;;; vc-mtn.el --- VC backend for Monotone  -*- lexical-binding: t -*-

;; Copyright (C) 2007-2022 Free Software Foundation, Inc.

;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
;; Keywords: vc
;; Package: vc

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;;

;;; TODO:

;; - The `previous-version' VC method needs to be supported, 'D' in
;;   log-view-mode uses it.

;;; Code:

(eval-when-compile (require 'vc))

(defgroup vc-mtn nil
  "VC Monotone (mtn) backend."
  :version "24.1"
  :group 'vc)

(defcustom vc-mtn-diff-switches t
  "String or list of strings specifying switches for monotone diff under VC.
If nil, use the value of `vc-diff-switches'.  If t, use no switches."
  :type '(choice (const :tag "Unspecified" nil)
		 (const :tag "None" t)
		 (string :tag "Argument String")
		 (repeat :tag "Argument List" :value ("") string))
  :version "23.1")

(defcustom vc-mtn-annotate-switches nil
  "String or list of strings specifying switches for mtn annotate under VC.
If nil, use the value of `vc-annotate-switches'.  If t, use no
switches."
  :type '(choice (const :tag "Unspecified" nil)
		 (const :tag "None" t)
		 (string :tag "Argument String")
		 (repeat :tag "Argument List" :value ("") string))
  :version "25.1")

(defcustom vc-mtn-program "mtn"
  "Name of the monotone executable."
  :type 'string)

;; Clear up the cache to force vc-call to check again and discover
;; new functions when we reload this file.
(put 'Mtn 'vc-functions nil)

(unless (executable-find vc-mtn-program)
  ;; vc-mtn.el is 100% non-functional without the `mtn' executable.
  (setq vc-handled-backends (delq 'Mtn vc-handled-backends)))

;;;###autoload
(defconst vc-mtn-admin-dir "_MTN" "Name of the monotone directory.")
;;;###autoload
(defconst vc-mtn-admin-format (concat vc-mtn-admin-dir "/format")
  "Name of the monotone directory's format file.")

;;;###autoload (defun vc-mtn-registered (file)
;;;###autoload   (if (vc-find-root file vc-mtn-admin-format)
;;;###autoload       (progn
;;;###autoload         (load "vc-mtn" nil t)
;;;###autoload         (vc-mtn-registered file))))

(defun vc-mtn-revision-granularity () 'repository)
(defun vc-mtn-checkout-model (_files) 'implicit)

(defun vc-mtn-root (file)
  (setq file (expand-file-name file)
	file (if (file-directory-p file)
                 (file-name-as-directory file)
               (file-name-directory file)))
  (or (vc-file-getprop file 'vc-mtn-root)
      (vc-file-setprop file 'vc-mtn-root
                       (vc-find-root file vc-mtn-admin-format))))

(defun vc-mtn-find-admin-dir (file)
  "Return the administrative directory of FILE."
  (expand-file-name vc-mtn-admin-dir (vc-mtn-root file)))

(defun vc-mtn-find-ignore-file (file)
  "Return the mtn ignore file that controls FILE."
  (expand-file-name ".mtnignore" (vc-mtn-root file)))

(defun vc-mtn-registered (file)
  (let ((root (vc-mtn-root file)))
    (when root
      (vc-mtn-state file))))

(defun vc-mtn-command (buffer okstatus files &rest flags)
  "A wrapper around `vc-do-command' for use in vc-mtn.el."
  (let ((process-environment
         ;; Avoid localization of messages so we can parse the output.
         (cons "LC_MESSAGES=C" process-environment)))
    (apply #'vc-do-command (or buffer "*vc*") okstatus vc-mtn-program
           files flags)))

(defun vc-mtn-state (file)
  ;; If `mtn' fails or returns status>0, or if the search files, just
  ;; return nil.
  (ignore-errors
    (with-temp-buffer
      (vc-mtn-command t 0 file "status")
      (goto-char (point-min))
      (re-search-forward
       "^  \\(?:\\(patched\\)\\|\\(added\\) \\(?:.*\\)\\)\\|no changes$")
      (cond  ((match-end 1) 'edited)
	     ((match-end 2) 'added)
	     (t 'up-to-date)))))

(defun vc-mtn-after-dir-status (update-function)
  (let (result)
    (goto-char (point-min))
    (re-search-forward "\\(?:Current b\\|B\\)ranch:  *\\(.*\\)\n?\nChanges against parent \\(.*\\)" nil t)
    (while (re-search-forward
	    "^  \\(?:\\(patched  \\)\\|\\(added    \\)\\)\\(.*\\)$" nil t)
      (cond  ((match-end 1) (push (list (match-string 3) 'edited) result))
	     ((match-end 2) (push (list (match-string 3) 'added) result))))
    (funcall update-function result)))

