# `checks.module-eval-agent-memory` — see ./lib.nix for the shared
# rationale (why this suite exists, naming convention, "evaluates
# not executes").
{
  pkgs,
  lib,
  self,
  nixosSystem,
  shared,
}:
let
  inherit
    (import ./lib.nix {
      inherit
        pkgs
        lib
        self
        nixosSystem
        ;
    })
    runGroup
    agentHarness
    ;

  agentDefault = shared.agentBare;

  agentBashDaemon = machine: machine.systemd.services.hive-bash-daemon;
  agentSubagentDaemon = machine: machine.systemd.services.hive-subagent-daemon;
  cases = [
    {
      # The ceiling is sized at boot from the container's cap
      # (../agent-modules/memory-cap.nix). One in the unit would be the cap at
      # the last rebuild, and every agent would carry its own hive's number.
      name = "the subagent daemon's memory ceiling is not built into its unit";
      ok = !((agentSubagentDaemon agentDefault).serviceConfig ? MemoryHigh);
    }
    {
      # claude's heap ceiling reaches it only as inherited environment: the
      # environment generator fills the manager's, systemd hands that to every
      # unit, and both units spawn claude as a plain child. A unit that sets
      # or unsets the variable itself cuts that. Without the two generators the
      # cap reaches nothing, and without the check unit nothing says so.
      name = "claude's units take the heap ceiling from the memory cap read at boot";
      ok =
        let
          leavesIt =
            unit:
            !(unit.environment ? BUN_JSC_forceRAMSize)
            && !(lib.elem "BUN_JSC_forceRAMSize" (lib.toList (unit.serviceConfig.UnsetEnvironment or [ ])));
        in
        leavesIt (agentHarness agentDefault)
        && leavesIt (agentSubagentDaemon agentDefault)
        && agentDefault.environment.etc ? "systemd/system-environment-generators/50-hyperhive-memory-cap"
        && agentDefault.systemd.generators ? hyperhive-memory-cap
        && lib.elem "multi-user.target" agentDefault.systemd.services.hyperhive-memory-cap-check.wantedBy;
    }
    {
      # A HIGHER OOMScoreAdjust is a MORE likely victim. The subagent daemon
      # puts each run at +1000 itself and bash tasks stay at 0, so the harness
      # must sit below 0 for the agent's own session to go last. Neither
      # daemon unit carries a value: it would make the idle daemon a likelier
      # victim than a bash task, and a floor no run under it could go below.
      name = "the OOM killer takes the agent's own session last";
      ok =
        (agentHarness agentDefault).serviceConfig.OOMScoreAdjust < 0
        && !((agentSubagentDaemon agentDefault).serviceConfig ? OOMScoreAdjust)
        && !((agentBashDaemon agentDefault).serviceConfig ? OOMScoreAdjust);
    }
    {
      # Both daemons create a cgroup per run under their own; without the
      # delegation they cannot, and without the `daemon` leaf (the name
      # hive-agent-sock's `run_cgroup` looks for) they refuse to, so runs
      # would share the daemon's cgroup again.
      name = "the subagent and bash daemons are delegated their cgroup";
      ok =
        lib.all
          (
            unit:
            unit.serviceConfig.Delegate or null == "memory pids"
            && unit.serviceConfig.DelegateSubgroup or null == "daemon"
          )
          [
            (agentSubagentDaemon agentDefault)
            (agentBashDaemon agentDefault)
          ];
    }
    {
      # Preferring a subagent run as the victim is an improvement only if
      # losing one run isn't losing all of them. systemd's default `stop`
      # would take the daemon and every sibling session down with whichever
      # process the kernel chose.
      name = "one subagent losing the OOM draw does not stop the daemon";
      ok = (agentSubagentDaemon agentDefault).serviceConfig.OOMPolicy == "continue";
    }
    {
      # Every bash task runs under the daemon's unit; under `stop` one
      # OOM-killed task would end every running sibling task.
      name = "one bash task losing the OOM draw does not stop the daemon";
      ok = (agentBashDaemon agentDefault).serviceConfig.OOMPolicy or null == "continue";
    }
  ];
in
runGroup "agent-memory" cases