import type { FeedDependencies } from "./feeds.dependencies.js";

/** TTL-faithful Redis surface, including ownership checks for renewable leases. */
type FeedRedis = FeedDependencies["redis"];
export class MemoryFeedRedis implements FeedRedis {
  readonly entries = new Map<string, { value: string; expiresAt: number }>();
  async get(key: string): Promise<string | null> {
    const entry = this.entries.get(key);
    if (!entry || entry.expiresAt <= Date.now()) { this.entries.delete(key); return null; }
    return entry.value;
  }
  async set(key: string, value: string, options: { nx?: boolean; pxMs?: number } = {}): Promise<boolean> {
    // Atomic NX check: do not yield between reading and writing.
    const entry = this.entries.get(key);
    if (options.nx && entry && entry.expiresAt > Date.now()) return false;
    this.entries.set(key, { value, expiresAt: Date.now() + (options.pxMs ?? 1000) });
    return true;
  }
  async eval(script: string, keys: string[], args: string[]): Promise<number> {
    const key = keys[0] ?? "";
    const entry = this.entries.get(key);
    if (!entry || entry.value !== args[0] || entry.expiresAt <= Date.now()) return 0;
    if (script.includes("PEXPIRE")) entry.expiresAt = Date.now() + Number(args[1]);
    else this.entries.delete(key);
    return 1;
  }
  close(): void {}
}