{
  config,
  lib,
  pkgs,
  namespace,
  ...
}:
{
  programs.ccache = {
    enable = true;
    packageNames = [
      "cachyos-lto"
      "cachyos-lto-x86_64-unknown-linux-gnu-6.18.0"
      "cachyos-lto-x86_64-unknown-linux-gnu"
      "cachyos-lto-znver4"
      "cachyos-server-lto"
      "cachyos-server-lto-znver4"
      "cachyos-rc-lto"
      "cachyos-rc-lto-znver4"
      # "chromium"
      "dolphin-emu"
      "electron"
      # "ffmpeg"
      "ffmpeg_7"
      "ffmpeg_6"
      "ffmpeg-full"
      "gamescope"
      "gjs"
      "gst-plugins-bad"
      "gst-plugins-rs"
      "gtk4"
      "jemalloc"
      "jupiter-fan-control"
      "libcamera-rpi"
      "libraspberrypi"
      "libsecret"
      "linux"
      "linuxPackages_cachyos"
      "linuxPackages_cachyos-lto"
      "linuxPackages_rpi4"
      "linuxPackages_rpi5"
      "mesa"
      "mesa-radeonsi-jupiter"
      "mgba"
      "onnxruntime"
      "opencv"
      "pipewire"
      "qemu"
      "qemu_kvm"
      "qemu_full"
      "qt3d"
      "qtdeclarative"
      "qtmultimedia"
      "raspberrypi-utils"
      "ryubing"
      "sdl"
      "sdl2"
      "sdl3"
      "torch"
      "uv"
      "webkitgtk"
    ];
    cacheDir = "/var/cache/ccache";  # default location
  };

  nixpkgs.overlays = [
    (self: super: {
      "linux_rpi-bcm2711" = super."linux_rpi-bcm2711".override { stdenv = super.ccacheStdenv; };
    })
    (self: super: {
      "mesa" = super."mesa".override { buildPackages.stdenv = super.ccacheStdenv; };
    })
    (self: super: {
      "webkitgtk_4_1" = super.stable."webkitgtk_4_1".override { clangStdenv = super.ccacheStdenv; };
    })
    (self: super: {
      "webkitgtk_6_0" = super."webkitgtk_6_0".override { clangStdenv = super.ccacheStdenv; };
    })
    (self: super: {
      "jellyfin-ffmpeg" = super."jellyfin-ffmpeg".override { ffmpeg_7-full = super.ffmpeg_7-full.override { stdenv = super.ccacheStdenv; }; };
    })
    # (self: super: {
    #   "ffmpeg-headless-rpi" = super."ffmpeg-headless-rpi".override { ffmpeg = super.ffmpeg_7.override { stdenv = super.ccacheStdenv; }; };
    # })

    # todo: make these work
    (self: super: {
      pcsx2 = super.pcsx2.override {
        llvmPackages = super.llvmPackages // {
          stdenv = super.ccacheStdenv;
        };
      };
    })
    (self: super: {
      driversi686Linux = super.driversi686Linux // {
        mesa = super.driversi686Linux.mesa.override { stdenv = super.ccacheStdenv; buildPackages.stdenv = super.ccacheStdenv; };
      };
    })
    (self: super: {
      kdePackages = super.kdePackages // {
        qt3d = super.kdePackages.qt3d.override { qtbase = super.kdePackages.qtbase.override { stdenv = super.ccacheStdenv; }; };
        # qtbase = super.kdePackages.qtbase.override { stdenv = super.ccacheStdenv; };
        qtwebengine = super.kdePackages.qtwebengine.override { stdenv = super.ccacheStdenv; };
      };
    })
    (self: super: {
      linuxAndFirmware = super.linuxAndFirmware // {
        linuxPackages_rpi4 = super.linuxAndFirmware.linuxPackages_rpi4.override { stdenv = super.ccacheStdenv; };
      };
    })
  ];

  nix = {
    settings = {
      extra-sandbox-paths = [ config.programs.ccache.cacheDir ];
      substituters = [
        "https://cache.mjallen.dev/nas-cache"
        "https://nixos-raspberrypi.cachix.org"
        "https://nix-community.cachix.org"
        "https://cache.nixos.org/"
      ];
      trusted-public-keys = [
        "nas-cache:Y7PR+XTLr1bLIL85PKb9Tk9/BnE5HndTKvZYWVP1/48="
        "nixos-raspberrypi.cachix.org-1:4iMO9LXa8BqhU+Rpg6LQKiGa2lsNh/j2oiYLNOQ5sPI="
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      ];
      warn-dirty = lib.mkForce false;
      experimental-features = lib.mkForce [
        "nix-command"
        "flakes"
      ];
      trusted-users = [ "@wheel" ];
    };

    # Garbage collect automatically every week
    gc.automatic = lib.mkDefault true;
    gc.options = lib.mkDefault "--delete-older-than 30d";

    optimise.automatic = lib.mkDefault true;
  };

  nixpkgs = {
    config = {
      cudaSupport = lib.mkDefault config.${namespace}.hardware.nvidia.enable;
      rocmSupport = lib.mkDefault config.${namespace}.hardware.amd.enable;
      allowUnsupportedSystem = true;
    };
  };
}