{
  inputs,
  desktop ? false,
  hostname,
  self,
}:
{ pkgs, ... }:
let
  configure-gtk = pkgs.writeTextFile {
    name = "configure-gtk";
    destination = "/bin/configure-gtk";
    executable = true;
    text =
      let
        schema = pkgs.gsettings-desktop-schemas;
        datadir = "${schema}/share/gsettings-schemas/${schema.name}";
      in
      ''
        export XDG_DATA_DIRS=${datadir}:$XDG_DATA_DIRS
        gnome_schema=org.gnome.desktop.interface
        gsettings set $gnome_schema gtk-theme 'Breeze Dark'
      '';
  };

  theme = import "${self}/lib/theme" { inherit pkgs; };

  username = "opdavies";
in
{
  nixpkgs.config.allowUnfree = true;

  # Bootloader.
  boot = {
    loader = {
      systemd-boot = {
        enable = true;
        configurationLimit = 10;
      };

      efi = {
        canTouchEfiVariables = true;
        efiSysMountPoint = "/boot/efi";
      };
    };
  };

  services.thermald.enable = true;
  services.power-profiles-daemon.enable = false;

  services.tlp = {
    enable = true;

    settings = {
      PCIE_ASPM_ON_BAT = "powersupersave";
      CPU_SCALING_GOVERNOR_ON_AC = "performance";
      CPU_SCALING_GOVERNOR_ON_BAT = "powersave";
      CPU_MAX_PERF_ON_AC = "100";
      CPU_MAX_PERF_ON_BAT = "30";
      STOP_CHARGE_THRESH_BAT1 = "95";
      STOP_CHARGE_THRESH_BAT0 = "95";
    };
  };

  systemd.extraConfig = ''
    DefaultTimeoutStopSec=10s
  '';

  networking.hostName = hostname;

  # networking.wireless.enable = true;  # Enables wireless support via wpa_supplicant.

  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";

  # Enable networking
  networking.networkmanager.enable = true;

  # Set your time zone.
  time.timeZone = "Europe/London";

  # Select internationalisation properties.
  i18n.defaultLocale = "en_GB.UTF-8";

  i18n.extraLocaleSettings = {
    LC_ADDRESS = "en_GB.UTF-8";
    LC_IDENTIFICATION = "en_GB.UTF-8";
    LC_MEASUREMENT = "en_GB.UTF-8";
    LC_MONETARY = "en_GB.UTF-8";
    LC_NAME = "en_GB.UTF-8";
    LC_NUMERIC = "en_GB.UTF-8";
    LC_PAPER = "en_GB.UTF-8";
    LC_TELEPHONE = "en_GB.UTF-8";
    LC_TIME = "en_GB.UTF-8";
  };

  # Enable the X11 windowing system.
  services.xserver.enable = true;

  services.xserver = {
    xkb = {
      layout = "gb";
      variant = "";
    };
  };

  # Configure console keymap
  console.keyMap = "uk";

  services.avahi.enable = true;
  services.avahi.nssmdns4 = true;
  services.avahi.openFirewall = true;
  services.printing.enable = true;

  # Enable sound with pipewire.
  sound.enable = true;
  hardware.pulseaudio.enable = false;

  security = {
    polkit.enable = true;
    rtkit.enable = true;
  };

  services.pipewire = {
    enable = true;

    alsa = {
      enable = true;
      support32Bit = true;
    };

    pulse.enable = true;
  };

  # Enable touchpad support (enabled default in most desktopManager).
  # services.xserver.libinput.enable = true;

  users.users.${username} = {
    isNormalUser = true;
    description = "Oliver Davies";
    extraGroups = [
      "docker"
      "networkmanager"
      "wheel"
    ];
    packages = with pkgs; [ ];
  };

  security.sudo.wheelNeedsPassword = false;

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  environment.systemPackages =
    with pkgs;
    [
      ddev
      just
      mkcert
      mob
      simple-http-server
      ttyper
      yt-dlp
    ]
    ++ pkgs.lib.optionals desktop [
      acpi
      arandr
      brightnessctl
      configure-gtk
      dunst
      ffmpegthumbnailer
      libnotify
      obsidian
      pocket-casts
      rclone
      rclone-browser
      shotwell
      slack
      spotify
      teams-for-linux
      todoist-electron
      vscode
      xfce.thunar
      xfce.thunar-volman
      xfce.tumbler

