From 7b76d8733718ff764974656487230e4e05acb777 Mon Sep 17 00:00:00 2001
From: Simon Michael <simon@joyful.com>
Date: Mon, 22 Apr 2024 10:03:53 -1000
Subject: [PATCH] ;tools: helper for managing issue links in markdown.

---
 tools/md-issue-refs.el | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 tools/md-issue-refs.el

diff --git a/tools/md-issue-refs.el b/tools/md-issue-refs.el
new file mode 100644
index 000000000..3e0d2f80f
--- /dev/null
+++ b/tools/md-issue-refs.el
@@ -0,0 +1,42 @@
+;; Helper for managing issue links in markdown.
+;; See also markdown-mode's interactive C-c C-c c and C-c C-c u.
+
+(defun md-issue-refs (beginning end)
+  "Scan the selected region for markdown shortcut reference links
+   of the form [#NUM] and add/update link reference definitions
+   at the end, pointing to the corresponding github issues.
+   Removes any pre-existing #NUM link reference definitions from the region.
+   This is useful eg for maintaining link reference definitions in release notes.
+   XXX Currently hardcoded for the simonmichael/hledger repo.
+   XXX Does not work if parts of region are collapsed as with TAB in markdown-mode.
+   "
+  (interactive "r")
+  (setq beginning (min beginning end))
+  (setq end (max beginning end))
+  (let ((nums '()))
+    (save-excursion
+      (save-restriction
+        (widen)      ;; XXX trying to make it work with collapsed regions
+        (narrow-to-region beginning end)
+
+        ;; Remove pre-existing numeric link reference definitions
+        (goto-char (point-min))
+        (while (re-search-forward "^\\[#[0-9]+\\]:" nil t) (kill-whole-line))
+
+        ;; Scan the region and collect link IDs
+        (goto-char (point-min))
+        (while (and (< (point) (point-max))
+                    (search-forward-regexp "\\[#\\([0-9]+\\)\\]" nil t))
+          (setq nums (cons (match-string 1) nums)))
+        (setq nums (sort nums #'string-version-lessp))
+        (setq max-length (apply #'max (cons 0 (mapcar #'length nums))))
+
+        ;; Generate link reference definitions, with urls aligned
+        (goto-char (point-max))
+        (let ((fmt (concat "%-" (number-to-string (+ 4 max-length)) "s https://github.com/simonmichael/hledger/issues/%s\n")))
+          (dolist (num nums)
+            (insert
+             (format fmt (format "[#%s]:" num) num))))
+      )
+    )
+  ))