;;; Copyright (C) 2006 Magnus Henoch
;;;
;;; 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 2 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, write to the Free Software
;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

(in-package :darcs)

(defun pull (ourrepo &optional theirrepo)
  "Pull new patches from THEIRREPO into OURREPO.
If THEIRREPO is not specified, use default repositiory specified
in preferences."
  (setf ourrepo (fad:pathname-as-directory ourrepo))
  (unless theirrepo
    (setf theirrepo (car (get-preflist ourrepo "defaultrepo")))
    (unless theirrepo
      (error "No remote repositiory specified, and no default available.")))
  (let ((our-patchinfo (read-repo-patch-list ourrepo))
	(their-patchinfo (read-repo-patch-list theirrepo)))
    (multiple-value-bind (common only-ours only-theirs)
	(get-common-and-uncommon our-patchinfo their-patchinfo)
      (declare (ignore common))
      (format t "~&Found these new patches:")
      (dolist (p only-theirs)
	(format t "~& - ~A" p))
      ;; XXX: This is where we pick which of their patches we want to
      ;; pull.
      (let* ((their-patches
	      (mapcar (lambda (pi)
			(read-patch-from-repo theirrepo pi))
		      only-theirs))
	     (our-patches
	      (mapcar (lambda (pi)
			(read-patch-from-repo ourrepo pi))
		      only-ours))
	     (merged-patches (patches
			      (merge-patches (make-instance 'composite-patch
							    :patches their-patches)
					     (make-instance 'composite-patch
							    :patches our-patches)))))
	(format t "~&Applying patches")
	(let ((applying-to-source t)
	      (source-and-pristine-differ nil))
	  (dolist (p merged-patches)
	    ;; First, copy the modified patch to the repository.
	    (write-patch-to-repo p ourrepo)
	    ;; Then, apply it to the pristine copy.  This couldn't
	    ;; possibly fail.
	    (apply-patch-to-pristine p ourrepo)
	    ;; Note the patch in the inventory.
	    (append-inventory ourrepo (named-patch-patchinfo p))
	    ;; And finally apply the patch to the real source.  This
	    ;; could fail if the source has been modified.  Deal with
	    ;; that in a crude way.  XXX: it is wasteful to apply
	    ;; patches twice.
	    (when applying-to-source
	      (restart-case
		  (apply-patch p ourrepo)
		(skip-this ()
		    :report "Don't apply this patch to the source tree (it was applied to the pristine tree)"
		    (setf source-and-pristine-differ t))
		(skip-all ()
		    :report "Stop trying to apply patches to the source tree (they will be applied to the pristine tree)"
		    (setf source-and-pristine-differ t)
		    (setf applying-to-source nil))))
	    (format t "."))
	  (when source-and-pristine-differ
	    (format t "~&~<Some patches could not be applied to the source tree.~
You should manually merge changes from the pristine tree in _darcs/pristine/.~:@>")))))
    (format t "~&All done")))