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

{
  imports =
    [ ./nixpkgs.nix
      ./sif/hw.nix
      ./sif/boot.nix
      ./users.nix
      ./custom/zsh.nix
      ./custom/tinc/def.nix
      ./custom/tinc/yggdrasil.nix
      ./custom/uucp.nix
      ./custom/borgbackup.nix
      ./custom/uucp-mediaclient.nix
      ./custom/uucp-notifyclient.nix
      ./custom/notify-users.nix
      ./utils/nix/module.nix
    ];

  networking = {
    hostName = "sif";
    domain = "midgard.yggdrasil";

    hosts = {
      "127.0.0.1" = [ "sif.midgard.yggdrasil" "sif" ];
      "::1" = [ "sif.midgard.yggdrasil" "sif" ];
    };
    
    firewall = {
      enable = true;
      allowedTCPPorts = [ 22 # ssh
                          8000 # quickserve
                        ];
    };

    networkmanager = {
      enable = true;
      dhcp = "internal";
      dns = "dnsmasq";
      extraConfig = ''
        [connectivity]
        uri=https://online.yggdrasil.li
      '';
    };

    dhcpcd.enable = false;
  };

  environment.etc."NetworkManager/dnsmasq.d/libvirtd_dnsmasq.conf" = {
    text = ''
      server=/sif.libvirt/192.168.122.1
    '';
  };

  powerManagement.enable = true;

  i18n.defaultLocale = "en_US.UTF-8";
  console.keyMap = "dvp";

  time.timeZone = "Europe/Berlin";

  environment.systemPackages = with pkgs; [
    git rebuild-system
    nvtop
    brightnessctl
    pcsctools
    quickserve
  ];

  nixpkgs.config = {
    allowUnfree = true;
    packageOverrides = pkgs: rec {
      libfprint = pkgs.stdenv.mkDerivation rec {
        pname = "libfprint";
        version = "1.90.1";

        src = pkgs.fetchurl {
          url = "https://gitlab.freedesktop.org/libfprint/libfprint/uploads/662cd834e76c02c4d74ad01c50412759/libfprint-1.90.1.tar.xz";
          sha256 = "1pv6sd852i5i0sn1ki109jhk9indl21cb4aw7v6xhcnvjmgds0xx";
        };

        buildInputs = with pkgs; [ libusb pixman glib nss nspr gdk_pixbuf openssl gusb gobject-introspection gtk-doc cairo ];
        nativeBuildInputs = with pkgs; [ pkgconfig meson ninja ];

        mesonFlags = [ "-Dudev_rules_dir=$(out)/lib/udev/rules.d" "-Ddoc=false" ];
      };
      fprintd = pkgs.stdenv.mkDerivation rec {
        pname = "fprintd";
        version = "1.90.1";

        src = pkgs.fetchurl {
          url = "https://gitlab.freedesktop.org/libfprint/fprintd/uploads/a47c31c844e23e070665a8a85dae0144/fprintd-1.90.1.tar.xz";
          sha256 = "03d3r0hz9m3i71wxs5h048kam6k4bdlcg6xvy50kcah5zcfhp55l";
        };

        buildInputs = (with pkgs; [ glib polkit dbus dbus-glib systemd pam perl libxslt libxml2 python3]) ++ (with pkgs.python3Packages; [pycairo dbus-python python-dbusmock pygobject3 ]) ++ [ libfprint pam_wrapper ];
        nativeBuildInputs = with pkgs; [ pkgconfig meson ninja ];

        installPhase = ''
          install -vm 0755 -d $out/etc/dbus-1/interfaces $out/libexec $out/share/polkit-1/actions $out/share/man/man1 $out/share/man/man8 $out/bin $out/lib/security $out/etc/dbus-1/system.d $out/share/dbus-1/system-services $out/lib/systemd/system $out/etc $out/share/locale

          install -vt $out/etc/dbus-1/interfaces src/net.reactivated.Fprint.{Manager,Device}.xml
          install -vt $out/libexec src/fprintd
          install -vt $out/share/polkit-1/actions data/net.reactivated.fprint.device.policy
          install -vt $out/share/man/man1 data/fprintd.1 
          install -vt $out/share/man/man8 data/pam_fprintd.8
          install -vt $out/bin utils/fprintd-{delete,enroll,list,verify}
          install -vt $out/lib/security pam/pam_fprintd.so

          install -vt $out/etc/dbus-1/system.d /build/fprintd-${version}/data/net.reactivated.Fprint.conf
          install -vt $out/share/dbus-1/system-services /build/fprintd-${version}/build/data/net.reactivated.Fprint.service
          install -vt $out/lib/systemd/system /build/fprintd-${version}/build/data/fprintd.service
          install -vt $out/etc /build/fprintd-${version}/data/fprintd.conf

