;;; ss-capture.el --- Capture configuration -*- lexical-binding: t; -*-

;;; Commentary:

;; Journal capture helpers and capture templates.

;;; Code:

(require 'calendar)
(require 'org)
(require 'org-capture)
(require 'ss-core)
(require 'ss-org)

(defun ss-journal-capture-time ()
  "Return the effective timestamp for the current journal capture."
  (or org-overriding-default-time
      (org-capture-get :default-time)
      (current-time)))

(defun ss-journal-calendar-date (&optional time)
  "Return TIME as a Gregorian date list for datetree helpers."
  (calendar-gregorian-from-absolute
   (time-to-days (or time (current-time)))))

(defun ss-journal-year-heading (&optional time)
  "Return the journal year heading text for TIME."
  (format-time-string "%Y" (or time (current-time))))

(defun ss-journal-day-heading (&optional time)
  "Return the journal day heading text for TIME."
  (format-time-string "%Y-%m-%d %A" (or time (current-time))))

(defun ss-journal-find-or-create-heading (level heading)
  "Move to HEADING at LEVEL, creating it when missing."
  (goto-char (point-min))
  (if (re-search-forward
       (format "^%s %s$"
               (make-string level ?*)
               (regexp-quote heading))
       nil t)
      (goto-char (match-beginning 0))
    (goto-char (point-max))
    (unless (bolp)
      (insert "\n"))
    (insert (make-string level ?*) " " heading "\n")
    (forward-line -1))
  (org-back-to-heading t))

(defun ss-journal-goto-date (&optional time create)
  "Move to TIME's journal date heading.
When CREATE is non-nil, create the datetree entry when missing."
  (goto-char (point-min))
  (if create
      (let ((year-heading (ss-journal-year-heading time))
            (day-heading (ss-journal-day-heading time)))
        (ss-journal-find-or-create-heading 1 year-heading)
        (save-restriction
          (org-narrow-to-subtree)
          (ss-journal-find-or-create-heading 2 day-heading))
        t)
    (when (re-search-forward
           (format "^\\*\\* %s$"
                   (regexp-quote
                    (ss-journal-day-heading (or time (current-time)))))
           nil t)
      (goto-char (match-beginning 0))
      t)))

(defun ss-journal-ensure-day-sections ()
  "Ensure the standard section headings exist under the current journal day."
  (org-back-to-heading t)
  (let ((section-level (1+ (org-outline-level))))
    (save-excursion
      (save-restriction
        (org-narrow-to-subtree)
        (dolist (section ss-journal-section-headings)
          (goto-char (point-min))
          (unless (org-find-exact-headline-in-buffer section)
            (goto-char (point-max))
            (unless (bolp)
              (insert "\n"))
            (insert (make-string section-level ?*) " " section "\n")))))))

(defun ss-journal-goto-section (section &optional time)
  "Move to SECTION beneath TIME's journal date, creating structure as needed."
  (unless (member section ss-journal-section-headings)
    (user-error "Unknown journal section: %s" section))
  (ss-journal-goto-date time 'create)
  (ss-journal-ensure-day-sections)
  (let ((section-level (1+ (org-outline-level)))
        position)
    (save-restriction
      (org-narrow-to-subtree)
      (goto-char (point-min))
      (when (re-search-forward
             (format "^%s %s$"
                     (make-string section-level ?*)
                     (regexp-quote section))
             nil t)
        (setq position (match-beginning 0))))
    (unless position
      (user-error "Journal section not found: %s" section))
    (goto-char position)
    (org-back-to-heading t)))

(defun ss-journal-capture-target (section)
  "Select SECTION under today's journal datetree entry for capture."
  (set-buffer (find-file-noselect (ss-require-existing-file ss-journal-file)))
  (widen)
  (ss-journal-goto-section section (ss-journal-capture-time)))

(defun ss-capture--denote-templates ()
  "Return Denote-backed capture templates when Denote is enabled."
  (when (ss-feature-enabled-p 'denote)
    `(("n" "Denote")
      ("nn" "Generic" plain
       (file denote-last-path)
       (function
        (lambda ()
          (denote-org-capture-with-prompts :title :keywords :subdirectory)))
       :no-save t
       :immediate-finish nil
       :kill-buffer t
       :jump-to-captured t)
      ("np" "Project" plain
       (file denote-last-path)
       (function
        (lambda ()
          (ss-denote-capture-in-directory
           ss-org-projects-directory '("project") :title :keywords :subdirectory)))
       :no-save t
       :immediate-finish nil
       :kill-buffer t
       :jump-to-captured t)
      ("na" "Area" plain
       (file denote-last-path)
       (function
        (lambda ()
          (ss-denote-capture-in-directory
           ss-org-areas-directory nil :title :keywords :subdirectory)))
       :no-save t
       :immediate-finish nil
       :kill-buffer t
       :jump-to-captured t)
      ("nr" "Resource" plain
       (file denote-last-path)
       (function
        (lambda ()
          (ss-denote-capture-in-directory
           ss-org-resources-directory nil :title :keywords :subdirectory)))
       :no-save t
       :immediate-finish nil
       :kill-buffer t
       :jump-to-captured t))))

(defun ss-capture-setup ()
  "Initialize capture templates."
  (setq org-capture-templates
        (append
         '(("j" "Journal")
           ("jt" "Task" entry
            (function (lambda () (ss-journal-capture-target "Tasks")))
            "* TODO %?")
           ("jn" "Note" entry
            (function (lambda () (ss-journal-capture-target "Notes")))
            "* %?")
           ("jm" "Meeting" entry
            (function (lambda () (ss-journal-capture-target "Meetings")))
            "* <%<%Y-%m-%d %H:%M>> %?"))
         (ss-capture--denote-templates))))

(provide 'ss-capture)

;;; ss-capture.el ends here