// redis's provisioner — the adapter that makes redis a provider of the mesh `redis-cache`
// interface. The reconcile loop, the contributions file, and reading the mesh's minted password are
// the sdk harness's; this writes only the per-service half: how redis creates and removes a
// per-consumer cache (novox/hq ADR 0039/0040/0048).
//
// The `redis-cache` interface: a consumer connects as `as` with the password the mesh minted, and
// stores its keys under `<as>:*`, isolated from every other consumer by an ACL user scoped to
// exactly that prefix.
//
// **The login and password are the mesh's, not the provisioner's (ADR 0048).** The mesh derives the
// login and hands it to both ends so they agree, and mints the password and delivers a copy to each.
// redis creates exactly that login with exactly that password — a name or password the provisioner
// invented is one the consumer could never present.

import { runProvisioner, type Provision } from "@novox/mesh-sdk/provisioner";
import { emit } from "@novox/mesh-sdk/events";
import { RedisClient } from "../client.js";

const redis = RedisClient.fromEnv();

/** Emit a lifecycle event without letting a broker hiccup fail the provisioning itself. */
async function announce(type: string, body: Record<string, string>): Promise<void> {
  try {
    await emit(type, body);
  } catch (err) {
    console.error(`[provisioner:redis-cache] emit ${type} failed: ${err}`);
  }
}

runProvisioner("redis-cache", {
  async create(p: Provision): Promise<void> {
    // The keyspace is scoped to the consumer's own login, so one cannot read another's keys.
    const keyspacePrefix = p.as;
    await redis.createAclUser(p.as, p.password, keyspacePrefix);
    await announce("module.redis.cache.provisioned", {
      consumer: p.consumer ?? "",
      username: p.as,
      keyspacePrefix,
    });
  },

  async remove(p: { as: string }): Promise<void> {
    await redis.deleteAclUser(p.as);
    await announce("module.redis.cache.deprovisioned", { username: p.as });
  },

  // This server keeps its ACL users in memory only, so a restart of it forgets every consumer while
  // this provisioner keeps running. Asked every minute, so a forgotten user is made again instead
  // of every consumer failing to authenticate in silence (novox/hq issue 120).
  async holds(p: Provision): Promise<boolean> {
    return redis.holdsAclUser(p.as, p.password);
  },
});