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

  # Matrix's enable signal, which is the account set itself — there is no
  # `matrix.enable` option left to read. Three arms, because the property has
  # three distinct shapes and only one of them is the common case:
  #
  # - a homeserver URL, which is what the module turns into a `main` account;
  # - neither URL nor operator account, the state that replaced
  #   `matrix.enable = false`. ⚠️ **This is the arm that matters.** `main` is
  #   declared by the module itself, so "any account declared" would be
  #   trivially true — and matrix would render for every agent in every hive —
  #   the moment that declaration stops being gated on the URL. Nothing else in
  #   this suite would notice;
  # - an operator account carrying its own homeserver and no hive one, which is
  #   matrix on with no `main` at all.
  agentMatrix = agent { matrix.url = "https://chat.t.local"; };

  agentNoMatrix = agent { };

  agentMatrixExternalOnly = agent {
    matrixAccounts.ccc = {
      tokenFile = "/agents/a1/state/matrix-token-ccc";
      sessionDir = "/agents/a1/state/matrix-sdk-state-ccc";
      homeserver = "https://matrix.example.invalid";
    };
  };
  # The daemon that reads its tokens from the store, `main` included. Paired
  # with `agentMatrix` above — same daemon, no store — so each case below can
  # tell "carries the store's coordinates" from "every matrix daemon does".
  agentMatrixBao = agentWith {
    services.hyperhive.agent.bao.addr = "https://bao.t.local:8200";
    services.hyperhive.agent.matrix.url = "https://chat.t.local";
  };

  daemon = machine: machine.systemd.services.hive-matrix-daemon;
  cases = [
    {
      # A homeserver URL is the whole input: from it the module derives the
      # hive-internal `main` account, and from a non-empty account set the three
      # things that used to hang off `matrix.enable`.
      name = "an agent with a homeserver gets a main account and the matrix units";
      ok =
        let
          a = agentMatrix.services.hyperhive.agent.matrixAccounts;
        in
        lib.attrNames a == [ "main" ]
        && a.main.tokenFile == "/agents/a1/state/matrix-token"
        && a.main.homeserver == "https://chat.t.local"
        && agentMatrix.systemd.services ? hive-matrix-daemon
        && agentMatrix.systemd.paths ? hive-matrix-daemon
        && agentMatrix.services.hyperhive.agent.extraMcpServers ? matrix;
    }
    {
      # The absence arm, and the reason the enable signal is not vacuous. An
      # agent the hive gave no homeserver, whose operator declared nothing, must
      # come out with an EMPTY account set — not a `main` that can never log in
      # — and therefore with none of the three. Assert the emptiness itself and
      # not just the units: it is the account set that is load-bearing now, and
      # a `main` sneaking back in is the regression this case exists to name.
      name = "an agent with no homeserver and no declared account gets no matrix at all";
      ok =
        agentNoMatrix.services.hyperhive.agent.matrixAccounts == { }
        && !(agentNoMatrix.systemd.services ? hive-matrix-daemon)
        && !(agentNoMatrix.systemd.paths ? hive-matrix-daemon)
        && !(agentNoMatrix.services.hyperhive.agent.extraMcpServers ? matrix);
    }
    {
      # Matrix without a hive homeserver: one operator account, its own
      # homeserver, no `main`. Under the deleted `matrix.enable` this config was
      # an assertion failure ("extras require enable") even though every account
      # in it was complete; the account set being the signal is what makes it
      # expressible, and the serialized env var is where that has to show up.
      name = "an external-only account enables matrix with no main entry";
      ok =
        let
          accts = agentMatrixExternalOnly.services.hyperhive.agent.matrixAccounts;
          env = agentMatrixExternalOnly.systemd.services.hive-matrix-daemon.environment;
        in
        lib.attrNames accts == [ "ccc" ]
        && !(accts ? main)
        &&
          builtins.fromJSON env.HIVE_MATRIX_ACCOUNTS == [
            {
              name = "ccc";
              token_file = "/agents/a1/state/matrix-token-ccc";
              state_dir = "/agents/a1/state/matrix-sdk-state-ccc";
              homeserver = "https://matrix.example.invalid";
            }
          ]
        # No hive homeserver, so nothing may claim one.
        && !(env ? HIVE_MATRIX_URL);
    }
    {
      # The daemon reads this agent's tokens from the store ITSELF, as itself,
      # from inside this container — `main` too, since the swarm mints it and
      # no hive does. So it needs the same identity ./agent-forge-bao.nix's
      # fetch carries, in its own credentials directory.
      name = "the matrix daemon carries this agent's own store identity";
      ok =
        let
          u = daemon agentMatrixBao;
        in
        u.serviceConfig.LoadCredential == [
          "hive-agent-bao-cert"
          "hive-agent-bao-key"
          "hive-agent-bao-server-ca"
        ]
        && u.environment.BAO_ADDR == "https://bao.t.local:8200"
        && u.environment.BAO_CLIENT_CERT == "%d/hive-agent-bao-cert"
        && u.environment.BAO_CLIENT_KEY == "%d/hive-agent-bao-key";
    }
    {
      # The agent's name, and nothing derived from it: the daemon builds its
      # store path and its cert-auth role from this one string.
      name = "the matrix daemon is told which agent it is and not where its credentials live";
      ok =
        let
          e = (daemon agentMatrixBao).environment;
        in
        e.HIVE_AGENT_NAME == agentMatrixBao.services.hyperhive.agent.user.name
        && !(lib.any (lib.hasInfix "swarm/agents") (lib.attrValues e));
    }
    {
      # 🩸 A secret is a path: every `BAO_*` entry is the store's address or a
      # file under this unit's own credentials directory, never bytes in an
      # environment `/proc/<pid>/environ` publishes.
      name = "the matrix daemon is handed store paths and never store values";
      ok =
        let
          store = lib.filterAttrs (n: _: lib.hasPrefix "BAO_" n) (daemon agentMatrixBao).environment;
        in
        store != { }
        && lib.all (n: n == "BAO_ADDR" || lib.hasPrefix "%d/" store.${n}) (lib.attrNames store);
    }
    {
      # A token the swarm mints or replaces in the store changes no file, so
      # the path watcher never sees it. The timer is what re-starts a daemon
      # that exited on a missing or replaced token.
      name = "a store-backed matrix daemon is re-started while it is down";
      ok =
        agentMatrixBao.systemd.timers.hive-matrix-daemon.timerConfig.OnUnitInactiveSec or null == "5min";
    }
    {
      # The absence arm for the four above: with no store, no identity, no
      # timer, and the file is the whole mechanism.
      name = "a matrix daemon on an agent with no store declares no identity and no timer";
      ok =
        let
          u = daemon agentMatrix;
        in
        !(u.serviceConfig ? LoadCredential)
        && !(u.environment ? BAO_ADDR)
        && !(u.environment ? HIVE_AGENT_NAME)
        && !(agentMatrix.systemd.timers ? hive-matrix-daemon);
    }
  ];
in
runGroup "agent-matrix" cases