# This module defines options for use by all C3D2 machines.

{ options, config, lib, pkgs, ... }:

let
  cfg = config.c3d2;
  neighMod = with lib; types.submodule {
    options = {
      addrs = mkOption {
        type = with types; attrsOf str;
        default = { };
      };
      via = mkOption
        {
          type = with types; listOf str;
          default = [ ];
        };
    } // (with builtins; let value = mkOption { type = types.str; }; in
    listToAttrs (map (name: { inherit name value; }) [ "exchpub" "id" "noisepub" "signpub" ]));
  };
in
{
  options.c3d2 = with lib;
    with lib.types; {

      acmeEmail = mkOption {
        type = str;
        default = "mail@c3d2.de";
        description = ''
          Admin email address to use for Letsencrypt
        '';
      };

      allUsersCanSshRoot = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = ''
          Let all people in <literal>c3d2.users</literal>
          login as root for deployment via SSH.
        '';
      };

      isInHq = mkEnableOption "HQ presence (TODO: what is this? association to VLAN 5?)";

      enableMotd = mkOption {
        type = bool;
        default = cfg.isInHq;
        defaultText = literalExample "config.c3d2.isInHq";
      };

      mergeHostsFile = mkOption {
        type = bool;
        default = cfg.isInHq;
        description = ''
          Whether to add <literal>c3d2.hosts</literal> to /etc/hosts.
        '';
      };

      mergeNncpSettings = mkEnableOption ''
        Whether to merge <literal>c3d2.nncp.<…>.nncp</literal>
        into <literal>programs.nncp.settings</literal>.
      '';

      k-ot.enable = mkEnableOption ''
        Add k-ot user to this machine. Anyone with an SSH key listed in
        <literal>c3d2.users</literal> can log in as this user.
      '';

      hq = {
        interface = mkOption {
          type = nullOr str;
          default = null;
          example = "eth0";
          description = ''
            Configure the given interface name with an internal IP address.
          '';
        };

        enableBinaryCache = mkOption {
          type = bool;
          default = cfg.isInHq;
          defaultText = literalExample "config.c3d2.isInHq";
          description = "Whether to enable the local Nix binary cache";
        };

        enableMpdProxy = mkOption {
          type = bool;
          default = false;
          description = "Whether to proxy the local MPD database";
        };

      };

      hosts =
        mkOption {
          type = attrsOf (submodule {
            options = {
              ether = mkOption {
                type = with types; nullOr str;
                default = null;
              };
              ip4 = mkOption {
                type = with types; nullOr str;
                default = null;
              };
              ip6 = mkOption {
                type = with types; nullOr str;
                default = null;
              };
              publicKey = mkOption {
                type = with types; nullOr str;
                default = null;
              };
              wol = mkOption {
                type = types.bool;
                default = false;
              };
              serial = mkOption {
                type = with types; nullOr str;
                default = null;
                description = ''
                  Hardware serial number to help identification when netbooting.
                '';
              };
            };
          });
        };

      nncp = {
        neigh = mkOption {
          type = with types; attrsOf neighMod;
          default = { };
          description = ''
            Attrset of NNCP neighbours for relaying packets.
            User endpoints go in <literal>c3d2.users</literal>.
          '';
        };
      };

      users =
        mkOption {
          type = attrsOf
            (submodule {
              options = {
                sshKeys = mkOption {
                  type = with types;
                    listOf str;
                  default = [ ];
                };
              };
            });
        };

    };
  config =
    let
      adminKeys = (with builtins; lib.lists.flatten (
        map
          (getAttr "sshKeys")
          (attrValues cfg.users)
      ));
    in
    {
      networking.hosts = lib.mkIf cfg.mergeHostsFile
        ((
          lib.attrsets.mapAttrs' (n: v: { name = v.ip4; value = [ "${n}.c3d2" ]; })
            (lib.attrsets.filterAttrs (n: v: v.ip4 != null) cfg.hosts)
        ) // (
          lib.attrsets.mapAttrs' (n: v: { name = v.ip6; value = [ "${n}.c3d2" ]; })
            (lib.attrsets.filterAttrs (n: v: v.ip6 != null) cfg.hosts)
        ));

      programs = lib.optionalAttrs (options.programs ? nncp) {
        nncp.settings = lib.optionalAttrs cfg.mergeNncpSettings cfg.nncp;
      };

      users.motd = lib.mkIf cfg.enableMotd (builtins.readFile ./motd);

      users.users.k-ot = lib.mkIf cfg.k-ot.enable {
        packages = with pkgs; [ screen tmux ];
        createHome = true;
        isNormalUser = true;
        uid = 1000;
        extraGroups = [ "audio" "video" "wheel" ];
        password = "k-otk-ot";
        openssh.authorizedKeys.keys = adminKeys;
      };

      users.users.root.openssh.authorizedKeys.keys = lib.mkIf cfg.allUsersCanSshRoot adminKeys;
    };
}