# services/selkies.nix — Guild Wars in a browser via Selkies
#
# Replaces the Neko attempt (services/neko.nix, now unimported): Neko's
# absolute-pointer input model can't handle Guild Wars' exclusive mouse grab.
# Selkies captures the mouse client-side with the browser Pointer Lock API and
# sends *relative* movement, so the grab is a non-issue — and it uses the GPU
# (NVENC + EGL) instead of software rendering.
#
# Reach it at selkies.nordhammer.it (Authelia-gated). The Wine prefix with
# Guild Wars already installed is reused from the old Neko home, seeded into
# /var/lib/selkies/home/.wine (see the deploy note in the repo).
{ config, pkgs, lib, ... }:
let
  # Selkies' NVIDIA EGL desktop (Ubuntu 24.04) plus Wine for the 32-bit GW
  # client. Built from stdin (no build context); see neko.nix for the why.
  dockerfile = pkgs.writeText "selkies-gw.Dockerfile" ''
    FROM ghcr.io/selkies-project/nvidia-egl-desktop:24.04
    USER root
    RUN add-apt-repository -y multiverse \
     && dpkg --add-architecture i386 \
     && apt-get update \
     && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
          wine wine32 wine64 winbind cabextract ca-certificates wget \
     && rm -rf /var/lib/apt/lists/*
    # `gw` launcher: GW is 32-bit, so it needs the 32-bit NVIDIA GL libs (mounted
    # at /usr/lib/i386-linux-gnu/nvidia by the service) on the loader path, and
    # VirtualGL (EGL backend) to render on the M2000. Without this GW falls back
    # to llvmpipe (software) and pegs ~18 CPU cores at <20 fps.
    RUN printf '#!/bin/bash\nexport LD_LIBRARY_PATH=/usr/lib/i386-linux-gnu/nvidia\nexport VGL_DISPLAY=egl VGL_FPS=60\ncd "$HOME/.wine/drive_c/Program Files (x86)/Guild Wars/"\nexec vglrun wine Gw.exe "$@"\n' > /usr/local/bin/gw \
     && chmod +x /usr/local/bin/gw
    USER 1000
  '';
in
{
  config = lib.mkIf (config.networking.hostName == "FredOS-Mediaserver") {

    virtualisation.docker.enable = true;
    # GPU into the container via CDI (nvidia.com/gpu=all). The CDI spec only
    # carries the 64-bit driver libs, so the 32-bit set (for 32-bit Wine/GW) is
    # bind-mounted separately below; enable32Bit makes them exist on the host.
    hardware.nvidia-container-toolkit.enable = true;
    hardware.graphics.enable32Bit = true;

    systemd.tmpfiles.rules = [
      "d /var/lib/selkies      0755 root root -"
      # Container user is uid/gid 1000 and must own its home.
      "d /var/lib/selkies/home 0755 1000 1000 -"
    ];

    systemd.services.selkies = {
      description = "Selkies — Guild Wars in a browser (EGL desktop + Wine + NVENC)";
      after = [ "docker.service" "network-online.target" ];
      requires = [ "docker.service" ];
      wants = [ "network-online.target" ];
      wantedBy = [ "multi-user.target" ];

      startLimitIntervalSec = 600;
      startLimitBurst = 3;

      serviceConfig = {
        Restart = "on-failure";
        RestartSec = "30s";
        TimeoutStartSec = "3600";
        ExecStartPre = [
          "-${pkgs.docker}/bin/docker rm -f selkies"
          "${pkgs.writeShellScript "selkies-build" ''
            exec ${pkgs.docker}/bin/docker build -t selkies-gw:local - < ${dockerfile}
          ''}"
        ];
        ExecStart = pkgs.writeShellScript "selkies-run" ''
          exec ${pkgs.docker}/bin/docker run --rm --name selkies \
            --device=nvidia.com/gpu=all \
            -e NVIDIA_VISIBLE_DEVICES=all \
            -e NVIDIA_DRIVER_CAPABILITIES=all \
            --shm-size=2g \
            -p 127.0.0.1:8093:8080 \
            -p 3478:3478 -p 3478:3478/udp \
            -p 65532-65535:65532-65535/udp \
            -e TZ=Europe/Stockholm \
            -e DISPLAY_SIZEW=1280 -e DISPLAY_SIZEH=720 \
            -e DISPLAY_REFRESH=60 -e DISPLAY_DPI=96 -e DISPLAY_CDEPTH=24 \
            -e PASSWD=selkies \
            -e SELKIES_ENCODER=nvh264enc \
            -e SELKIES_VIDEO_BITRATE=8000 \
            -e SELKIES_FRAMERATE=60 \
            -e SELKIES_ENABLE_BASIC_AUTH=false \
            -e SELKIES_TURN_HOST=10.0.0.1 \
            -e SELKIES_TURN_PROTOCOL=udp \
            -e SELKIES_TURN_PORT=3478 \
            -e TURN_MIN_PORT=65532 -e TURN_MAX_PORT=65535 \
            -v ${config.hardware.nvidia.package.lib32}/lib:/usr/lib/i386-linux-gnu/nvidia:ro \
            -v /var/lib/selkies/home:/home/ubuntu \
            selkies-gw:local
        '';
        ExecStop = "${pkgs.docker}/bin/docker stop selkies";
      };
    };
  };
}