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

let
  network = import ./network.nix;
  isVM = config.ptw.system.isVM;
  wireless = config.ptw.system.wireless;
  primaryInterface = lib.attrByPath [ "ptw" "system" "primaryInterface" ] "" config;
in {
  time.timeZone = "Europe/Berlin";
  ostylk.nftables = {
    enable = true;

    tables.firewall = {
      family = "inet";
      chains = {
        non-libvirt.extraConfig = let
          deviceIPString = lib.concatStringsSep "," (with network; [
            miku nishimiya tamaki mashu taihou # ayame
          ]);
        in ''
            # Accept traffic from my devices
            ip saddr != { ${deviceIPString} } drop
          '';
        input.extraConfig = ''
            type filter hook input priority 0

            ct state { established, related } accept
            iif lo accept
            iif ${primaryInterface} goto non-libvirt
          '';
      };
    };
  };
  networking = {
    useDHCP = false; # Done by the network manager
    networkmanager.enable = true;

    #interfaces.*.useDHCP = false;
    
    hostName = config.ptw.system.hostName;
    hosts = lib.mkIf (!isVM) {
      "${network.miku}" = [ "miku.local" ];
      "${network.nishimiya}" = [ "nishimiya.local" ];
      #"${network.ayame}" = [ "ayame.local" ];
      "${network.tamaki}" = [ "tamaki.local" ];
      "${network.mashu}" = [ "mashu.local" ];
      "${network.taihou}" = [ "taihou.local" ];
    };
  };

  i18n.defaultLocale = "en_GB.UTF-8";
  console = {
    font = "Lat2-Terminus16";
    keyMap = "de";
  };

  users = {
    mutableUsers = false;

    extraUsers = {
      root = {
	      # Disable root login
	      hashedPassword = "*";
      };
    };
  };

  documentation.nixos.enable = false;
  
  environment = {
    systemPackages = with pkgs; [
      htop
      vim
      git # Otherwise we cannot install home-manager
      git-crypt
      gnupg
      python3

      # General utilities
      bandwhich bottom latencytop
      
      # RT scheduling
      rtkit
    ] ++ lib.optionals (!isVM) (with pkgs; [ gopass ]);

    sessionVariables = {
      # Prevent us from having to always type it out
      NIXOS_CONFIG = "/home/${config.ptw.system.singleUser}/Development/Personal/nixos-config/hosts/${config.networking.hostName}.nix";
    };
  };

  fonts.fonts = with pkgs; [
    # CJK fonts
    source-han-sans source-han-serif
    # Coding fonts
    source-code-pro
    # Icon fonts
    nerdfonts
  ];

  # We don't tolerate non-free software, except for Steam and Linux firmware
  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
    "firmwareLinuxNonfree" "microcodeAmd" "microcodeIntel"
    "steam" "steam-original" "steam-runtime"
    "discord" "minecraft"
  ];

  services = {
    # TODO: Is this correct? Maybe run once
    timesyncd.enable = false;

    # Everyone needs sound
    pipewire = {
      enable = true;
      pulse.enable = true;
      jack.enable = true;
      alsa.enable = true;
      alsa.support32Bit = true;
      /*
      config.pipewire = {
        "context.modules" = [
          {
            name = "libpipewire-module-rtkit";
            args = {};
            flags = [ "ifexists" "nofail" ];
          }
          { name = "libpipewire-module-protocol-native"; }
          { name = "libpipewire-module-client-node"; }
          { name = "libpipewire-module-adapter"; }
          { name = "libpipewire-module-metadata"; }

          {
            name = "libpipewire-module-filter-chain";
            args = {
              "node.name" = "effect_output.virtual-surround-7.1-hesuvi";
              "node.description" = "Virtual Surround Sink";
              "media.name" = "Virtual Surround Sink";
              "filter.graph" = {
                nodes = [
                  { type = "builtin"; label = "copy"; name = "copyFL"; }
                  { type = "builtin"; label = "copy"; name = "copyFR"; }
                  { type = "builtin"; label = "copy"; name = "copyFC"; }
                  { type = "builtin"; label = "copy"; name = "copyRL"; }
                  { type = "builtin"; label = "copy"; name = "copyRR"; }
                  { type = "builtin"; label = "copy"; name = "copySL"; }
                  { type = "builtin"; label = "copy"; name = "copySR"; }
                  { type = "builtin"; label = "copy"; name = "copyLFE"; }

