;;
;; Implement the rest of the vc interface.  See the comment at the
;; beginning of vc.el.  The current status is:
;; ("??" means: "figure out what to do about it")

;; FUNCTION NAME                                   STATUS
;; BACKEND PROPERTIES
;; * revision-granularity                          OK
;; - update-on-retrieve-tag                        OK
;; STATE-QUERYING FUNCTIONS
;; * registered (file)                             OK
;; * state (file)                                  OK
;; - dir-status-files (dir files uf)               OK
;; * working-revision (file)                       OK
;; * checkout-model (files)                        OK
;; - mode-line-string (file)                       OK
;; STATE-CHANGING FUNCTIONS
;; * create-repo ()                                OK
;; * register (files &optional _rev _comment)      OK
;; - responsible-p (file)                          OK
;; - receive-file (file rev)                       NOT NEEDED
;; - unregister (file)                             ??
;; * checkin (files comment &optional _rev)        OK
;; - checkin-patch (patch-string comment)          ??
;; * find-revision (file rev buffer)               ??
;; * checkout (file &optional rev)                 ??
;; * revert (file &optional contents-done)         OK
;; - merge-file (file rev1 rev2)                   ??
;; - merge-news (file)                             ??
;; - mark-resolved (files)                         ??
;; - steal-lock (file &optional revision)          ??
;; - clone (remote directory rev)                  OK
;; HISTORY FUNCTIONS
;; * print-log (files buffer &optional _shortlog _start-revision limit)   OK
;; * log-outgoing (buffer remote-location)         ??
;; * log-incoming (buffer remote-location)         ??
;; - log-search (buffer pattern)                   ??
;; - log-view-mode ()                              OK
;; - show-log-entry (revision)                     OK
;; - comment-history (file)                        ??
;; - update-changelog (files)                      ??
;; * diff (file &optional _rev1 rev2 buffer _async) OK
;; - revision-completion-table (files)             ??
;; - annotate-command (file buf &optional rev)     OK
;; - annotate-time ()                              OK
;; - annotate-current-time ()                      NOT NEEDED
;; - annotate-extract-revision-at-line ()          OK
;; TAG/BRANCH SYSTEM
;; - create-tag (dir name branchp)                 OK
;; - retrieve-tag (dir name update)                OK
;; MISCELLANEOUS
;; - make-version-backups-p (file)                 ??
;; - previous-revision (file-or-list rev)          OK
;; - next-revision (file-or-list rev)              OK
;; - file-name-changes (rev)                       ??
;; - check-headers ()                              ??
;; - delete-file (file)                            OK
;; - rename-file (old new)                         OK
;; - find-file-hook ()                             ??
;; - conflicted-files                              ??
;; - repository-url (file-or-dir)                  ??
;; - prepare-patch (rev)                           ??

  "Run `pijul COMMAND ARGS...' and return standard output as a string.

  "Run `pijul COMMAND ARGS...', read the JSON object and return it.

(defun vc-pijul-clone (remote directory rev)
  "Attempt to clone REMOTE repository into DIRECTORY at revision REV."
  (if (null rev)
      (vc-pijul--out-ok "clone" remote directory)
    (vc-pijul--out-ok "clone" "--state" rev remote directory))
  directory)
(defvar vc-pijul-remotes-history)
(defun vc-pijul-Clone (remote directory &optional state)
  "Attempt to clone REMOTE repository into DIRECTORY at STATE."
  (interactive
   (list (read-string "Remote: " nil 'vc-pijul-remotes-history)
         (expand-file-name
          (read-directory-name "Directory to clone: "))
         "P"))
  (let ((state (when state (read-string "State: "))))
    (find-file (vc-clone remote 'Pijul directory state))))