// postgres's provisioner — the adapter that makes postgres a provider of the mesh
// `postgres-database` 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 postgres creates
// and removes a consumer's database + owning role (novox/hq ADR 0039/0040/0048).
//
// The `postgres-database` interface: a consumer connects to a database it alone owns, as `as` with
// the password the mesh minted.
//
// **The role name and password are the mesh's, not the provisioner's (ADR 0048).** The mesh derives
// the login and hands it to both ends, and mints the password. postgres creates a role and a
// same-named database under exactly that login — a name the consumer cannot learn is a database it
// cannot reach.
//
// The DDL runs through PostgresClient.query(), which is the module's one pending boundary (see
// client.ts).

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

const postgres = PostgresClient.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:postgres-database] emit ${type} failed: ${err}`);
  }
}

runProvisioner("postgres-database", {
  async create(p: Provision): Promise<void> {
    // Database and owning role share the consumer's login, so the consumer owns exactly its own.
    const database = p.as;
    await postgres.createDatabaseAndRole(database, p.as, p.password);
    await announce("module.postgres.database.provisioned", {
      consumer: p.consumer ?? "",
      database,
      user: p.as,
    });
  },

  async remove(p: { as: string }): Promise<void> {
    await postgres.dropDatabaseAndRole(p.as, p.as);
    await announce("module.postgres.database.deprovisioned", { database: p.as });
  },
  // Asked every minute by the harness: whether the backend still holds this consumer exactly as
  // the mesh gave it, so a login lost behind the provisioner's back is made again (novox/hq issue 120).
  async holds(p: Provision): Promise<boolean> {
    return postgres.canConnectAs(p.as, p.as, p.password);
  },
});