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

let
  cfg = config.homelab.apps.arr;

  networkName = "arrStack";
  appNames = [ "bazarr" "lidarr" "prowlarr" "qbittorrent" "radarr" "sonarr" ];
  inUse = builtins.any (app: cfg.${app}.enable) appNames;

  PGID = toString config.users.groups.media.gid;
  UMASK = "002";
in {
  options.homelab.apps.arr = {
    enable = lib.mkEnableOption "Arr Stack using Docker";

    bazarr.enable = lib.mkEnableOption "Bazarr using Docker";
    lidarr.enable = lib.mkEnableOption "Lidarr using Docker";
    prowlarr.enable = lib.mkEnableOption "Prowlarr using Docker";
    qbittorrent.enable = lib.mkEnableOption "qBittorrent using Docker";
    radarr.enable = lib.mkEnableOption "Radarr using Docker";
    sonarr.enable = lib.mkEnableOption "Sonarr using Docker";
  };

  config = {
    homelab = {
      users.media.enable = lib.mkIf inUse true;

      # "Master switch": Enable all apps.
      apps.arr = {
        bazarr.enable = lib.mkIf cfg.enable true;
        lidarr.enable = lib.mkIf cfg.enable true;
        prowlarr.enable = lib.mkIf cfg.enable true;
        qbittorrent.enable = lib.mkIf cfg.enable true;
        radarr.enable = lib.mkIf cfg.enable true;
        sonarr.enable = lib.mkIf cfg.enable true;
      };
    };

    fileSystems = lib.mkIf inUse {
      "/srv/video" = {
        device = "192.168.0.11:/mnt/SMALL/MEDIA/VIDEO";
        fsType = "nfs";
        options = [
          "rw"
          "nfsvers=4.2"
          "async" "soft"
          "timeo=100" "retry=50" "actimeo=1800" "lookupcache=all"
          "nosuid" "tcp"
        ];
      };

      "/srv/qbittorrent" = {
        device = "192.168.0.11:/mnt/SMALL/CONFIG/QBITTORRENT/qBittorrent";
        fsType = "nfs";
        options = [
          "rw"
          "nfsvers=4.2"
          "async" "soft"
          "nosuid" "tcp"
        ];
      };
    };

    # Make sure the Docker network exists.
    systemd.services."docker-${networkName}-create-network" = lib.mkIf inUse {
      description = "Create Docker network for ${networkName}";
      requiredBy = [
        "docker-bazarr.service"
        "docker-lidarr.service"
        "docker-prowlarr.service"
        "docker-qbittorrent.service"
        "docker-radarr.service"
        "docker-sonarr.service"
      ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
      };
      script = ''
        if ! ${pkgs.docker}/bin/docker network ls | grep -q ${networkName}; then
          ${pkgs.docker}/bin/docker network create ${networkName}
        fi
      '';
    };

    # Create a user for each app.
    users.users = {
      bazarr = lib.mkIf cfg.bazarr.enable {
        uid = lib.mkForce 3003;
        isSystemUser = true;
        group = config.users.groups.media.name;
        home = "/var/empty";
        shell = null;
      };
      lidarr = lib.mkIf cfg.lidarr.enable {
        uid = lib.mkForce 3002;
        isSystemUser = true;
        group = config.users.groups.media.name;
        home = "/var/empty";
        shell = null;
      };
      prowlarr = lib.mkIf cfg.prowlarr.enable {
        uid = lib.mkForce 3004;
        isSystemUser = true;
        group = config.users.groups.media.name;
        home = "/var/empty";
        shell = null;
      };
      qbittorrent = lib.mkIf cfg.qbittorrent.enable {
        uid = lib.mkForce 3005;
        isSystemUser = true;
        group = config.users.groups.media.name;
        home = "/var/empty";
        shell = null;
      };
      radarr = lib.mkIf cfg.radarr.enable {
        uid = lib.mkForce 3006;
        isSystemUser = true;
        group = config.users.groups.media.name;
        home = "/var/empty";
        shell = null;
      };
      sonarr = lib.mkIf cfg.sonarr.enable {
        uid = lib.mkForce 3007;
        isSystemUser = true;
        group = config.users.groups.media.name;
        home = "/var/empty";
        shell = null;
      };
    };

