(require 'seq)


(setq warning-minimum-log-level :debug)
(setq warning-minimum-level :debug)

(bind-key "<f12>" 'replay-debbugs-step0)
(bind-key "<f12>" 'replay-debbugs-step1)

(defun replay-debbugs-step0 ()
  (interactive)
  (let ((case-fold-search nil)
        (default-directory (expand-file-name "~/src/debbugs")))
    (shell-command "rm -rf *")
    (shell-command "tar -x --strip=1  -f ~/Downloads/debbugs.gnu.tar")
    ;; These files are redundant, and seem to have a too new timestamp.
    (delete-file "Debbugs/Status.pm.BAK")
    (delete-file "Debbugs/MIME.pm.BAK")
    ;; This is an empty file.
    (delete-file "templates/en_US/mail/process_archived_bug.tmpl.BAK"))
  (bind-key "<f12>" 'replay-debbugs-step1))

(defvar replay-debbugs-file-versions-list nil)

(defun replay-debbugs-basename (filename)
  (if (string-match "\\(?:[.]v[0-9]+\\|[.][A-Z]+\\|[.]old\\|[.]new\\|~\\|[.]~[0-9]+~\\)\\'"
                    filename)
      (substring filename 0 (match-beginning 0))
    filename))

(defun replay-debbugs-step1 ()
  (interactive)
  (let ((case-fold-search nil)
        (default-directory (expand-file-name "~/src/debbugs"))
        (all-files nil))
    (dolist (flist (seq-group-by
                    #'replay-debbugs-basename
                    (process-lines "git" "ls-files" "--modified" "--others")))
      (let ((fname (pop flist)))
        (setq flist
              (cl-sort (mapcar (lambda (f)
                                 (cons f (file-attribute-modification-time
                                          (file-attributes f))))
                               flist)
                       #'time-less-p :key #'cdr))
        (when (and (assoc fname flist) (file-exists-p fname))
          (rename-file fname (concat fname ".FINAL"))
          (setcar (assoc fname flist) (concat fname ".FINAL")))
        (push flist all-files)))
    (setq replay-debbugs-file-versions-list
          (cl-sort (apply #'append all-files) #'time-less-p :key #'cdr))
    (bind-key "<f12>" 'replay-debbugs-step2)))

(defun replay-debbugs-step2 ()
  (interactive)
  (pcase-let* ((case-fold-search nil)
               (default-directory (expand-file-name "~/src/debbugs"))
               (`(,file . ,timestamp) (car replay-debbugs-file-versions-list))
               (base (replay-debbugs-basename file)))
    (copy-file file base t t t t)
    (let ((msg
           (if (not (member base (process-lines "git" "ls-files" "--modified" "--others")))
               "Nothing to do for %S"
             (magit-stage-file base)
             (setq magit-commit-arguments
                   (list (format-time-string "--date=%F %T" timestamp)))
             "Staged %S")))
      (delete-file file)
      (message msg (pop replay-debbugs-file-versions-list)))))