import { getRedis } from "./redis";
import { sessionTtlSeconds } from "./session-ttl";

export type SessionPayload = {
  userId: number;
  sessionVersion: number;
  createdAt: string;
};

const sessionKey = (id: string) => `sess:${id}`;

export async function createSession(
  sessionId: string,
  payload: SessionPayload,
): Promise<void> {
  const redis = getRedis();
  const ttl = sessionTtlSeconds();
  await redis.set(sessionKey(sessionId), JSON.stringify(payload), "EX", ttl);
}

export async function readSession(
  sessionId: string,
): Promise<SessionPayload | null> {
  const redis = getRedis();
  const raw = await redis.get(sessionKey(sessionId));
  if (!raw) return null;
  try {
    return JSON.parse(raw) as SessionPayload;
  } catch {
    return null;
  }
}

export async function deleteSession(sessionId: string): Promise<void> {
  const redis = getRedis();
  await redis.del(sessionKey(sessionId));
}