{ config, lib, ... }:

with lib;

mkIf (elem "emacs::elpy" config.machine.pkgs) {
  programs.emacs.init.usePackage.elpy = {
    enable = true;
    after = [ "python" ];
    command = [ "elpy-enable" ];
    hook = [ ''
               (elpy-mode
                 . (lambda ()
                   (set (make-local-variable 'company-backends)
                        '((company-dabbrev-code company-yasnippet elpy-company-backend)))))
           '' ]
           ++ (optional (elem "emacs::flyspell" config.machine.pkgs) "(elpy-mode . (lambda () (flyspell-prog-mode)))")
           ++ (optional (elem "emacs::flycheck" config.machine.pkgs) "(elpy-mode . (lambda () (flycheck-mode)))");
    bindLocal = { elpy-mode-map = {
      "<tab>" = "company-indent-or-complete-common";
    };};
    init = ''(with-eval-after-load 'python (elpy-enable))'';
    config = ''
      (setq elpy-project-root-finder-functions '(elpy-project-find-git-root elpy-project-find-python-root elpy-project-find-hg-root elpy-project-find-svn-root))
      (setq elpy-rpc-backend "jedi")
      (setq python-shell-interpreter "ipython"
            python-shell-interpreter-args "-i --simple-prompt")

      ${optionalString (elem "emacs::flycheck" config.machine.pkgs) ''
        ;; manually set what python-mypy is and configure it to ignore 3rd party imports
        (setq elpy-modules (delq 'elpy-module-flymake elpy-modules))
        (setq-default flycheck-checker 'python-pylint)
        (flycheck-add-next-checker  'python-pylint 'python-mypy t)
        (flycheck-add-next-checker 'python-mypy 'python-flake8 t)''}
    '';
  };
}