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

# rollback to a previously working channel version, useful
# when "doas nixos-rebuild switch --upgrade" breaks:
#
# $ doas nix-channel --rollback

{
  imports = [ /etc/nixos/hardware-configuration.nix ];

  # Use the systemd-boot EFI boot loader.
  boot = {
    loader = {
      efi.canTouchEfiVariables = true;
      grub = {
        enable = true;
        version = 2;
        efiSupport = true;
        device = "nodev";
      };
    };
    initrd.luks.devices = {
      crypted = {
        device = "/dev/nvme0n1p2";
        preLVM = true;
      };
    };
  };

  hardware = {
    bluetooth.enable = true;
    pulseaudio = {
      enable = true;
      extraConfig = ''
        load-module module-echo-cancel
      '';
    };
  };

  networking = {
    hostName = "usurpador";
    networkmanager.enable = true;
  };

  console.keyMap = "br-abnt2";
  i18n.defaultLocale = "fr_FR.UTF-8";
  time.timeZone = "America/Sao_Paulo";

  programs.less.enable = lib.mkForce false;

  environment = {
    systemPackages = with pkgs; [
      xmobar
      i3lock

      slack
      zoom-us
      kubernetes
      tektoncd-cli
      aws-iam-authenticator
      flutter
      hover
      dart
    ];
  };

  nixpkgs = {
    config = {
      android_sdk.accept_license = true;
      allowUnfree = true;
    };
  };

  services = {
    upower.enable = true;
    fprintd.enable = true;
    blueman.enable = true;
    pcscd.enable = true;

    postfix = {
      enable = true;
      extraConfig = ''
        mynetworks = 127.0.0.0/8

        header_checks = regexp:{ { /^Received:.*/ IGNORE }, { /^X-Originating-IP:.*/ IGNORE } }

        sender_dependent_relayhost_maps = hash:/var/lib/private/postfix/relayhosts-maps
        smtp_sasl_password_maps = hash:/var/lib/private/postfix/sasl-password
        smtp_sasl_auth_enable = yes
        smtp_sasl_security_options = noanonymous
        smtp_tls_security_level = encrypt
        smtp_tls_note_starttls_offer = yes
        smtp_use_tls = yes
        smtp_sender_dependent_authentication = yes
        smtp_sasl_mechanism_filter = login, plain
      '';
      config = { smtp_tls_security_level = "encrypt"; };
      extraAliases = ''
        root: andreh
        andreh: eu@euandre.org
      '';
    };

    openssh = {
      enable = true;
      settings = {
        PermitRootLogin = "no";
        PasswordAuthentication = false;
      };
    };

    xserver = {
      enable = true;
      layout = "br";
      xkbOptions = "caps:swapescape";

      # Touchpad support
      libinput.enable = true;

      windowManager.xmonad = {
        enable = true;
        enableContribAndExtras = true;
      };
    };
  };

  users = {
    extraUsers = let
      andrehUser = {
        andreh = {
          isNormalUser = true;
          uid = 1000;
          description = "EuAndreh";
          extraGroups = [ "wheel" "networkmanager" "docker" ];
        };
      };
      # From the Guix manual:
      # https://www.gnu.org/software/guix/manual/en/html_node/Build-Environment-Setup.html#Build-Environment-Setup
      buildUser = (i: {
        "guixbuilder${i}" = { # guixbuilder$i
          group = "guixbuild"; # -g guixbuild
          extraGroups = [ "guixbuild" ]; # -G guixbuild
          home = "/var/empty"; # -d /var/empty
          shell = pkgs.shadow; # -s `which nologin`
          description = "Guix build user ${i}"; # -c "Guix buid user $i"
          isSystemUser = true; # --system
        };
      });
      # merge all users
    in pkgs.lib.fold (str: acc: acc // buildUser str) andrehUser
    # for i in `seq -w 1 10`
    (map (pkgs.lib.fixedWidthNumber 2) (builtins.genList (n: n + 1) 10));

    extraGroups.guixbuild = { name = "guixbuild"; };
  };

  systemd = {
    services = {
      # Derived from Guix guix-daemon.service.in
      # https://git.savannah.gnu.org/cgit/guix.git/tree/etc/guix-daemon.service.in?id=00c86a888488b16ce30634d3a3a9d871ed6734a2
      guix-daemon = {
        enable = true;
        description = "Build daemon for GNU Guix";
        serviceConfig = {
          ExecStart =
            "/var/guix/profiles/per-user/root/current-guix/bin/guix-daemon --build-users-group=guixbuild --substitute-urls='https://substitutes.nonguix.org https://ci.guix.gnu.org https://bordeaux.guix.gnu.org'";
        };
        wantedBy = [ "multi-user.target" ];
      };
    };
  };

  system = {
    stateVersion = "20.03";
    autoUpgrade = {
      enable = true;
      dates = "0:10";
    };
  };

  virtualisation.docker.enable = true;
}