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

let
  cfg = config.homelab.apps.arr;

  networkName = "arrStack";
  proxyNet = config.homelab.apps.traefik.sharedNetworkName;

  appNames = [ "bazarr" "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 = let
    mkAppOption = appName: {
      enable = lib.mkEnableOption "${appName} using Docker";
      exposePorts = lib.mkOption {
        type = lib.types.bool;
        description = "Expose ${appName} port";
        default = cfg.exposePorts;
      };
    };
  in {
    enable = lib.mkEnableOption "Arr Stack using Docker";
    exposePorts = lib.mkOption {
      type = lib.types.bool;
      description = "Expose all app ports";
      # Only expose ports by default if Traefik is not in use.
      default = ! config.homelab.apps.traefik.enable;
    };

    bazarr = mkAppOption "Bazarr";
    prowlarr = mkAppOption "Prowlarr";
    qbittorrent = mkAppOption "qBittorrent";
    radarr = mkAppOption "Radarr";
    sonarr = mkAppOption "Sonarr";
  };

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

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

      fileSystems.media.video = {
        enable = true;
        permissions = [ "read" "write" ];
      };

      virtualisation.containers.enable = lib.mkIf inUse true;
    };

    homelab.nfsMounts = let
      hugoBackup = "192.168.0.11:/mnt/BIG/BACKUP";
      arrOptions = [
        "auto"
        "rsize=1048576" "wsize=1048576"
        "hard"
        "timeo=600" "retrans=2"
        "_netdev"
      ];
      mkMount = device: {
        inherit device;
        extraOptions = arrOptions;
      };
    in lib.mkIf inUse {
      "/srv/bazarr-backup" = lib.mkIf cfg.bazarr.enable (mkMount "${hugoBackup}/BAZARR");
      "/srv/prowlarr-backup" = lib.mkIf cfg.bazarr.enable (mkMount "${hugoBackup}/PROWLARR");
      "/srv/qbittorrent" = lib.mkIf cfg.qbittorrent.enable (mkMount "192.168.0.11:/mnt/SMALL/CONFIG/QBITTORRENT");
      "/srv/radarr-backup" = lib.mkIf cfg.radarr.enable (mkMount "${hugoBackup}/RADARR");
      "/srv/sonarr-backup" = lib.mkIf cfg.sonarr.enable (mkMount "${hugoBackup}/SONARR");
      "/srv/torrent" = mkMount "192.168.0.11:/mnt/SMALL/MEDIA/TORRENT";
    };

    # Make sure the Docker network exists.
    homelab.dockerNetworks."${networkName}" = lib.mkIf inUse {
      requiredBy = [
        "docker-bazarr.service"
        "docker-prowlarr.service"
        "docker-qbittorrent.service"
        "docker-radarr.service"
        "docker-sonarr.service"
      ];
    };

    # Create a user for each app.
    homelab.appUsers = let
      mkUser = uid: {
        inherit uid;
        group = config.users.groups.media.name;
      };
    in {
      bazarr = lib.mkIf cfg.bazarr.enable (mkUser 3003);
      prowlarr = lib.mkIf cfg.prowlarr.enable (mkUser 3004);
      qbittorrent = lib.mkIf cfg.qbittorrent.enable ((mkUser 3005) // {
        extraGroups = [ config.users.groups.apps.name ];
      });
      radarr = lib.mkIf cfg.radarr.enable (mkUser 3006);
      sonarr = lib.mkIf cfg.sonarr.enable (mkUser 3007);
    };

    homelab.traefikRouters = {
      bazarr = lib.mkIf cfg.bazarr.enable {
        rule = "Host(`bazarr.depeuter.dev`)";
        port = 6767;
      };
      prowlarr = lib.mkIf cfg.prowlarr.enable {
        rule = "Host(`prowlarr.depeuter.dev`)";
        port = 9696;
      };
      qbittorrent = lib.mkIf cfg.qbittorrent.enable {
        rule = "Host(`qb.depeuter.dev`)";
        port = 10095;
      };
      radarr = lib.mkIf cfg.radarr.enable {
        rule = "Host(`radarr.depeuter.dev`)";
        port = 7878;
      };
      sonarr = lib.mkIf cfg.sonarr.enable {
        rule = "Host(`sonarr.depeuter.dev`)";
        port = 8989;
      };
    };