          for lang in /build/fprintd-${version}/build/po/*.gmo; do
            install -vD $lang $out/share/locale/$(basename $lang .gmo)/LC_MESSAGES/fprintd.mo
          done
        '';
      };
      pam_wrapper = pkgs.stdenv.mkDerivation rec {
        pname = "pam_wrapper";
        version = "1.0.7";

        src = pkgs.fetchurl {
          url = "mirror://samba/cwrap/${pname}-${version}.tar.gz";
          sha256 = "06djr20kk5sqgydkmfwllbm5ndv4jaqmkj1kab7ppc6fnqp30dq5";
        };

        nativeBuildInputs = with pkgs; [ pkgconfig ];
        buildInputs = with pkgs; [ cmake pam python3 ];
      };
    };
  };

  nixpkgs.overlays = [
    (self: super: {
      linuxPackages_latest = super.linuxPackages_latest.extend (self: super: {
        nvidiaPackages = super.nvidiaPackages // {
          stable = super.nvidiaPackages.stable.overrideAttrs (attrs: {
            patches = [
              (pkgs.fetchpatch {
                name = "nvidia-kernel-5.7.patch";
                url = "https://gitlab.com/snippets/1965550/raw";
                sha256 = "03iwxhkajk65phc0h5j7v4gr4fjj6mhxdn04pa57am5qax8i2g9w";
              })
            ];

            passthru = {
              inherit (super.nvidiaPackages.stable) settings persistenced persistencedVersion settingsVersion;
            };
          });
        };
      });
    })
  ];

  services = {
    pcscd.enable = true;
    
    avahi.enable = true;
    
    fwupd.enable = true;
    fprintd.enable = true;
    
    blueman.enable = true;
    
    colord.enable = true;
    
    vnstat.enable = true;

    printing = {
      enable = true;
      drivers = with pkgs; [ samsung-unified-linux-driver hplip ];
    };

    logind = {
      lidSwitch = "suspend";
      lidSwitchDocked = "lock";
      lidSwitchExternalPower = "lock";
    };

    openssh = {
      enable = true;
      knownHosts = import ./knownHosts.nix;
    };

    atd = {
      enable = true;
      allowEveryone = true;
    };

    xserver = {
      enable = true;
      
      layout = "us";
      xkbVariant = "dvp";
      xkbOptions = "compose:caps";
      
      displayManager.lightdm = {
        enable = true;
        greeters.gtk = {
          clock-format = "%H:%M %a %b %_d";
          indicators = ["~host" "~spacer" "~clock" "~session" "~power"];
          theme = {
            package = pkgs.equilux-theme;
            name = "Equilux-compact";
          };
          iconTheme = {
            package = pkgs.paper-icon-theme;
            name = "Paper";
          };
          extraConfig = ''
            background = #000000
            user-background = false
            active-monitor = #cursor
            hide-user-image = true

            [monitor: DP-2]
              laptop = true
          '';
        };
      };

      displayManager.setupCommands = ''
        ${pkgs.xorg.xinput}/bin/xinput disable 'SynPS/2 Synaptics TouchPad'
      '';

      desktopManager.xterm.enable = true;
      windowManager.twm.enable = true;
      displayManager.defaultSession = "xterm+twm";

      wacom.enable = true;
      libinput.enable = true;

      dpi = 282;

      videoDrivers = [ "nvidia" ];

      screenSection = ''
        Option "metamodes" "nvidia-auto-select +0+0 { ForceCompositionPipeline = On }"
      '';

      deviceSection = ''
        Option "AccelMethod" "SNA"
        Option "TearFree" "True"
      '';

      exportConfiguration = true;
    };

    yggdrasilTinc = {
      enable = true;
      connect = true;
      name = "sif";
      interfaceConfig = {
        macAddress = "5c:93:21:c3:61:39";
      };
    };

    uucp = {
      enable = true;
      nodeName = "sif";
      remoteNodes = {
        "odin" = {
          publicKeys = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIN87boeNNs2PhAcVXaO+nGFUo5MCpl0TFqwCNmxnHYSe root@odin"];
          hostnames = ["odin.asgard.yggdrasil"];
        };
        "ymir" = {
          publicKeys = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIG6KNtsCOl5fsZ4rV7udTulGMphJweLBoKapzerWNoLY root@ymir"];
          hostnames = ["ymir.yggdrasil.li" "ymir.niflheim.yggdrasil"];
        };
      };
      
