;;; mq.el --- Emacs support for Mercurial Queues

 ;; Copyright (C) 2006 Bryan O'Sullivan

 ;; Author: Bryan O'Sullivan <bos@serpentine.com>

 ;; mq.el is free software; you can redistribute it and/or modify it

 ;; under the terms of the GNU General Public License version 2 or any

 ;; later version.

 ;; mq.el 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 mq.el, GNU Emacs, or XEmacs; see the file COPYING (`C-h

 ;; C-l').  If not, see <http://www.gnu.org/licenses/>.

 (eval-when-compile (require 'cl))

 (require 'mercurial)

 (defcustom mq-mode-hook nil

   "Hook run when a buffer enters mq-mode."

   :type 'sexp

   :group 'mercurial)

 (defcustom mq-global-prefix "\C-cq"

   "The global prefix for Mercurial Queues keymap bindings."

   :type 'sexp

   :group 'mercurial)

 (defcustom mq-edit-mode-hook nil

   "Hook run after a buffer is populated to edit a patch description."

   :type 'sexp

   :group 'mercurial)

 (defcustom mq-edit-finish-hook nil

   "Hook run before a patch description is finished up with."

   :type 'sexp

   :group 'mercurial)

 (defcustom mq-signoff-address nil

   "Address with which to sign off on a patch."

   :type 'string

   :group 'mercurial)

 ;;; Internal variables.

 (defvar mq-mode nil

   "Is this file managed by MQ?")

 (make-variable-buffer-local 'mq-mode)

 (put 'mq-mode 'permanent-local t)

 (defvar mq-patch-history nil)

 (defvar mq-top-patch '(nil))

 (defvar mq-prev-buffer nil)

 (make-variable-buffer-local 'mq-prev-buffer)

 (put 'mq-prev-buffer 'permanent-local t)

 (defvar mq-top nil)

 (make-variable-buffer-local 'mq-top)

 (put 'mq-top 'permanent-local t)

 ;;; Global keymap.

 (defvar mq-global-map

   (let ((map (make-sparse-keymap)))

     (define-key map "." 'mq-push)

     (define-key map ">" 'mq-push-all)

     (define-key map "," 'mq-pop)

     (define-key map "<" 'mq-pop-all)

     (define-key map "=" 'mq-diff)

     (define-key map "r" 'mq-refresh)

     (define-key map "e" 'mq-refresh-edit)

     (define-key map "i" 'mq-new)

     (define-key map "n" 'mq-next)

     (define-key map "o" 'mq-signoff)

     (define-key map "p" 'mq-previous)

     (define-key map "s" 'mq-edit-series)

     (define-key map "t" 'mq-top)

     map))

 (global-set-key mq-global-prefix mq-global-map)

 (add-minor-mode 'mq-mode 'mq-mode)

 ;;; Refresh edit mode keymap.

 (defvar mq-edit-mode-map

   (let ((map (make-sparse-keymap)))

     (define-key map "\C-c\C-c" 'mq-edit-finish)

     (define-key map "\C-c\C-k" 'mq-edit-kill)

     (define-key map "\C-c\C-s" 'mq-signoff)

     map))

 ;;; Helper functions.

 (defun mq-read-patch-name (&optional source prompt force)

   "Read a patch name to use with a command.

 May return nil, meaning \"use the default\"."

   (let ((patches (split-string

 		  (hg-chomp (hg-run0 (or source "qseries"))) "\n")))

     (when force

       (completing-read (format "Patch%s: " (or prompt ""))

 		       (mapcar (lambda (x) (cons x x)) patches)

 		       nil

 		       nil

 		       nil

 		       'mq-patch-history))))

 (defun mq-refresh-buffers (root)

   (save-excursion

     (dolist (buf (hg-buffers-visiting-repo root))

       (when (not (verify-visited-file-modtime buf))

 	(set-buffer buf)

 	(let ((ctx (hg-buffer-context)))

 	  (message "Refreshing %s..." (buffer-name))

 	  (revert-buffer t t t)

 	  (hg-restore-context ctx)

 	  (message "Refreshing %s...done" (buffer-name))))))

   (hg-update-mode-lines root)

   (mq-update-mode-lines root))

 (defun mq-last-line ()

   (goto-char (point-max))

   (beginning-of-line)

   (when (looking-at "^$")

     (forward-line -1))

   (let ((bol (point)))

     (end-of-line)

     (let ((line (buffer-substring bol (point))))

       (when (> (length line) 0)

 	line))))

 (defun mq-push (&optional patch)

   "Push patches until PATCH is reached.

 If PATCH is nil, push at most one patch."

