVersion: data.version };
    return { state: structuredClone(data) as LoopStateV1 };
  }
  return {};
}

export function snapshot(state: LoopStateV1): LoopStateV1 {
  return structuredClone(state);
}