      defaultCommands = lib.mkForce [];

      media-client = {
        remoteNodes = [ "odin" ];
        notify.users = [ "gkleen" ];
      };

      notify-client = {
        remoteNodes = {
          odin = {};
        };
      };
    };

    notify-users = [ "gkleen" ];
    
    postfix = {
      enable = true;
      enableSmtp = true;
      enableSubmission = false;
      setSendmail = true;
      networksStyle = "host";
      hostname = "sif.midgard.yggdrasil";
      destination = [];
      relayHost = "uucp:ymir";
      recipientDelimiter = "+";
      masterConfig = {
        uucp = {
          type = "unix";
          private = true;
          privileged = true;
          chroot = false;
          command = "pipe";
          args = [ "flags=Fqhu" "user=uucp" ''argv=${config.security.wrapperDir}/uux -z -a $sender - $nexthop!rmail ($recipient)'' ];
        };
        sshsendmail = {
          type = "unix";
          private = true;
          privileged = true;
          chroot = false;
          command = "pipe";
          args = [ "flags=Fq" "user=postfix_ssh" ''argv=${pkgs.openssh}/bin/ssh -F /var/db/postfix_ssh/ssh.config $nexthop sendmail -f $sender -G $recipient'' ];
        };
      };
      transport = ''
        odin.asgard.yggdrasil uucp:odin
      '';
      config = {
        always_bcc = "gkleen+sent@odin.asgard.yggdrasil";
      
        default_transport = "uucp:ymir";

        inet_interfaces = "loopback-only";
      
        authorized_submit_users = ["!uucp" "static:anyone"];
        message_size_limit = "0";

        sender_dependent_default_transport_maps = ''regexp:${pkgs.writeText "sender_relay" ''
          /@math(ematik)?\.(lmu|uni-muenchen)\.de$/ sshsendmail:math60.mathinst.loc
          /@(cip|stud)\.ifi\.(lmu|uni-muenchen)\.de$/ smtp:smtp.ifi.lmu.de
          /@ifi\.(lmu|uni-muenchen)\.de$/ smtp:smtpin1.ifi.lmu.de:587
          /@(campus\.)?lmu\.de$/ smtp:postout.lrz.de
        ''}'';
        sender_bcc_maps = ''texthash:${pkgs.writeText "sender_bcc" ''
          uni2work@ifi.lmu.de uni2work@ifi.lmu.de
          @ifi.lmu.de gregor.kleen@ifi.lmu.de
        ''}'';

        smtp_sasl_auth_enable = true;
        smtp_sender_dependent_authentication = true;
        smtp_sasl_tls_security_options = "noanonymous";
        smtp_sasl_mechanism_filter = ["plain"];
        smtp_sasl_password_maps = "texthash:/var/db/postfix/sasl_passwd";
        smtp_cname_overrides_servername = false;
        smtp_always_send_ehlo = true;

        smtp_tls_loglevel = "1";
        smtp_dns_support_level = "dnssec";
      };
      useDane = true;
    };

    upower = {
      enable = true;
    };

    locate = {
      enable = true;
      interval = "hourly";
      locate = pkgs.mlocate;
      localuser = null;
      prunePaths = ["/tmp" "/var/tmp" "/var/cache" "/var/lock" "/var/run" "/var/spool"];
    };
  };

  users = {
    mutableUsers = false;
  
    extraUsers.root = { inherit (import ./users/gkleen.nix) shell hashedPassword; };

    extraUsers.gkleen.extraGroups = [ "media" "networkmanager" ];

    extraUsers.postfix_ssh = {
      isSystemUser = true;
      home = "/var/db/postfix_ssh";
    };

    extraGroups = {
      network = {};
    };
  };

  security = {
    sudo.extraConfig = ''
      Cmnd_Alias  SYSCTRL = /run/current-system/sw/sbin/shutdown, /run/current-system/sw/sbin/reboot, /run/current-system/sw/sbin/halt, /run/current-system/sw/bin/systemctl
      %wheel ALL=(ALL) NOPASSWD: SYSCTRL
    '';

    wrappers = { "mount".source = "${pkgs.utillinux.bin}/bin/mount";
                 "umount".source = "${pkgs.utillinux.bin}/bin/umount";
                 "newgrp".source = "${pkgs.shadow}/bin/newgrp";
                 "sg".source = "${pkgs.shadow}/bin/sg";
               };

    polkit = {
      enable = true;
      extraConfig = ''
        polkit.addRule(function(action, subject) {
          if (    action.id == "org.freedesktop.systemd1.manage-units"
               && subject.isInGroup("wheel")
             ) {
            return polkit.Result.YES;
          }
        });

