{ config, lib, ... }:

with lib;
let


  cfg = config.services.custom.transmission;

in {


  options.services.custom.transmission = {
    enable = lib.mkEnableOption "transmission";
    home = lib.mkOption {
      type        = lib.types.path;
      description = "where the configs are";
    };
    store  = lib.mkOption {
      type        = lib.types.path;
      description = "where to store";
    };
    hosts = lib.mkOption {
      type        = lib.types.str;
      description = "allowed hostnames";
    };
    whitelist = lib.mkOption {
      type        = lib.types.str;
      description = "Ip to listen to";
    };
    user = lib.mkOption {
      type        = lib.types.str;
      description = "user to login";
    };
    password = lib.mkOption {
      type        = lib.types.str;
      description = "password to login";
    };
    port = mkOption {
      type = with types; int;
      default = 51413;
      description = ''
        forwarded Port
      '';
    };
  };

  config = lib.mkIf cfg.enable {

    # because 2.94 is not supported by pass the popcorn
    #nixpkgs.config.packageOverrides = pkgs: {
    #  transmission =
    #  (pkgs.transmission.overrideAttrs (old: rec {
    #    version = "2.93";
    #    src = pkgs.fetchurl {
    #     url    = "https://github.com/transmission/transmission-releases/raw/master/transmission-2.93.tar.xz";
    #     sha256 = "02xrp49gsv4jkbzp37qrwlnb9nlja08s92dyvgdbr6a4187945c8";
    #    };
    #  }));
    #};

    services.transmission = {
      enable = true;
      home   = "${cfg.home}";
      settings = {

        # Downloads
        download-dir           = "${cfg.store}/downloads";
        incomplete-dir-enabled = true;
        incomplete-dir         = "${cfg.store}/incomplete";

        # RPC = UI connection
        rpc-whitelist          = "${cfg.whitelist}";
        rpc-host-whitelist     = "${cfg.hosts}";
        rpc-user               = "${cfg.user}";
        rpc-username           = "${cfg.user}";
        rpc-password           = "${cfg.password}";

        # Start torrents as soon as they are added
        start-added-torrents   = true;

        # Encryption may help get around some ISP filtering,
        # but at the cost of slightly higher CPU use.
        # 0 = Prefer unencrypted connections,
        # 1 = Prefer encrypted connections,
        # 2 = Require encrypted connections; default = 1)
        encryption = 2;

        # Enable Local Peer Discovery (LPD).
        lpd-enabled              = true;

        # Enable UPnP or NAT-PMP.
        peer-port = cfg.port;
        port-forwarding-enabled  = true;

        # "normal" speed limits
        speed-limit-down-enabled = true;
        speed-limit-down         = 800;
        speed-limit-up-enabled   = true ;
        speed-limit-up           = 50;
        upload-slots-per-torrent = 8;

        # Queuing
        # When true, Transmission will only download
        # download-queue-size non-stalled torrents at once.
        download-queue-enabled   = true;
        download-queue-size      = 1;

        # When true, torrents that have not shared data for
        # queue-stalled-minutes are treated as 'stalled'
        # and are not counted against the queue-download-size
        # and seed-queue-size limits.
        queue-stalled-enabled    = true;
        queue-stalled-minutes    = 60;

        # When true. Transmission will only seed seed-queue-size
        # non-stalled torrents at once.
        seed-queue-enabled       = true;
        seed-queue-size          = 10;

        # umask of the moves that got downloaded
        umask = 18;

      };
    };

  };
}