;;; org-gtd-archive-roam-daily.el --- Archive Org headings to Org-roam dailies
;;; Commentary:
;; This file provides an Elisp function to archive an Org-mode heading
;; at point to an Org-roam daily file based on its :CREATED: property.
;;; Code:

(require 'org-roam-dailies)
(require 'org-element)
(require 'org-time)

(defun amero-get-org-heading-created-property ()
  "Extract the :CREATED: property from the current Org heading.
  Returns a time string or nil if not found."
  (interactive)
  (save-excursion
    (org-back-to-heading t)
    (org-entry-get (point) "CREATED")))

(defun amero-parse-created-timestamp (timestamp-string)
  "Parse an Org-mode timestamp string like '[2026-03-16 Mon 14:05]'
  into an Emacs internal time object.
  Returns nil if parsing fails."
  (ignore-errors
    (org-time-string-to-time timestamp-string)))

(defun amero-get-daily-note-file (time-object)
  "Get the Org-roam daily note file for a given Emacs TIME-OBJECT.
  Creates the file if it doesn't exist. Returns the file path."
  (let* ((date-string (format-time-string org-roam-dailies-capture-templates-date-format time-object))
         (file-path (expand-file-name (concat date-string ".org")
                                      (expand-file-name org-roam-dailies-directory org-roam-directory))))
    ;; Ensure the directory exists
    (unless (file-exists-p (file-name-directory file-path))
      (make-directory (file-name-directory file-path) t))
    ;; Create file if it doesn't exist (org-roam-dailies-goto-date handles this,
    ;; but we need to ensure it's created and accessible for append)
    (unless (file-exists-p file-path)
      (with-temp-buffer
        (insert (format "#+title: %s\n" date-string))
        (write-file file-path)))
    file-path))

(defun org-gtd-archive-roam-daily ()
  "Archive the current Org heading to an Org-roam daily file
  based on its :CREATED: property.
  Signals an error if :CREATED: property is missing."
  (interactive)
  (unless (org-before-first-heading-p (point))
    (user-error "Point is not on an Org heading or within an Org file."))

  (let* ((created-timestamp-string (amero-get-org-heading-created-property))
         (created-time-object (and created-timestamp-string
                                   (amero-parse-created-timestamp created-timestamp-string)))
         (heading-start (save-excursion (org-back-to-heading t) (point)))
         (heading-end (save-excursion (org-end-of-subtree t) (point)))
         (heading-content (buffer-substring-no-properties heading-start heading-end))
         daily-file-path)

    (unless created-time-object
      (user-error "No date error: Heading is missing a valid :CREATED: property."))

    (setq daily-file-path (amero-get-daily-note-file created-time-object))

    (with-current-buffer (find-file-noselect daily-file-path)
      (goto-char (point-max))
      (insert "\n\n" heading-content)
      (save-buffer))

    ;; Remove the original heading
    (delete-region heading-start heading-end)
    (message "Archived heading to %s" daily-file-path)))

(provide 'org-gtd-archive-roam-daily)
;;; org-gtd-archive-roam-daily.el ends here