      # Games.
      zeroad
    ];

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = {
  #   enable = true;
  #   enableSSHSupport = true;
  # };

  # List services that you want to enable:

  # Enable the OpenSSH daemon.
  services.openssh.enable = true;

  # Open ports in the firewall.
  networking.firewall.allowedTCPPorts = [
    9003 # xdebug
  ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  # networking.firewall.enable = false;

  # This value determines the NixOS release from which the default
  # settings for stateful data, like file locations and database versions
  # on your system were taken. It‘s perfectly fine and recommended to leave
  # this value at the release version of the first install of this system.
  # Before changing this value read the documentation for this option
  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
  system.stateVersion = "22.11"; # Did you read the comment?

  virtualisation.docker = {
    enable = true;

    autoPrune = {
      enable = true;
      dates = "weekly";
    };
  };

  programs.zsh.enable = true;
  programs.zsh.histSize = 5000;

  users.defaultUserShell = "/etc/profiles/per-user/${username}/bin/zsh";

  fonts = {
    fontconfig = {
      enable = true;
      defaultFonts = {
        monospace = [ theme.fonts.monospace.name ];
      };
    };

    packages =
      with pkgs;
      [
        (nerdfonts.override {
          fonts = [
            "AnonymousPro"
            "FiraCode"
            "GeistMono"
            "IntelOneMono"
            "Iosevka"
            "JetBrainsMono"
          ];
        })
      ]
      ++ [ theme.fonts.monospace.package ];
  };

  zramSwap.enable = true;

  nix = {
    gc = {
      automatic = true;
      dates = "daily";
      options = "--delete-older-than 7d";
    };

    optimise.automatic = true;

    settings = {
      auto-optimise-store = true;
      experimental-features = [
        "nix-command"
        "flakes"
      ];
      warn-dirty = false;
    };
  };

  # Make Caps lock work as an Escape key on press and Ctrl on hold.
  services.interception-tools =
    let
      dfkConfig = pkgs.writeText "dual-function-keys.yaml" ''
        MAPPINGS:
          - KEY: KEY_CAPSLOCK
            TAP: KEY_ESC
            HOLD: KEY_LEFTCTRL
      '';
    in
    {
      enable = true;
      plugins = pkgs.lib.mkForce [ pkgs.interception-tools-plugins.dual-function-keys ];
      udevmonConfig = ''
        - JOB: "${pkgs.interception-tools}/bin/intercept -g $DEVNODE | ${pkgs.interception-tools-plugins.dual-function-keys}/bin/dual-function-keys -c ${dfkConfig} | ${pkgs.interception-tools}/bin/uinput -d $DEVNODE"
          DEVICE:
            NAME: "AT Translated Set 2 keyboard"
            EVENTS:
              EV_KEY: [[KEY_CAPSLOCK, KEY_ESC, KEY_LEFTCTRL]]
      '';
    };

  system.autoUpgrade = {
    enable = true;
    flake = inputs.self.outPath;
    flags = [
      "--update-input"
      "nixpkgs"
      "--no-write-lock-file"
      "-L" # print build logs
    ];
    dates = "08:00";
    randomizedDelaySec = "45min";
  };

  services.gvfs.enable = true;

  programs.gnupg.agent = {
    enable = true;
    enableSSHSupport = true;
    pinentryPackage = pkgs.pinentry-qt;
  };

  programs.firefox = {
    enable = true;
    package = pkgs.firefox-wayland;
    languagePacks = [ "en-GB" ];
    preferences = {
      "intl.accept_languages" = "en-GB, en";
      "intl.regional_prefs.use_os_locales" = true;
    };
  };

  services.blueman.enable = true;

  services.cron = {
    enable = true;

    systemCronJobs = [ "* * * * * opdavies /home/${username}/.local/bin/notify-battery" ];
  };

  services.auto-cpufreq.enable = true;

  services.udev = {
    enable = true;
    extraRules = ''
      KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0660", GROUP="users", TAG+="uaccess", TAG+="udev-acl"
    '';
  };
}