{ pkgs, lib, config, ... }:
{
  # Shared scaffolding for any hyperhive harness container — both
  # sub-agents (`agent-base.nix`) and the manager (`manager.nix`) extend
  # this. The systemd service that actually runs the harness binary
  # differs per role and lives in the child module.

  options.hyperhive.allowedRecipients = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ ];
    example = [ "alice" "manager" ];
    description = ''
      Names this agent is allowed to `send` to via
      `mcp__hyperhive__send`. Empty list (the default) means
      unrestricted — the agent can message any peer, the
      operator, or the manager. Non-empty list constrains the
      surface: only the listed names + the manager (always
      allowed) get through; anything else returns an error
      string to claude without touching the broker. The
      operator (`operator`) needs to be in the list if the
      agent should be able to surface output on the
      dashboard.

      Useful for sandboxing untrusted sub-agents — set
      `[ "manager" ]` to scope them to manager-only chatter.
      The manager itself is always exempt; this option only
      affects sub-agent `send`.
    '';
  };

  options.hyperhive.extraMcpServers = lib.mkOption {
    type = lib.types.attrsOf (lib.types.submodule {
      options = {
        command = lib.mkOption {
          type = lib.types.str;
          description = "Absolute path to the MCP server binary. Use `\${pkgs.foo}/bin/foo` or `/run/current-system/sw/bin/foo`.";
        };
        args = lib.mkOption {
          type = lib.types.listOf lib.types.str;
          default = [ ];
          description = "Args passed to the MCP server binary.";
        };
        env = lib.mkOption {
          type = lib.types.attrsOf lib.types.str;
          default = { };
          description = "Environment variables for the MCP server child process.";
        };
        allowedTools = lib.mkOption {
          type = lib.types.listOf lib.types.str;
          default = [ "*" ];
          example = [ "send_message" "join_room" ];
          description = ''
            Tool names this MCP server is auto-approved to call via
            `--allowedTools`. Single entry `"*"` (the default) means
            "every tool from this server" — convenient but trusting.
            Tighten to a specific list when you only want a subset.
            Names are bare (e.g. `send_message`); the harness prepends
            `mcp__<server-key>__` at build time.
          '';
        };
      };
    });
    default = { };
    example = lib.literalExpression ''
      {
        matrix = {
          command = "/run/current-system/sw/bin/mcp-matrix";
          args = [ "--config" "/state/matrix.toml" ];
          env.MATRIX_HOMESERVER = "https://matrix.example.org";
          allowedTools = [ "send_message" "join_room" ];
        };
      }
    '';
    description = ''
      Extra MCP servers claude sees alongside the hyperhive tool surface.
      Keys are the server names (claude addresses tools as
      `mcp__<key>__<tool>`). Rendered to `/etc/hyperhive/extra-mcp.json`
      at activation time; the harness reads that file at boot and merges
      it into `--mcp-config` + `--allowedTools`. Take effect on the
      agent's next harness restart (no operator approval needed beyond
      whatever brought the new agent.nix into deployed/*).
    '';
  };

  options.hyperhive.forge.url = lib.mkOption {
    type = lib.types.str;
    default = "http://localhost:3000";
    example = "http://forge.internal:3000";
    description = ''
      Base URL of the hyperhive-managed Forgejo. Used at container
      boot by a oneshot systemd unit that calls
      `tea login add --url <this> --token "$(cat /state/forge-token)"`
      so the agent's claude can shell out to `tea` without an extra
      auth dance. No-op when `/state/forge-token` is missing (i.e.
      hive-forge isn't running on the host).
    '';
  };

  options.hyperhive.claudePlugins = lib.mkOption {
    type = lib.types.listOf lib.types.str;
    default = [ ];
    example = [ "formatter@my-marketplace" "thinking-tools@anthropics" ];
    description = ''
      Claude Code plugins to install at harness boot. Each entry is
      passed verbatim to `claude plugin install <spec>` once per
      container start, before the turn loop opens. `claude plugin
      install` is expected to be idempotent, so reinstalling on every
      boot is cheap. Failures log a warning but do not abort boot — a
      missing plugin is preferable to a non-serving agent. Rendered to
      `/etc/hyperhive/claude-plugins.json`; the harness reads it via
      `plugins::install_configured`.
    '';
  };