   (interactive (list (mq-read-patch-name "qunapplied" " to push"

 					 current-prefix-arg)))

   (let ((root (hg-root))

 	(prev-buf (current-buffer))

 	last-line ok)

     (unless root

       (error "Cannot push outside a repository!"))

     (hg-sync-buffers root)

     (let ((buf-name (format "MQ: Push %s" (or patch "next patch"))))

       (kill-buffer (get-buffer-create buf-name))

       (split-window-vertically)

       (other-window 1)

       (switch-to-buffer (get-buffer-create buf-name))

       (cd root)

       (message "Pushing...")

       (setq ok (= 0 (apply 'call-process (hg-binary) nil t t "qpush"

 			   (if patch (list patch))))

 	    last-line (mq-last-line))

       (let ((lines (count-lines (point-min) (point-max))))

 	(if (or (<= lines 1)

 		(and (equal lines 2) (string-match "Now at:" last-line)))

 	    (progn

 	      (kill-buffer (current-buffer))

 	      (delete-window))

 	  (hg-view-mode prev-buf))))

     (mq-refresh-buffers root)

     (sit-for 0)

     (when last-line

       (if ok

 	  (message "Pushing... %s" last-line)

 	(error "Pushing... %s" last-line)))))

 (defun mq-push-all ()

   "Push patches until all are applied."

   (interactive)

   (mq-push "-a"))

 (defun mq-pop (&optional patch)

   "Pop patches until PATCH is reached.

 If PATCH is nil, pop at most one patch."

   (interactive (list (mq-read-patch-name "qapplied" " to pop to"

 					 current-prefix-arg)))

   (let ((root (hg-root))

 	last-line ok)

     (unless root

       (error "Cannot pop outside a repository!"))

     (hg-sync-buffers root)

     (set-buffer (generate-new-buffer "qpop"))

     (cd root)

     (message "Popping...")

     (setq ok (= 0 (apply 'call-process (hg-binary) nil t t "qpop"

 			 (if patch (list patch))))

 	  last-line (mq-last-line))

     (kill-buffer (current-buffer))

     (mq-refresh-buffers root)

     (sit-for 0)

     (when last-line

       (if ok

 	  (message "Popping... %s" last-line)

 	(error "Popping... %s" last-line)))))

 (defun mq-pop-all ()

   "Push patches until none are applied."

   (interactive)

   (mq-pop "-a"))

 (defun mq-refresh-internal (root &rest args)

   (hg-sync-buffers root)

   (let ((patch (mq-patch-info "qtop")))

     (message "Refreshing %s..." patch)

     (let ((ret (apply 'hg-run "qrefresh" args)))

       (if (equal (car ret) 0)

 	  (message "Refreshing %s... done." patch)

 	(error "Refreshing %s... %s" patch (hg-chomp (cdr ret)))))))

 (defun mq-refresh (&optional git)

   "Refresh the topmost applied patch.

 With a prefix argument, generate a git-compatible patch."

   (interactive "P")

   (let ((root (hg-root)))

     (unless root

       (error "Cannot refresh outside of a repository!"))

     (apply 'mq-refresh-internal root (if git '("--git")))))

 (defun mq-patch-info (cmd &optional msg)

   (let* ((ret (hg-run cmd))

 	 (info (hg-chomp (cdr ret))))

     (if (equal (car ret) 0)

 	(if msg

 	    (message "%s patch: %s" msg info)

 	  info)

       (error "%s" info))))

 (defun mq-top ()

   "Print the name of the topmost applied patch."

   (interactive)

   (mq-patch-info "qtop" "Top"))

 (defun mq-next ()

   "Print the name of the next patch to be pushed."

   (interactive)

   (mq-patch-info "qnext" "Next"))

 (defun mq-previous ()

   "Print the name of the first patch below the topmost applied patch.

 This would become the active patch if popped to."

   (interactive)

   (mq-patch-info "qprev" "Previous"))

 (defun mq-edit-finish ()

   "Finish editing the description of this patch, and refresh the patch."

   (interactive)

   (unless (equal (mq-patch-info "qtop") mq-top)

     (error "Topmost patch has changed!"))

   (hg-sync-buffers hg-root)

   (run-hooks 'mq-edit-finish-hook)

   (mq-refresh-internal hg-root "-m" (buffer-substring (point-min) (point-max)))

   (let ((buf mq-prev-buffer))

     (kill-buffer nil)

     (switch-to-buffer buf)))

 (defun mq-edit-kill ()

   "Kill the edit currently being prepared."

