nixos/pkgsets/emacs/transmission.nix

{
  config,
  lib,
  pkgs,
  ...
}:
with lib;
  mkIf (elem "emacs::transmission" config.machine.pkgs) {
    programs.emacs.init.usePackage = {
      transmission = {
        enable = true;
        defer = true;
        command = ["transmission"];
        bindLocal = {
          transmission-mode-map = {
            "A" = ''              (lambda ()
                                 (interactive)
                                 (transmission-add (read-string "Magnet URI: ")))'';
          };
        };
        config = ''
          ;; Auto refresh for all transmission buffers
          (setq transmission-refresh-modes '(transmission-mode
                                             transmission-files-mode
                                             transmission-info-mode
                                             transmission-peers-mode))

          (defun transmission ()
            "Open a `transmission-mode' buffer."
            (interactive)
            (let* ((name "*transmission*")
                   (buffer (or (get-buffer name)
                               (generate-new-buffer name))))
              (transmission-turtle-poll)
              (unless (eq buffer (current-buffer))
                (with-current-buffer buffer
                  (unless (eq major-mode 'transmission-mode)
                    (condition-case e
                        (progn
                          (transmission-mode)
                          (revert-buffer)
                          (goto-char (point-min)))
                      (error
                       (kill-buffer buffer)
                       (signal (car e) (cdr e))))))
                (switch-to-buffer buffer))))
        '';
      };
    };
  }