;; dir-status-files called from vc-dir, which loads vc,
;; which loads vc-dispatcher.
(declare-function vc-exec-after "vc-dispatcher" (code))

(defun vc-mtn-dir-status-files (dir _files update-function)
  (vc-mtn-command (current-buffer) 'async dir "status")
  (vc-run-delayed
   (vc-mtn-after-dir-status update-function)))

(defun vc-mtn-working-revision (file)
  ;; If `mtn' fails or returns status>0, or if the search fails, just
  ;; return nil.
  (ignore-errors
    (with-temp-buffer
      (vc-mtn-command t 0 file "status")
      (goto-char (point-min))
      (re-search-forward "\\(?:Current b\\|B\\)ranch:  *\\(.*\\)\n?\nChanges against parent \\(.*\\)")
      (match-string 2))))

(defun vc-mtn-workfile-branch (file)
  ;; If `mtn' fails or returns status>0, or if the search files, just
  ;; return nil.
  (ignore-errors
    (with-temp-buffer
      (vc-mtn-command t 0 file "status")
      (goto-char (point-min))
      (re-search-forward "\\(?:Current b\\|B\\)ranch:  *\\(.*\\)\n?\nChanges against parent \\(.*\\)")
      (match-string 1))))

;; Mode-line rewrite code copied from vc-arch.el.

(defcustom vc-mtn-mode-line-rewrite
  '(("\\`[^:/#]*[:/#]" . ""))           ;Drop the host part.
  "Rewrite rules to shorten Mtn's revision names on the mode-line."
  :type '(repeat (cons regexp string))
  :version "22.2")

(defun vc-mtn-mode-line-string (file)
  "Return a string for `vc-mode-line' to put in the mode line for FILE."
  (let ((branch (vc-mtn-workfile-branch file)))
    (if branch
        (progn
          (dolist (rule vc-mtn-mode-line-rewrite)
            (if (string-match (car rule) branch)
                (setq branch (replace-match (cdr rule) t nil branch))))
          (format "Mtn%c%s"
                  (pcase (vc-state file)
                    ((or 'up-to-date 'needs-update) ?-)
                    ('added ?@)
                    (_ ?:))
                  branch))
      "")))

(defun vc-mtn-register (files &optional _comment)
  (vc-mtn-command nil 0 files "add"))

(defun vc-mtn-responsible-p (file) (vc-mtn-root file))

(declare-function log-edit-extract-headers "log-edit" (headers string))

(defun vc-mtn-checkin (files comment &optional _rev)
  (apply #'vc-mtn-command nil 0 files
	 (nconc (list "commit" "-m")
		(log-edit-extract-headers '(("Author" . "--author")
					    ("Date" . "--date"))
					  comment))))

(defun vc-mtn-find-revision (file rev buffer)
  ;; null rev means latest revision
  (if rev
      (vc-mtn-command buffer 0 file "cat" "-r" rev)
    (vc-mtn-command buffer 0 file "cat")))

;; (defun vc-mtn-checkout (file &optional rev)
;;   )

(defun vc-mtn-revert (file &optional contents-done)
  (unless contents-done
    (vc-mtn-command nil 0 file "revert")))

(defun vc-mtn-print-log (files buffer &optional _shortlog start-revision limit)
  "Print commit logs associated with FILES into specified BUFFER.
_SHORTLOG is ignored.
If START-REVISION is non-nil, it is the newest revision to show.
If LIMIT is non-nil, show no more than this many entries."
  (apply #'vc-mtn-command buffer 0 files "log"
	 (append
	  (when start-revision (list "--from" (format "%s" start-revision)))
	  (when limit (list "--last" (format "%s" limit))))))

(defvar log-view-message-re)
(defvar log-view-file-re)
(defvar log-view-font-lock-keywords)
(defvar log-view-per-file-logs)

(define-derived-mode vc-mtn-log-view-mode log-view-mode "Mtn-Log-View"
  ;; Don't match anything.
  (setq-local log-view-file-re regexp-unmatchable)
  (setq-local log-view-per-file-logs nil)
  ;; TODO: Use a more precise regexp than "[ |/]+" to avoid false positives
  ;; in the ChangeLog text.
  (setq-local log-view-message-re
              "^[ |/]+Revision: \\([0-9a-f]+\\)")
  (require 'add-log)                    ;For change-log faces.
  (setq-local log-view-font-lock-keywords
       (append log-view-font-lock-keywords
               '(("^[ |]+Author: \\(.*\\)" (1 'change-log-email))
                 ("^[ |]+Date: \\(.*\\)" (1 'change-log-date))))))

;; (defun vc-mtn-show-log-entry (revision)
;;   )

(autoload 'vc-switches "vc")

