feat: add magit-style ux for ghpr-prs

ghpr-prs.el

@@ -0,0 +1,181 @@
+;;; ghpr-prs.el --- PR list buffer functionality -*- lexical-binding: t -*-
+
+;; This file is not part of GNU Emacs
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+
+;;; Commentary:
+
+;; ghpr-prs.el provides buffer-based PR list functionality using magit-section
+;; for interactive navigation and selection of pull requests.
+
+;;; Code:
+
+(require 'magit)
+(require 'magit-section)
+(require 'ghpr-api)
+(require 'ghpr-utils)
+(require 'ghpr-repo)
+
+(defvar-keymap ghpr-pr-section-map
+  :doc "Keymap for PR sections."
+  :parent magit-section-mode-map
+  "RET" #'ghpr-show-pr
+  "<remap> <magit-visit-thing>" #'ghpr-show-pr)
+
+(defvar ghpr-prs-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map "q" 'quit-window)
+    (define-key map "g" 'ghpr-prs-refresh)
+    (define-key map (kbd "RET") 'ghpr-show-pr)
+    map)
+  "Keymap for `ghpr-prs-mode'.")
+
+(define-derived-mode ghpr-prs-mode magit-mode "GHPR PRs"
+  "Major mode for listing GitHub pull requests."
+  :group 'ghpr
+  :keymap ghpr-prs-mode-map
+  (hack-dir-local-variables-non-file-buffer)
+  (setq truncate-lines t))
+
+(defvar-local ghpr--prs-repo-name nil
+  "Repository name for the current PR list buffer.")
+
+(defun ghpr--prs-setup-buffer (repo-name)
+  "Create and setup the PR list buffer for REPO-NAME, or reuse existing buffer."
+  (let* ((buffer-name (format "*ghpr-prs: %s*" repo-name))
+         (existing-buffer (get-buffer buffer-name))
+         (buffer (or existing-buffer (get-buffer-create buffer-name))))
+    (with-current-buffer buffer
+      (unless existing-buffer
+        (ghpr-prs-mode)
+        (setq ghpr--prs-repo-name repo-name))
+      (ghpr--prs-refresh-buffer))
+    buffer))
+
+(defun ghpr--prs-refresh-buffer (&optional error-message)
+  "Refresh the PR list buffer content, preserving cursor position."
+  (unless ghpr--prs-repo-name
+    (error "No repository name set in buffer"))
+  (let ((current-section (ghpr--get-current-pr))
+        (prs+error (ghpr--fetch-prs-with-error-handling error-message)))
+    (ghpr--rebuild-buffer-content (car prs+error) (cdr prs+error))
+    (ghpr--restore-cursor-or-top current-section)))
+
+(defun ghpr--get-current-pr ()
+  "Get the current PR value to restore cursor position after refresh."
+  (and (magit-current-section)
+       (oref (magit-current-section) value)))
+
+(defun ghpr--fetch-prs-with-error-handling (error-message)
+  "Fetch PRs, returning (prs . error-message) cons cell."
+  (if error-message
+      (cons nil error-message)
+    (condition-case err
+        (cons (ghpr--list-open-prs ghpr--prs-repo-name) nil)
+      (error (cons nil (error-message-string err))))))
+
+(defun ghpr--rebuild-buffer-content (prs error-message)
+  "Rebuild buffer content with PRS and optional ERROR-MESSAGE."
+  (let ((inhibit-read-only t))
+    (erase-buffer)
+    (ghpr--insert-error-if-present error-message)
+    (ghpr--insert-prs-section prs error-message)))
+
+(defun ghpr--insert-error-if-present (error-message)
+  "Insert error message at top of buffer if ERROR-MESSAGE is non-nil."
+  (when error-message
+    (insert (propertize (format "Error: %s\n\n" error-message)
+                        'face 'error))))
+
+(defun ghpr--insert-prs-section (prs error-message)
+  "Insert the main PRs section with PRS list or appropriate message."
+  (magit-insert-section (prs-buffer)
+    (magit-insert-heading (format "Pull Requests for %s" ghpr--prs-repo-name))
+    (cond
+     ((and prs (not error-message))
+      (dolist (pr prs)
+        (ghpr--insert-pr-section pr)))
+     (error-message
+      (insert "Could not fetch pull requests due to error above.\n"))
+     (t
+      (insert "No open pull requests found.\n")))))
+
+(defun ghpr--restore-cursor-or-top (current-section)
+  "Restore cursor to CURRENT-SECTION if it exists, otherwise go to top."
+  (if current-section
+      (ghpr--restore-cursor-position current-section)
+    (goto-char (point-min))))
+
+(defun ghpr--restore-cursor-position (target-pr)
+  "Restore cursor position to TARGET-PR if it still exists after refresh."
+  (goto-char (point-min))
+  (unless (ghpr--find-and-goto-pr target-pr)
+    (goto-char (point-min))))
+
+(defun ghpr--find-and-goto-pr (target-pr)
+  "Find TARGET-PR in buffer and move cursor to it. Return t if found."
+  (catch 'found
+    (while (not (eobp))
+      (when (ghpr--current-line-matches-pr-p target-pr)
+        (throw 'found t))
+      (forward-line 1))
+    nil))
+
+(defun ghpr--current-line-matches-pr-p (target-pr)
+  "Return t if current line contains a section matching TARGET-PR."
+  (let ((section (magit-current-section)))
+    (and section
+         (eq (oref section type) 'pr)
+         (equal (oref section value) target-pr))))
+
+(defun ghpr-prs-refresh ()
+  "Refresh the current PR list buffer."
+  (interactive)
+  (ghpr--prs-refresh-buffer))
+
+(defun ghpr--insert-pr-section (pr)
+  "Insert a magit section for PR."
+  (let ((pr-summary (ghpr--pr-summary pr))
+        (pr-number (alist-get 'number pr)))
+    (magit-insert-section (pr pr)
+      (oset (magit-current-section) keymap ghpr-pr-section-map)
+      (insert pr-summary)
+      (insert "\n"))))
+
+(defun ghpr-show-pr ()
+  "Open the PR at point in review mode."
+  (interactive)
+  (let* ((section (magit-current-section))
+         (pr (and section
+                  (eq (oref section type) 'pr)
+                  (oref section value)))
+         (prs-buffer (current-buffer)))
+    (if pr
+        (progn
+          (require 'ghpr-review)
+          (ghpr--open-pr pr ghpr--prs-repo-name prs-buffer))
+      (user-error "No PR at point: section-type=%S, section-value=%S"
+                  (and section (oref section type))
+                  (and section (oref section value))))))
+
+(defun ghpr-prs-list (repo-name)
+  "Display a buffer listing open PRs for REPO-NAME."
+  (let ((buffer (ghpr--prs-setup-buffer repo-name)))
+    (switch-to-buffer buffer)))
+
+(provide 'ghpr-prs)
+
+;;; ghpr-prs.el ends here