  config = {
    environment.etc."hyperhive/extra-mcp.json".text =
      builtins.toJSON config.hyperhive.extraMcpServers;

    environment.etc."hyperhive/send-allow.json".text =
      builtins.toJSON config.hyperhive.allowedRecipients;

    environment.etc."hyperhive/claude-plugins.json".text =
      builtins.toJSON config.hyperhive.claudePlugins;

    boot.isNspawnContainer = true;

    # `claude-code` is unfree. Each per-agent container's nixosConfiguration
    # evaluates its own `nixpkgs` instance, so the operator's host-level
    # `nixpkgs.config.allowUnfreePredicate` does not propagate into here —
    # we have to allow it inside the container's config as well.
    nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (pkgs.lib.getName pkg) [ "claude-code" ];

    environment.systemPackages = with pkgs; [
      hyperhive
      claude-code
      bashInteractive
      coreutils-full
      # procps for pkill — used by the web UI's /api/cancel to SIGINT the
      # in-flight claude turn.
      procps
      # tea: gitea/forgejo CLI client. Configured at boot by the
      # tea-login oneshot below if /state/forge-token is present, so
      # claude can `tea repos create`, `tea pulls create`, etc.
      tea
    ];

    # One-shot: configure tea with the agent's forge token if
    # hive-c0re seeded one and tea hasn't been configured yet.
    # Runs before the harness service so the first turn can already
    # `tea repos create`. Idempotent — exits 0 if config already
    # exists, exits 0 if no token file (hive-forge not enabled).
    systemd.services.tea-login = {
      description = "configure tea CLI from /state/forge-token";
      wantedBy = [ "multi-user.target" ];
      after = [ "local-fs.target" ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
      };
      path = [ pkgs.tea pkgs.coreutils ];
      script = ''
        set -eu
        CONFIG=/root/.config/tea/config.yml
        # Manager keeps the legacy /state bind; sub-agents have
        # /agents/<name>/state. Glob covers both — there's exactly one
        # hit either way (manager: /state, sub-agent: its own
        # /agents/* mount), since each container only sees its own
        # state dir.
        TOKEN_FILE=""
        for f in /state/forge-token /agents/*/state/forge-token; do
          [ -f "$f" ] && TOKEN_FILE="$f" && break
        done
        if [ -z "$TOKEN_FILE" ]; then
          echo "tea-login: no forge-token (hive-forge not seeded); skipping"
          exit 0
        fi
        if [ -f "$CONFIG" ]; then
          echo "tea-login: $CONFIG already present; skipping"
          exit 0
        fi
        mkdir -p "$(dirname "$CONFIG")"
        tea login add \
          --name forge \
          --url ${lib.escapeShellArg config.hyperhive.forge.url} \
          --token "$(cat "$TOKEN_FILE")"
        echo "tea-login: configured for ${config.hyperhive.forge.url} from $TOKEN_FILE"
      '';
    };

    # Git is needed by claude's Bash tool (for the agent <-> manager config
    # request flow) and by hive-c0re's own setup_applied / setup_proposed.
    # The per-agent `applied/<name>/flake.nix` overrides `user.name` and
    # `user.email` with the agent's identity — values here are `mkDefault`
    # so the per-agent override wins without needing `mkForce`.
    programs.git = {
      enable = true;
      config = {
        user = {
          name = lib.mkDefault "hyperhive";
          email = lib.mkDefault "hyperhive@local";
        };
        init.defaultBranch = lib.mkDefault "main";
      };
    };

    # claude's Bash tool refuses to run without a POSIX shell + $SHELL set.
    environment.variables.SHELL = "${pkgs.bashInteractive}/bin/bash";

    system.stateVersion = "25.11";
  };
}