   (interactive)

   (when (or (not (buffer-modified-p)) (y-or-n-p "Really kill this edit? "))

     (let ((buf mq-prev-buffer))

       (kill-buffer nil)

       (switch-to-buffer buf))))

 (defun mq-get-top (root)

   (let ((entry (assoc root mq-top-patch)))

     (if entry

         (cdr entry))))

 (defun mq-set-top (root patch)

   (let ((entry (assoc root mq-top-patch)))

     (if entry

         (if patch

             (setcdr entry patch)

           (setq mq-top-patch (delq entry mq-top-patch)))

       (setq mq-top-patch (cons (cons root patch) mq-top-patch)))))

 (defun mq-update-mode-lines (root)

   (let ((cwd default-directory))

     (cd root)

     (condition-case nil

         (mq-set-top root (mq-patch-info "qtop"))

       (error (mq-set-top root nil)))

     (cd cwd))

   (let ((patch (mq-get-top root)))

     (save-excursion

       (dolist (buf (hg-buffers-visiting-repo root))

         (set-buffer buf)

         (if mq-mode

             (setq mq-mode (or (and patch (concat " MQ:" patch)) " MQ")))))))

 (defun mq-mode (&optional arg)

   "Minor mode for Mercurial repositories with an MQ patch queue"

   (interactive "i")

   (cond ((hg-root)

          (setq mq-mode (if (null arg) (not mq-mode)

                          arg))

          (mq-update-mode-lines (hg-root))))

   (run-hooks 'mq-mode-hook))

 (defun mq-edit-mode ()

   "Mode for editing the description of a patch.

 Key bindings

 ------------

 \\[mq-edit-finish]	use this description

 \\[mq-edit-kill]	abandon this description"

   (interactive)

   (use-local-map mq-edit-mode-map)

   (set-syntax-table text-mode-syntax-table)

   (setq local-abbrev-table text-mode-abbrev-table

 	major-mode 'mq-edit-mode

 	mode-name "MQ-Edit")

   (set-buffer-modified-p nil)

   (setq buffer-undo-list nil)

   (run-hooks 'text-mode-hook 'mq-edit-mode-hook))

 (defun mq-refresh-edit ()

   "Refresh the topmost applied patch, editing the patch description."

   (interactive)

   (while mq-prev-buffer

     (set-buffer mq-prev-buffer))

   (let ((root (hg-root))

 	(prev-buffer (current-buffer))

 	(patch (mq-patch-info "qtop")))

     (hg-sync-buffers root)

     (let ((buf-name (format "*MQ: Edit description of %s*" patch)))

       (switch-to-buffer (get-buffer-create buf-name))

       (when (= (point-min) (point-max))

 	(set (make-local-variable 'hg-root) root)

 	(set (make-local-variable 'mq-top) patch)

 	(setq mq-prev-buffer prev-buffer)

 	(insert (hg-run0 "qheader"))

 	(goto-char (point-min)))

       (mq-edit-mode)

       (cd root)))

   (message "Type `C-c C-c' to finish editing and refresh the patch."))

 (defun mq-new (name)

   "Create a new empty patch named NAME.

 The patch is applied on top of the current topmost patch.

 With a prefix argument, forcibly create the patch even if the working

 directory is modified."

   (interactive (list (mq-read-patch-name "qseries" " to create" t)))

   (message "Creating patch...")

   (let ((ret (if current-prefix-arg

 		 (hg-run "qnew" "-f" name)

 	       (hg-run "qnew" name))))

     (if (equal (car ret) 0)

 	(progn

 	  (hg-update-mode-lines (buffer-file-name))

 	  (message "Creating patch... done."))

       (error "Creating patch... %s" (hg-chomp (cdr ret))))))

 (defun mq-edit-series ()

   "Edit the MQ series file directly."

   (interactive)

   (let ((root (hg-root)))

     (unless root

       (error "Not in an MQ repository!"))

     (find-file (concat root ".hg/patches/series"))))

 (defun mq-diff (&optional git)

   "Display a diff of the topmost applied patch.

 With a prefix argument, display a git-compatible diff."

   (interactive "P")

   (hg-view-output ((format "MQ: Diff of %s" (mq-patch-info "qtop")))

     (if git

 	(call-process (hg-binary) nil t nil "qdiff" "--git")

     (call-process (hg-binary) nil t nil "qdiff"))

     (diff-mode)

     (font-lock-fontify-buffer)))

 (defun mq-signoff ()

   "Sign off on the current patch, in the style used by the Linux kernel.

 If the variable mq-signoff-address is non-nil, it will be used, otherwise

 the value of the ui.username item from your hgrc will be used."

   (interactive)

   (let ((was-editing (eq major-mode 'mq-edit-mode))

 	signed)

     (unless was-editing

       (mq-refresh-edit))

     (save-excursion

       (let* ((user (or mq-signoff-address

 		       (hg-run0 "debugconfig" "ui.username")))

 	     (signoff (concat "Signed-off-by: " user)))

 	(if (search-forward signoff nil t)