{ config, lib, pkgs, ... }:
with lib;
let
  cfg = config.gonic;
in
{
  options = {
    gonic = {
      enable = mkEnableOption "enable gonic configuration";

      listenAddr = mkOption {
        type = types.str;
        default = "127.0.0.1:4747";
        description = ''
          Address that gonic will listen on.
        '';
      };

      extraGroups = mkOption {
        type = types.listOf (types.str);
        default = [];
        description = ''
          Additional groups for gonic.
        '';
      };
      
      musicPaths = mkOption {
        type = types.listOf (types.str);
        description = ''
          Directories with music in it.
        '';
      };

      podcastsPath = mkOption {
        type = types.str;
        default = "${cfg.stateDir}/podcasts";
        description = ''
          Directory for podcasts.
        '';
      };

      playlistsPath = mkOption {
        type = types.str;
        default = "${cfg.stateDir}/playlists";
        description = ''
          Directory for playlists.
        '';
      };

      stateDir = mkOption {
        type = types.str;
        default = "/var/lib/gonic";
        description = ''
          A directory where gonic will keep their files.
        '';
      };

      settings = mkOption {
        default = {};
        description = ''
          Additional gonic settings
        '';
      };
    };
  };

  config = mkIf cfg.enable {
    nixpkgs.overlays = [
      (final: prev: {
        ffmpeg = prev.ffmpeg-headless;
      })
    ];

    systemd.services.gonic.serviceConfig = {
      SupplementaryGroups = cfg.extraGroups;
    };

    systemd.tmpfiles.rules = [
      "d ${cfg.stateDir} 0755 nobody nogroup"
      "d ${cfg.podcastsPath} 0755 nobody nogroup"
      "d ${cfg.playlistsPath} 0755 nobody nogroup"
    ];

    services.gonic = {
      enable = true;
      settings = {
        listen-addr = cfg.listenAddr;
        music-path = cfg.musicPaths;
        playlists-path = [cfg.podcastsPath];
        podcast-path = [cfg.playlistsPath];
        db-path = ["${cfg.stateDir}/gonic.db"];
      } // cfg.settings;
    };
  };
}