# Glue: where the store and one of its readers share a host, the reader waits
# for the unit that writes the cert-auth role it logs in with.
#
# ONE PAIRING PER FILE — the store's reader policy units ← the readers
# they grant, and nothing else. Deleting this leaves every reader as it is on a
# host whose store is remote: it may log in before its role exists, and its own
# retries are what carry it past that.
#
# ⚠️ Gated on BOTH the store and that reader being here. Off the store's host
# there is no local policy unit to order against. On the store's host without
# the reader, setting `systemd.services.<reader>.after` would define a unit
# with no ExecStart, so each gate below restates the one the reader's own
# module puts on it. A reader whose gate changes must change here too.
#
# Ordering, never a requirement: a policy unit skips once the bootstrap token
# is gone, and a skipped unit counts as done. `wants` as well as `after`, so a
# reader started on its own pulls its policy unit into the same transaction.
{
  lib,
  config,
  ...
}:
let
  hyperhiveCfg = config.services.hyperhive;
  deployCfg = hyperhiveCfg.deploy;
  baoDeploy = deployCfg.bao;

  havePair = cert: key: cert != null && key != null;

  # Reader unit → the gate its own module defines it under.
  readersHere = {
    # ./glue-matrix-bao-token.nix
    swarm-bao-matrix-token =
      hyperhiveCfg.enable
      && havePair baoDeploy.matrixTokenClientCertFile baoDeploy.matrixTokenClientKeyFile
      && deployCfg.matrix.enable;
    # ./glue-queue-agent-credential.nix
    swarm-bao-queue-agent =
      hyperhiveCfg.enable
      && havePair baoDeploy.queueAgentClientCertFile baoDeploy.queueAgentClientKeyFile;
    # ./swarm-grafana.nix
    swarm-bao-grafana-oidc = hyperhiveCfg.enable && deployCfg.grafana.enable;
    # ./swarm-otel.nix
    swarm-bao-otel-oidc =
      deployCfg.swarm-otel.enable
      && havePair baoDeploy.otelOidcClientCertFile baoDeploy.otelOidcClientKeyFile;
    # ./swarm-bao.nix: its block is gated on the store, which `orderAfterPolicy`
    # already checks.
    swarm-bao-forwarder-oidc = hyperhiveCfg.enable;
    # ./swarm-nats.nix: the queue's TLS leaf, not a secret, but the same wait.
    swarm-bao-nats-tls = deployCfg.nats.enable;
  };

  orderAfterPolicy =
    reader: here:
    lib.mkIf (baoDeploy.enable && here) {
      systemd.services.${reader} = {
        after = [ "${reader}-policy.service" ];
        wants = [ "${reader}-policy.service" ];
      };
    };
in
{
  config = lib.mkMerge (lib.mapAttrsToList orderAfterPolicy readersHere);
}