                  { type = "builtin"; label = "convolver"; name = "convFL_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 0; }; }
                  { type = "builtin"; label = "convolver"; name = "convFL_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 1; }; }
                  { type = "builtin"; label = "convolver"; name = "convSL_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 2; }; }
                  { type = "builtin"; label = "convolver"; name = "convSL_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 3; }; }
                  { type = "builtin"; label = "convolver"; name = "convRL_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 4; }; }
                  { type = "builtin"; label = "convolver"; name = "convRL_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 5; }; }
                  { type = "builtin"; label = "convolver"; name = "convFC_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 6; }; }
                  { type = "builtin"; label = "convolver"; name = "convFR_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 7; }; }
                  { type = "builtin"; label = "convolver"; name = "convFR_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 8; }; }
                  { type = "builtin"; label = "convolver"; name = "convSR_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 9; }; }
                  { type = "builtin"; label = "convolver"; name = "convSR_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 10; }; }
                  { type = "builtin"; label = "convolver"; name = "convRR_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 11; }; }
                  { type = "builtin"; label = "convolver"; name = "convRR_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 12; }; }
                  { type = "builtin"; label = "convolver"; name = "convFC_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 13; }; }

                  { type = "builtin"; label = "convolver"; name = "convLFE_L"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 6; }; }
                  { type = "builtin"; label = "convolver"; name = "convLFE_R"; config = { filename = "hrir_hesuvi/hrir.wav"; channel = 13; }; }

                  { type = "builtin"; label = "mixer"; name = "mixL"; }
                  { type = "builtin"; label = "mixer"; name = "mixR"; }
                ];
                links = let
                  linkInput = channel: [
                    { output = "copy${channel}:Out"; input = "conv${channel}_L:In"; }
                    { output = "copy${channel}:Out"; input = "conv${channel}_R:In"; }
                  ];
                  linkOutput = channel: n: [
                    { output = "conv${channel}_L:Out"; input = "mix_L:In ${builtins.toString n}"; }
                    { output = "conv${channel}_R:Out"; input = "mix_R:In ${builtins.toString n}"; }
                  ];
                in (builtins.concatMap (channel: linkInput channel) [ "FL" "SL" "RL" "FC" "FR" "SR" "RR" "LFE" ])
                   ++ [
                     (linkOutput "FL" 1)
                     (linkOutput "SL" 2)
                     (linkOutput "RL" 3)
                     (linkOutput "FC" 4)
                     (linkOutput "FR" 5)
                     (linkOutput "SR" 6)
                     (linkOutput "RR" 7)
                     (linkOutput "LFE" 8)
                   ];
                inputs = builtins.map (channel: "copy${channel}:In") [ "FL" "SL" "RL" "FC" "FR" "SR" "RR" "LFE" ];
                outputs = [ "mixL:Out" "mixR:Out" ];
              };

              "capture.props" = {
                "media.class" = "Audio/Sink";
                "audio.channels" = 8;
                "audio.position" = [ "FL" "FR" "FC" "LFE" "RL" "RR" "SL" "SR" ];
              };
              "playback.props" = {
                "node.passive" = true;
                "audio.channels" = 2;
                "audio.positions" = [ "FL" "FR" ];
              };
            };
          }
        ];
      };
      */
    };

    # On desktop: Monitor keyboards, mice, ...
    # On portable devices: Monitor their battery
    upower.enable = true;

    # What generated entropy?
    #haveged.enable = true;
    
    printing.enable = lib.mkDefault false;
    avahi.enable = false;

    # For debugging.
    # TODO: Lock to known IPs and keys
    sshd.enable = true;

    # Prevent unexpected OOM situations with heavy swapping
    earlyoom = {
      enable = true;
      enableNotifications = true;
    };
  };

  # Don't wait for a network connection
  systemd.services.NetworkManager-wait-online.enable = false;
  
  security.sudo.extraConfig = ''
      Defaults env_keep += "NIXOS_CONFIG"
    '';

  hardware = {
    enableRedistributableFirmware = true;
    # This is a Pipewire household!
    pulseaudio.enable = false;

    opengl = {
      enable = true;
      driSupport32Bit = true;
      driSupport = true;
      extraPackages = with pkgs; [ vaapiVdpau libvdpau-va-gl ];
    };

    # Only a subset of my devices have bluetooth
    bluetooth = lib.mkIf wireless {
      enable = true;
    };
  };

  nix = {
    package = pkgs.nixUnstable;
    extraOptions = ''
      experimental-features = nix-command flakes
    '';
    registry = {
      nixpkgs.flake = inputs.nixpkgs;
    };
    settings = {
      substituters = [
        "https://cache.nixos.org/" # Official binary substitute
        "https://nix-community.cachix.org/" # For emacsGccPgtk
      ];
      trusted-public-keys = [
        "hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs=" # Official binary substitute
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=" # nix-community
      ];
    };
  };
  
  boot = {
    cleanTmpDir = true;
    loader =  {
      systemd-boot.enable = true;
      efi.canTouchEfiVariables = true;
    };
  };

  system.stateVersion = "21.05";
}