# Glue: tell the swarm controller where the swarm's collector is and which
# authelia runs on this host.
#
# ONE PAIRING PER FILE — controller ← the services whose coordinates it reads
# from the environment. Deleting this leaves a controller that exports no
# metrics, and a `swarmctl` that fails `user add` saying the authelia binary and
# users file are unset.
#
# ⚠️ Everything here is gated on the controller being here:
# `systemd.services.swarm-controller.environment` on a host without the
# controller would define a unit with no ExecStart.
#
# authelia → `swarmctl`'s wrapper, not the daemon's unit. Also gated on authelia
# running HERE: the controller can be enabled on a host that is not the swarm's
# SSO host, and there `swarmctl user add` must fail saying the value is unset —
# a guessed path would resolve cleanly and write a file nothing reads. The
# CONFIGURED authelia, not whatever is on PATH: the argon2 parameters baked into
# a hash have to match the verifier's.
#
# collector → the daemon's unit. `vcs_metrics`/`hive_jobq_metrics` read the
# standard `OTEL_EXPORTER_OTLP_ENDPOINT` and are silent no-ops without it. No
# gate beyond the controller: the controller always exports to the swarm's
# collector, which the swarm always has (./swarm-bao.nix,
# ./glue-swarm-otel-oidc-client.nix), and `deploy.swarm-otel.enable` only says it
# runs HERE. The endpoint is its swarm-service name through the gateway, never a
# loopback literal, with no trailing slash: the http exporter appends
# `/v1/metrics` and the gateway route strips `/${producerName}`. The port suffix
# is elided on 443, as in ./swarm-bao.nix.
# `SWARM_CONTROLLER_OTEL_AUDIENCE` is the audience ./glue-controller-oidc-client.nix
# registers and ./swarm-otel.nix's `oidc/${producerName}` authenticator checks.
{
  lib,
  config,
  ...
}:
let
  hyperhiveCfg = config.services.hyperhive;
  deployCfg = hyperhiveCfg.deploy;
  otelSwarmCfg = hyperhiveCfg.swarm.otel;
  queueClientId = hyperhiveCfg.swarm.controller.queueClientId;
  gatewayPortSuffix = lib.optionalString (
    hyperhiveCfg.gateway.httpsPort != 443
  ) ":${toString hyperhiveCfg.gateway.httpsPort}";
in
{
  config = lib.mkIf deployCfg.swarm-controller.enable (
    lib.mkMerge [
      (lib.mkIf deployCfg.authelia.enable {
        services.hyperhive.deploy.swarm-controller.swarmctlEnvironment = {
          SWARMCTL_AUTHELIA_BIN = "${deployCfg.authelia.package}/bin/authelia";
          SWARMCTL_AUTHELIA_USERS_FILE = deployCfg.authelia.hostUsersFile;
        };
      })
      {
        systemd.services.swarm-controller.environment = {
          OTEL_EXPORTER_OTLP_ENDPOINT = "https://${otelSwarmCfg.domain}${gatewayPortSuffix}/${otelSwarmCfg.producerName}";
          SWARM_CONTROLLER_OTEL_AUDIENCE = queueClientId;
        };
      }
    ]
  );
}