        polkit.addRule(function(action, subject) {
          if ((action.id == "org.blueman.rfkill.setstate" ||
               action.id == "org.blueman.network.setup" ||
               action.id == "org.freedesktop.NetworkManager.settings.modify.system"
              ) && subject.local
              && subject.active && subject.isInGroup("network")
             ) {
            return polkit.Result.YES;
          }
        });
      '';
    };
  };

  hardware = {
    pulseaudio = {
      enable = true;
      package = with pkgs; pulseaudioFull;
      support32Bit = true;
    };

    bluetooth = {
      enable = true;   
      config = {
        General = {
          Enable = "Source,Sink,Media,Socket";
        };
      };
    };

    trackpoint = {
      enable = true;
      emulateWheel = true;
      sensitivity = 255;
      speed = 255;
    };

    nvidia = {
      modesetting.enable = true;
      prime = {
        nvidiaBusId = "PCI:1:0:0";
        intelBusId = "PCI:0:2:0";
        sync.enable = true;
      };
    };

    opengl = {
      enable = true;
      driSupport32Bit = true;
      setLdLibraryPath = true;
    };

    firmware = [ pkgs.firmwareLinuxNonfree ];
  };

  sound.enable = true;

  nix = {
    useSandbox = true;
    autoOptimiseStore = true;
    daemonNiceLevel = 10;
    daemonIONiceLevel = 3;
  };

  environment.etc."X11/xorg.conf.d/50-wacom.conf".source = lib.mkForce ./sif/wacom.conf;

  systemd.services."kill-user@" = {
    serviceConfig = {
      Type = "oneshot";
      ExecStart = "${pkgs.systemd}/bin/loginctl kill-user %I";
    };
  };
  systemd.targets."sleep" = {
    after = [ "kill-user@uucp.service" ];
    wants = [ "kill-user@uucp.service" ];
  };


  systemd.user.services."ssh-agent".enable = lib.mkForce false;

  systemd.services."ac-plugged" = {
    description = "Inhibit handling of lid-switch and sleep";

    path = with pkgs;
             [ systemd coreutils ];

    script = ''
      exec systemd-inhibit --what=handle-lid-switch --why="AC is connected" --mode=block sleep infinity
    '';
  
    serviceConfig = {
      Type = "simple";
    };
  };

  services.udev.extraRules = with pkgs; ''
    SUBSYSTEM=="power_supply", ENV{POWER_SUPPLY_ONLINE}=="0", RUN+="${systemd}/bin/systemctl --no-block stop ac-plugged.service"
    SUBSYSTEM=="power_supply", ENV{POWER_SUPPLY_ONLINE}=="1", RUN+="${systemd}/bin/systemctl --no-block start ac-plugged.service"
  '';

  services.borgbackup = {
    snapshots = "btrfs";
    prefix = "yggdrasil.midgard.sif.";
    targets = {
      "munin" = {
        repo = "borg.munin:borg";
        paths = [ "/home/gkleen" ];
        prune = {
          "home" =
            [ "--keep-within" "24H"
              "--keep-daily" "31"
              "--keep-monthly" "12"
              "--keep-yearly" "-1"
            ];
        };
      };
    };
  };

  services.btrfs.autoScrub = {
    enable = true;
    fileSystems = [ "/" "/home" ];
    interval = "weekly";
  };

  systemd.services."nix-daemon".serviceConfig = {
    MemoryAccounting = true;
    MemoryHigh = "50%";
    MemoryMax = "75%";
  };

  systemd.services."nixos-upgrade" = {
    path = with pkgs; [ git ];
    preStart = ''
      git -C /etc/nixos fetch --recurse-submodules
      git -C /etc/nixos reset --hard origin/master
    '';
  };

  services.compton = {
    enable = true;
    backend = "glx";
    vSync = true;
    settings = {
      glx-swap-method = 3;
      xrender-sync-fence = true;
    };
  };

  services.journald.extraConfig = ''
    SystemMaxUse=100M
  '';

  services.dbus.packages = with pkgs;
    [ dbus gnome3.dconf
    ];

  programs = {
    light.enable = true;
    wireshark.enable = true;
  };

  virtualisation.libvirtd = {
    enable = true;
  };

  zramSwap.enable = true;

  nix = {
    package = with pkgs; nixFlakes;
    extraOptions = ''
      experimental-features = nix-command flakes
    '';
  };

  system.stateVersion = "20.03"; # Did you read the comment?
}