    virtualisation.oci-containers.containers = let
      videoHostPath = config.homelab.fileSystems.media.video.hostPath;
    in {
      bazarr = let
        port = 6767;
      in lib.mkIf cfg.bazarr.enable {
        hostname = "bazarr";
        image = "ghcr.io/hotio/bazarr:release-1.5.2";
        autoStart = true;
        ports = lib.mkIf cfg.bazarr.exposePorts [
          "${toString port}:${toString port}/tcp"
          "${toString port}:${toString port}/udp"
        ];
        extraOptions = [
          "--network=${networkName}"
          "--network=${proxyNet}"
        ];
        environment = {
          PUID = toString config.users.users.bazarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
          WEBUI_PORTS = "${toString port}/tcp,${toString port}/udp";
        };
        volumes = [
          "bazarr-config:/config"

          "/srv/bazarr-backup:/config/backup"

          "${videoHostPath}/Films:/media/movies"
          "${videoHostPath}/Series:/media/series"
        ];
      };

      prowlarr = let
        port = 9696;
      in lib.mkIf cfg.prowlarr.enable {
        hostname = "prowlarr";
        image = "ghcr.io/hotio/prowlarr:release-2.0.5.5160";
        autoStart = true;
        ports = lib.mkIf cfg.prowlarr.exposePorts [
          "${toString port}:${toString port}/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"
          "--network=${proxyNet}"
        ];
        environment = {
          PUID = toString config.users.users.prowlarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          "prowlarr-config:/config"

          "/srv/prowlarr-backup:/config/Backups"
        ];
      };

      qbittorrent = let
        port = 10095;
      in lib.mkIf cfg.qbittorrent.enable {
        hostname = "qbittorrent";
        image = "ghcr.io/hotio/qbittorrent:release-5.1.2";
        autoStart = true;
        ports = lib.mkIf cfg.qbittorrent.exposePorts [
          "${toString port}:${toString port}/tcp"
          "${toString port}:${toString port}/udp"
        ];
        extraOptions = [
          "--network=${networkName}"
          "--network=${proxyNet}"
        ];
        environment = {
          PUID = toString config.users.users.qbittorrent.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
          WEBUI_PORTS = "${toString port}/tcp,${toString port}/udp";
        };
        volumes = [
          "/srv/qbittorrent:/config"

          "/srv/torrent:/media/cache"
        ];
      };

      radarr = let
        port = 7878;
      in lib.mkIf cfg.radarr.enable {
        hostname = "radarr";
        image = "ghcr.io/hotio/radarr:testing-5.28.0.10205";
        autoStart = true;
        ports = lib.mkIf cfg.radarr.exposePorts [
          "${toString port}:${toString port}/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"
          "--network=${proxyNet}"
        ];
        environment = {
          PUID = toString config.users.users.radarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          "radarr-config:/config"

          "/srv/radarr-backup:/config/Backups"

          "/srv/torrent:/media/cache"
          "${videoHostPath}/Films:/media/movies"
        ];
      };

      sonarr = let
        port = 8989;
      in lib.mkIf cfg.sonarr.enable {
        hostname = "sonarr";
        image = "ghcr.io/hotio/sonarr:release-4.0.15.2941";
        autoStart = true;
        ports = lib.mkIf cfg.sonarr.exposePorts [
          "${toString port}:${toString port}/tcp"
        ];
        extraOptions = [
          "--network=${networkName}"
          "--network=${proxyNet}"
        ];
        environment = {
          PUID = toString config.users.users.sonarr.uid;
          inherit PGID UMASK;
          TZ = config.time.timeZone;
        };
        volumes = [
          "sonarr-config:/config"

          "/srv/sonarr-backup:/config/Backups"

          "/srv/torrent:/media/cache"
          "${videoHostPath}/Series:/media/series"
        ];
      };
    };
  };
}