{ host }:

{ config, pkgs, ... }:
let
  m-labs = import (fetchTarball https://nixbld.m-labs.hk/channel/custom/artiq/full/artiq-full/nixexprs.tar.xz) { inherit pkgs; };
  pkgs-unstable = import (pkgs.fetchFromGitHub {
    owner = "nixos";
    repo = "nixpkgs";
    rev = "2ec0c698eaf3e7a4d13988538f08d65b3d006f40";
    sha256 = "137py5fhmjs3p1dgqmd7cxsxzzs67nrqqijxmflb0ck1fnfzrij7";
  }) {};
in
{
  deployment.targetHost = host;
  deployment.hasFastConnection = true;
  nix.nixPath = [ "nixpkgs=${pkgs.path}" ];
  programs.command-not-found.dbPath = "${pkgs.path}/programs.sqlite";

  imports =
    [
      (./. + "/${host}-hardware-configuration.nix")
    ];
  nixpkgs.config.packageOverrides = super: let self = super.pkgs; in {
    pam_p11 = super.pam_p11.overrideAttrs(oa: {
      patchPhase = oa.patchPhase or "" + ''
          substituteInPlace src/match_openssh.c --replace \
            '"%s/.ssh/authorized_keys", pw->pw_dir)' \
            '"/etc/ssh/authorized_keys.d/%s", pw->pw_name)'
        '';
    });
  };

  networking.hostName = host;
  networking.firewall.allowedTCPPorts = [ 1883 ];
  networking.firewall.allowedUDPPorts = [ 1883 ];

  time.timeZone = "Asia/Hong_Kong";

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  nixpkgs.config.allowUnfree = true;
  environment.systemPackages = with pkgs; [
    opensc yubikey-manager yubikey-manager-qt yubico-piv-tool
    wget vim gitAndTools.gitFull sshfs firefox chromium thunderbird hexchat
    usbutils pciutils uhubctl file lm_sensors audacious acpi
    gimp imagemagick
    (python3.withPackages(ps: with ps; [ numpy scipy matplotlib qtconsole regex ]))
    mosh psmisc libreoffice-fresh
    gtkwave telnet unzip zip gnupg
    gnome3.gnome-tweaks
    jq sublime3 rink qemu_kvm
    tmux xc3sprog m-labs.openocd screen gdb minicom picocom tigervnc
    emacs bat ripgrep
    xpra
    rust-analyzer
    (vscode-with-extensions.override {
      vscodeExtensions = [
        vscode-extensions.matklad.rust-analyzer
      ];
    })
    pkgs-unstable.joplin-desktop
    virt-manager spice-gtk
    (callPackage ./any-nix-shell.nix {})
  ];
  programs.wireshark.enable = true;
  programs.wireshark.package = pkgs.wireshark;
  virtualisation.libvirtd.enable = true;
  virtualisation.libvirtd.qemuOvmf = true;
  security.wrappers.spice-client-glib-usb-acl-helper.source = "${pkgs.spice-gtk}/bin/spice-client-glib-usb-acl-helper";

  services.openssh.enable = true;
  services.openssh.forwardX11 = true;
  services.openssh.passwordAuthentication = false;
  services.openssh.extraConfig =
    ''
    StreamLocalBindUnlink yes
    '';
  programs.mosh.enable = true;

  services.pcscd.enable = true;
  programs.ssh.extraConfig =
    ''
    PKCS11Provider "${pkgs.opensc}/lib/opensc-pkcs11.so"
    '';
  programs.ssh.startAgent = true;
  services.gnome.gnome-keyring.enable = pkgs.lib.mkForce false;
  programs.ssh.agentPKCS11Whitelist = "${pkgs.opensc}/lib/opensc-pkcs11.so";
  security.pam.p11.enable = true;

  # Enable CUPS to print documents.
  services.printing = {
    enable = true;
    extraConf =
      ''
      Browsing Off
      BrowseLocalProtocols none
      '';
    browsedConf =
      ''
      BrowseRemoteProtocols none
      BrowseProtocols none
      '';
  };
  services.avahi = {
    enable = true;
    nssmdns = true;
  };

  # Enable sound.
  sound.enable = true;
  hardware.pulseaudio = {
    enable = true;
    extraModules = [ pkgs.pulseaudio-modules-bt ];
    package = pkgs.pulseaudioFull;
  };

  i18n.inputMethod = {
    enabled = "fcitx";
    fcitx.engines = with pkgs.fcitx-engines; [ table-extra m17n ];
  };
  fonts.fonts = [ pkgs.noto-fonts pkgs.noto-fonts-cjk pkgs.noto-fonts-emoji pkgs.noto-fonts-extra pkgs.emacs-all-the-icons-fonts ];

  # Enable the X11 windowing system.
  services.xserver.enable = true;
  services.xserver.layout = "us";
  services.xserver.xkbOptions = "eurosign:e";

  services.xserver.displayManager.gdm.enable = true;
  services.xserver.desktopManager.gnome.enable = true;
  environment.gnome.excludePackages = [ pkgs.epiphany pkgs.gnome3.geary ];

  systemd.suppressedSystemUnits = [
      "hibernate.target"
      "suspend.target"
      "suspend-then-hibernate.target"
      "sleep.target"
      "hybrid-sleep.target"
      "systemd-hibernate.service"
      "systemd-hybrid-sleep.service"
      "systemd-suspend.service"
      "systemd-suspend-then-hibernate.service"
  ];

  hardware.bluetooth.enable = true;

  programs.fish.enable = true;
  programs.fish.promptInit = ''
    any-nix-shell fish --info-right | source
  '';
  users.mutableUsers = false;
  users.defaultUserShell = pkgs.fish;
  users.extraGroups.plugdev = { };
  users.extraUsers = import ./common-users.nix { inherit pkgs; };
  security.sudo.wheelNeedsPassword = false;
  services.udev.packages = [ m-labs.openocd ];
  services.udev.extraRules = (import ./extra-udev.nix);

  nix.binaryCachePublicKeys = ["nixbld.m-labs.hk-1:5aSRVA5b320xbNvu30tqxVPXpld73bhtOeH6uAjRyHc="];
  nix.binaryCaches = ["https://nixbld.m-labs.hk" "https://cache.nixos.org"];
  nix.sandboxPaths = ["/opt"];

  nix.package = pkgs.nixUnstable;
  nix.extraOptions = ''
    experimental-features = nix-command flakes
  '';

  # This value determines the NixOS release with which your system is to be
  # compatible, in order to avoid breaking some software such as database
  # servers. You should change this only after NixOS release notes say you
  # should.
  system.stateVersion = "19.03"; # Did you read the comment?
}