;; REVIEW: Fix auto-mode: https://gitlab.com/emacs-guix/emacs-guix/issues/3.
(setq auto-mode-alist
      (delete '("/tmp/guix-build-\\(?:[-+._[:alnum:]]+\\)+\\.drv-[[:digit:]]+/environment-variables\\'" . guix-env-var-mode)
              auto-mode-alist))

;; REVIEW: Implement guix-store: https://gitlab.com/emacs-guix/emacs-guix/issues/2.
(require 'bui)
(require 'cl-lib)
(require 'guix-prettify)

(defun guix-store-prettify-path (path)
  (replace-regexp-in-string
   guix-prettify-regexp "/…"
   path))

(defun guix-store-kill-items ()
  "Delete marked items."
  (interactive)
  (let ((paths (or (bui-list-get-marked-id-list)
                   (list (bui-list-current-id)))))
    (when (yes-or-no-p (format "Delete %s? " (mapconcat 'guix-store-prettify-path paths" ")))
      (apply 'call-process "guix" nil nil nil "gc" "--delete" paths)
      (setq guix-store-cache (seq-difference guix-store-cache paths
                                             (lambda (item path)
                                               (string=
                                                (guix-store-item-path item)
                                                path))))
      (let ((old-point (point)))
        (revert-buffer nil t)
        (goto-char old-point)))))

(defvar guix-store-cache nil)

(cl-defstruct guix-store-item
  path
  status
  size)

(defun guix-store-item->entry (item)
  `((id . ,(guix-store-item-path item))
    (path . ,(guix-store-item-path item))
    (status . ,(guix-store-item-status item))
    (size . ,(guix-store-item-size item))))

(defun guix-store-build-cache (&optional live)
  "If LIVE is non-nil, cache live items instead."
  (message "Caching Guix store items...")
  (let (cache paths)
    (with-temp-buffer
      (call-process "guix" nil t nil "gc" (if live "--list-live" "--list-dead"))
      (goto-char (point-min))
      ;; Skip status lines.
      (forward-line 2)
      (while (not (eobp))
        (push (buffer-substring-no-properties (line-beginning-position)
                                              (line-end-position))
              paths)
        (forward-line)))
    (dolist (path paths cache)
      (with-temp-buffer
        (call-process "du" nil t nil "-sb" path)
        (goto-char (point-min))
        (push (make-guix-store-item :path path
                                    :status (if live 'live 'dead)
                                    :size (number-at-point))
              cache)))))

(defun guix-store-list-sort-items (a b)
  (let ((pretty-a (guix-store-prettify-path (aref (cadr a) 2)))
        (pretty-b (guix-store-prettify-path (aref (cadr b) 2))))
    (string< pretty-a pretty-b)))

(defun guix-store-get-entries ()
  (unless guix-store-cache
    (setq guix-store-cache (guix-store-build-cache)))
  (mapcar 'guix-store-item->entry guix-store-cache))

(bui-define-interface guix-store list
  :buffer-name "*guix store*"
  :get-entries-function 'guix-store-get-entries
  :format '((status nil 4 t)
            (size nil 10 bui-list-sort-numerically-1 :right-align t)
            (path nil 80 guix-store-list-sort-items))
  :sort-key '(size))

(let ((map guix-store-list-mode-map))
  (define-key map (kbd "k") 'guix-store-kill-items))

;;;###autoload
(defun guix-store ()
  "Display a list of store items."
  (interactive)
  (bui-get-display-entries 'guix-store 'list))

(provide 'patch-guix)