(defun vc-mtn-diff (files &optional rev1 rev2 buffer _async)
  "Get a difference report using monotone between two revisions of FILES."
  (apply #'vc-mtn-command (or buffer "*vc-diff*")
	 1 ; bug#21969
	 files "diff"
         (append
           (vc-switches 'mtn 'diff)
           (if rev1 (list "-r" rev1)) (if rev2 (list "-r" rev2)))))

(defun vc-mtn-annotate-command (file buf &optional rev)
  (apply #'vc-mtn-command buf 'async file "annotate"
	 (append (vc-switches 'mtn 'annotate)
		 (if rev (list "-r" rev)))))

(declare-function vc-annotate-convert-time "vc-annotate" (&optional time))

(defconst vc-mtn-annotate-full-re
  "^ *\\([0-9a-f]+\\)\\.* by [^ ]+ \\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\): ")
(defconst vc-mtn-annotate-any-re
  (concat "^\\(?: +: \\|" vc-mtn-annotate-full-re "\\)"))

(defun vc-mtn-annotate-time ()
  (when (looking-at vc-mtn-annotate-any-re)
    (goto-char (match-end 0))
    (let ((year (match-string 2)))
      (if (not year)
          ;; Look for the date on a previous line.
          (save-excursion
            (get-text-property (1- (previous-single-property-change
                                    (point) 'vc-mtn-time nil (point-min)))
                               'vc-mtn-time))
        (let ((time (vc-annotate-convert-time
                     (encode-time 0 0 0
                                  (string-to-number (match-string 4))
                                  (string-to-number (match-string 3))
                                  (string-to-number year)
                                  t))))
          (let ((inhibit-read-only t)
                (inhibit-modification-hooks t))
            (put-text-property (match-beginning 0) (match-end 0)
                               'vc-mtn-time time))
          time)))))

(defun vc-mtn-annotate-extract-revision-at-line ()
  (save-excursion
    (when (or (looking-at vc-mtn-annotate-full-re)
              (re-search-backward vc-mtn-annotate-full-re nil t))
      (match-string 1))))

;;; Revision completion.

(defun vc-mtn-list-tags ()
  (with-temp-buffer
    (vc-mtn-command t 0 nil "list" "tags")
    (goto-char (point-min))
    (let ((tags ()))
      (while (re-search-forward "^[^ ]+" nil t)
        (push (match-string 0) tags))
      tags)))

(defun vc-mtn-list-branches ()
  (with-temp-buffer
    (vc-mtn-command t 0 nil "list" "branches")
    (goto-char (point-min))
    (let ((branches ()))
      (while (re-search-forward "^.+" nil t)
        (push (match-string 0) branches))
      branches)))

(defun vc-mtn-list-revision-ids (prefix)
  (with-temp-buffer
    (vc-mtn-command t 0 nil "complete" "revision" prefix)
    (goto-char (point-min))
    (let ((ids ()))
      (while (re-search-forward "^.+" nil t)
        (push (match-string 0) ids))
      ids)))

(defun vc-mtn-revision-completion-table (_files)
  ;; What about using `files'?!?  --Stef
  (lambda (string pred action)
    (cond
     ;; Special chars for composite selectors.
     ((string-match ".*[^\\]\\(\\\\\\\\\\)*[/|;(]" string)
      (completion-table-with-context (substring string 0 (match-end 0))
                                     (vc-mtn-revision-completion-table nil)
                                     (substring string (match-end 0))
                                     pred action))
     ;; "Tag" selectors.
     ((string-match "\\`t:" string)
      (complete-with-action action
                            (mapcar (lambda (tag) (concat "t:" tag))
                                    (vc-mtn-list-tags))
                            string pred))
     ;; "Branch" or "Head" selectors.
     ((string-match "\\`[hb]:" string)
      (let ((prefix (match-string 0 string)))
        (complete-with-action action
                              (mapcar (lambda (tag) (concat prefix tag))
                                      (vc-mtn-list-branches))
                              string pred)))
     ;; "ID" selectors.
     ((string-match "\\`i:" string)
      (complete-with-action action
                            (mapcar (lambda (tag) (concat "i:" tag))
                                    (vc-mtn-list-revision-ids
                                     (substring string (match-end 0))))
                            string pred))
     (t
      (complete-with-action action
                            '("t:" "b:" "h:" "i:"
                              ;; Completion not implemented for these.
                              "c:" "a:" "k:" "d:" "m:" "e:" "l:" "i:" "p:"
                              ;; These have no arg to complete.
                              "u:" "w:"
                              ;; Selector functions.
                              "difference(" "lca(" "max(" "ancestors("
                              "descendants(" "parents(" "children("
                              "pick(")
                            string pred)))))



(provide 'vc-mtn)

;;; vc-mtn.el ends here
