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

with lib;
let
  cfg = config.services.brook;
in
{
  options.services.brook.dash = {
    enable = mkEnableOption "ffmpeg dash server";

    name = mkOption {
      type = types.str;
      description = ''
        The name of the rtmp endpoint of the stream.  This might show up as
        metadata in some clients
      '';
    };
  };

  config = mkIf cfg.dash.enable {
    systemd.services.brook-ffmpeg = {
      wantedBy = [ "multi-user.target" ];
      after = [ "network.target" ];
      
      serviceConfig = {
        StateDirectory = "dash";
        Group = "nginx";
      };
      
      script = let
        ffmpeg = "${pkgs.ffmpeg}/bin/ffmpeg";
      in
        ''
          ${ffmpeg}-listen 1 -i rtmp://0.0.0.0:1935/${cfg.dash.name}/live \
            -c:v libx264 -x264opts "keyint=24:min-keyint=24:no-scenecut" -r 24 \
            -c:a aac -b:a 128k \
            -bf 1 -b_strategy 0 -sc_threshold 0 -pix_fmt yuv420p \
            -map 0:v:0 -map 0:a:0 -map 0:v:0 \
            -map 0:a:0 -map 0:v:0 -map 0:a:0 \
            /var/lib/dash/live.mpd
        '';
    };
  };
}