(require 'org-archive)

; Set the function to use for org-archive-default  (C-c C-x C-a)
; (setq org-archive-location (concat org-directory "/archive/%s_archive::"))
; (setq org-archive-location "archive/archived_%s::")
(setq org-archive-location "::* ARCHIVED")

; unmap org-archive-subtree
(define-key org-mode-map (kbd "C-c C-x C-s") nil)

; select command to execute via org-archive-subtree-default (C-c C-x C-a)
(setq org-archive-default-command 'org-archive-subtree-hierarchical)

(defun line-content-as-string ()
  "Returns the content of the current line as a string"
  (save-excursion
    (beginning-of-line)
    (buffer-substring-no-properties
     (line-beginning-position) (line-end-position))))

(defun org-child-list (&optional top-level)
  "This function returns all children of a heading as a list. "
  (interactive)
  (save-excursion
    ;; this only works with org-version > 8.0, since in previous
    ;; org-mode versions the function (org-outline-level) returns
    ;; gargabe when the point is not on a heading.
    (unless top-level
        (if (= (org-outline-level) 0)
            (outline-next-visible-heading 1)
        (org-goto-first-child)))
    (let ((child-list (list (line-content-as-string))))
      (while (org-goto-sibling)
        (setq child-list (cons (line-content-as-string) child-list)))
      child-list)))

(defun fa/org-struct-subtree ()
  "This function returns the tree structure in which a subtree
belongs as a list."
  (interactive)
  (let ((archive-tree nil))
    (save-excursion
      (while (org-up-heading-safe)
        (let ((heading
               (buffer-substring-no-properties
                (line-beginning-position) (line-end-position))))
          (if (eq archive-tree nil)
              (setq archive-tree (list heading))
            (setq archive-tree (cons heading archive-tree))))))
    archive-tree))

(defun org-archive-subtree-hierarchical ()
  "This function archives a subtree hierarchical"
  (interactive)
  (let ((org-tree (fa/org-struct-subtree))
        (this-buffer (current-buffer))
        (file (abbreviate-file-name
                   (or (buffer-file-name (buffer-base-buffer))
                       (error "No file associated to buffer")))))
    (save-excursion
      (setq location (org-get-local-archive-location)
            afile (org-extract-archive-file location)
            heading (org-extract-archive-heading location)
            infile-p (equal file (abbreviate-file-name (or afile ""))))
      (unless afile
        (error "Invalid `org-archive-location'"))
      (if (not (equal heading ""))
          (progn
            (setq org-tree (cons heading
                               (mapcar (lambda (s) (concat "*" s)) org-tree)))
            (org-demote-subtree)))
      (if (> (length afile) 0)
          (setq newfile-p (not (file-exists-p afile))
                visiting (find-buffer-visiting afile)
                buffer (or visiting (find-file-noselect afile)))
        (progn
          (clone-indirect-buffer)
          (setq buffer (current-buffer))))
      (unless buffer
        (error "Cannot access file \"%s\"" afile))
      (org-cut-subtree)
      (set-buffer buffer)
      (org-mode)
      (goto-char (point-min))

      ; simplified version of org-complex-heading-regexp-format
      (setq my-org-complex-heading-regexp-format
        (concat "^"
          "\\(%s\\)"
          "\\(?: *\\[[0-9%%/]+\\]\\)*"
          "\\(?:[ \t]+\\(:[[:alnum:]_@#%%:]+:\\)\\)?"
          "[ \t]*$"))
      (setq top-level-p t)
      (while (not (equal org-tree nil))
        (let ((child-list (org-child-list top-level-p))
              (re (format my-org-complex-heading-regexp-format (regexp-quote (car org-tree))))
             )
          (if (member "______FOUND_MATCH" (mapcar (lambda (s) (replace-regexp-in-string re "______FOUND_MATCH" s)) child-list))
              (progn
                (re-search-forward re nil t)
                (setq org-tree (cdr org-tree)))
            (progn
              (if (not top-level-p) (newline))
              (org-insert-struct org-tree)
              (setq org-tree nil))))
        (setq top-level-p nil))
      (newline)
      (org-yank)
      ;; Save and kill the buffer, if it is not the same buffer.
      (when (not (eq this-buffer buffer))
        (save-buffer)
        (kill-buffer))
      (message "Subtree archived %s"
               (concat "in file: " (abbreviate-file-name afile))))))

(defun org-insert-struct (struct)
  "TODO"
  (interactive)
  (when struct
    (insert (car struct))
    (if  (not (equal (length struct) 1))
        (newline))
    (org-insert-struct (cdr struct))))