    virtualisation.oci-containers.containers = {
      bazarr = lib.mkIf cfg.bazarr.enable {
        hostname = "bazarr";
        image = "ghcr.io/hotio/bazarr:release-1.4.4";
        autoStart = true;
        ports = [
          "6767:6767/tcp"
          "6767:6767/udp"
        ];
        extraOptions = [
          "--network=${networkName}"

          "--mount" ''type=volume,source=bazarr-backup,target=/backup,volume-driver=local,volume-opt=type=nfs,volume-opt=device=:/mnt/BIG/BACKUP/BAZARR,"volume-opt=o=addr=192.168.0.11,rw,nfsvers=4.2,async,nosuid"''
        ];
        environment = {
          PUID = toString config.users.users.bazarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
          WEBUI_PORTS = "6767/tcp,6767/udp";
        };
        volumes = [
          "bazarr-config:/config"
          "/srv/video:/data"
        ];
      };

      lidarr = lib.mkIf cfg.lidarr.enable {
        hostname = "lidarr";
        image = "ghcr.io/hotio/lidarr:release-2.5.3.4341";
        autoStart = true;
        ports = [
          "8686:8686/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"

          "--mount" ''type=volume,source=lidarr-backup,target=/backup,volume-driver=local,volume-opt=type=nfs,volume-opt=device=:/mnt/BIG/BACKUP/LIDARR,"volume-opt=o=addr=192.168.0.11,rw,nfsvers=4.2,async,nosuid"''
        ];
        environment = {
          PUID = toString config.users.users.lidarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          "lidarr-config:/config"
          # TODO "data:/data"
        ];
      };

      prowlarr = lib.mkIf cfg.prowlarr.enable {
        hostname = "prowlarr";
        image = "ghcr.io/hotio/prowlarr:release-1.23.1.4708";
        autoStart = true;
        ports = [
          "9696:9696/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"
        ];
        environment = {
          PUID = toString config.users.users.prowlarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          # TODO "config:/config"
        ];
      };

      qbittorrent = lib.mkIf cfg.qbittorrent.enable {
        hostname = "qbittorrent";
        image = "ghcr.io/hotio/qbittorrent:release-4.6.7";
        autoStart = true;
        ports = [
          "10095:10095/udp"
          "10095:10095/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"

          "--mount" ''type=volume,source=torrents,target=/data,volume-driver=local,volume-opt=type=nfs,volume-opt=device=:/mnt/SMALL/MEDIA/TORRENT,"volume-opt=o=addr=192.168.0.11,rw,nfsvers=4.2,async,nosuid"''
        ];
        environment = {
          PUID = toString config.users.users.qbittorrent.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
          WEBUI_PORTS = "10095/tcp,10095/udp";
        };
        volumes = [
          "/srv/qbittorrent:/config/config"
          "/srv/video:/media/video"
        ];
      };

      radarr = lib.mkIf cfg.radarr.enable {
        hostname = "radarr";
        image = "ghcr.io/hotio/radarr:release-5.9.1.9070";
        autoStart = true;
        ports = [
          "7878:7878/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"
        ];
        environment = {
          PUID = toString config.users.users.radarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          # TODO "config:/config"
          # TODO "data:/data"
        ];
      };

      sonarr = lib.mkIf cfg.sonarr.enable {
        hostname = "sonarr";
        image = "ghcr.io/hotio/sonarr:release-4.0.9.2244";
        autoStart = true;
        ports = [
          "8989:8989/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"
        ];
        environment = {
          PUID = toString config.users.users.sonarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          # TODO "config:/config"
          # TODO "data:/data"
        ];
      };
    };
  };
}