;; Copyright (c) 2013 Francois Fleuret
;; Written by Francois Fleuret <francois@fleuret.org>
;;
;; This file is part of mymail.
;;
;; mymail is free software: you can redistribute it and/or modify it
;; under the terms of the GNU General Public License version 3 as
;; published by the Free Software Foundation.
;;
;; mymail 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 mymail.  If not, see <http://www.gnu.org/licenses/>.

;; You may want to add
;;
;; (add-to-list 'recentf-exclude "/tmp/mymail-vm-.*\.mbox")
;;
;; to your .emacs
;;
;; I also use
;;
;; (define-key vm-summary-mode-map "\\" 'mymail/vm-visit-folder)
;;
;; So that pressing "\" in the summary start a search with mymail

(defgroup mymail ()
  "Command to visit a folder built on-the-fly with mymail"
  :version "0.9.10")

(defcustom mymail/default-additional-search-requests ""
  "Comma-separated list of search requests to add to any search"
  :type 'string
  :group 'mymail)

(defcustom mymail/default-search-request nil
  "Default request to use in place of the empty search"
  :type 'string
  :group 'mymail)

(defun mymail/vm-visit-folder (param)
  "Read a comma-separated list of search requests for mymail,
create a temporary mbox with the resulting mails, and open it in
vm with `vm-visit-folder'.

If the request string is empty, use
`mymail/default-search-request' instead.

The string `mymail/default-additional-search-requests' is automatically
concatenated to the provided request, except if the request is
prefaced with `\\'."
  (interactive
   (list (read-string "mymail-vm: " nil 'mymail-vm-history)))

  (if (string= param "")
      (if mymail/default-search-request
          (setq param mymail/default-search-request)
        (error "mymail error: empty search")))

  (let ((n 1)
        (mbox-name nil)

        (search-args
         (apply 'nconc
                (mapcar
                 (lambda (searche-request)
                   (if (not (string= searche-request ""))
                       (list "--search" searche-request)))
                 (if (string= (substring param 0 1) "\\")
                     (split-string (substring param 1 nil) ",")
                   (split-string (concat param ","
                                         mymail/default-additional-search-requests) ","))
                 )))
        )

    (while (get-file-buffer (setq mbox-name (format "/tmp/mymail-vm-%d.mbox" n)))
      (setq n (+ n 1)))

    ;; (message (prin1-to-string
              ;; (nconc (list "mymail"
                           ;; "--output" mbox-name
                           ;; "--default-search" "p"
                           ;; "--nb-mails-max" "500")
                     ;; search-args))
             ;; )

    (if (= (apply 'call-process
                  (nconc (list "mymail" nil '(nil "/tmp/mymail.err") nil
                               "--output" mbox-name
                               "--default-search" "p"
                               "--nb-mails-max" "500")
                         search-args))
           0)
        (vm-visit-folder mbox-name t)

      ;; (message "mymail failed. See /tmp/mymail.err"))

      (message (with-temp-buffer
                 (insert-file-contents "/tmp/mymail.err")
                 (replace-string "\n" " ")
                 (buffer-string)))
      )
    ))