;; notmuch-lib.el --- common variables, functions and function declarations
;;
;; Copyright © Carl Worth
;;
;; This file is part of Notmuch.
;;
;; Notmuch 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.
;;
;; Notmuch 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 Notmuch.  If not, see <http://www.gnu.org/licenses/>.
;;
;; Authors: Carl Worth <cworth@cworth.org>

;; This is an part of an emacs-based interface to the notmuch mail system.

(defvar notmuch-command "notmuch"
  "Command to run the notmuch binary.")

(defgroup notmuch nil
  "Notmuch mail reader for Emacs."
  :group 'mail)

(defcustom notmuch-search-oldest-first t
  "Show the oldest mail first when searching."
  :type 'boolean
  :group 'notmuch)

;;

(defcustom notmuch-saved-searches nil
  "A list of saved searches to display."
  :type '(alist :key-type string :value-type string)
  :group 'notmuch)

(defvar notmuch-folders nil
  "Deprecated name for what is now known as `notmuch-saved-searches'.")

(defun notmuch-saved-searches ()
  "Common function for querying the notmuch-saved-searches variable.

We do this as a function to support the old name of the
variable (`notmuch-folders') as well as for the default value if
the user hasn't set this variable with the old or new value."
  (if notmuch-saved-searches
      notmuch-saved-searches
    (if notmuch-folders
	notmuch-folders
      '(("inbox" . "tag:inbox")
	("unread" . "tag:unread")))))

(defun notmuch-version ()
  "Return a string with the notmuch version number."
  (let ((long-string
	 ;; Trim off the trailing newline.
	 (substring (shell-command-to-string
		     (concat notmuch-command " --version"))
		    0 -1)))
    (if (string-match "^notmuch\\( version\\)? \\(.*\\)$"
		      long-string)
	(match-string 2 long-string)
      "unknown")))

(defun notmuch-config-get (item)
  "Return a value from the notmuch configuration."
  ;; Trim off the trailing newline
  (substring (shell-command-to-string
	      (concat notmuch-command " config get " item))
	      0 -1))

(defun notmuch-database-path ()
  "Return the database.path value from the notmuch configuration."
  (notmuch-config-get "database.path"))

(defun notmuch-user-name ()
  "Return the user.name value from the notmuch configuration."
  (notmuch-config-get "user.name"))

(defun notmuch-user-primary-email ()
  "Return the user.primary_email value from the notmuch configuration."
  (notmuch-config-get "user.primary_email"))

(defun notmuch-user-other-email ()
  "Return the user.other_email value (as a list) from the notmuch configuration."
  (split-string (notmuch-config-get "user.other_email") "\n"))

(defun notmuch-kill-this-buffer ()
  "Kill the current buffer."
  (interactive)
  (kill-buffer (current-buffer)))

;;

(defun notmuch-common-do-stash (text)
  "Common function to stash text in kill ring, and display in minibuffer."
  (kill-new text)
  (message "Stashed: %s" text))

;;

;; XXX: This should be a generic function in emacs somewhere, not
;; here.
(defun point-invisible-p ()
  "Return whether the character at point is invisible.

Here visibility is determined by `buffer-invisibility-spec' and
the invisible property of any overlays for point. It doesn't have
anything to do with whether point is currently being displayed
within the current window."
  (let ((prop (get-char-property (point) 'invisible)))
    (if (eq buffer-invisibility-spec t)
	prop
      (or (memq prop buffer-invisibility-spec)
	  (assq prop buffer-invisibility-spec)))))

(defun notmuch-remove-if-not (predicate list)
  "Return a copy of LIST with all items not satisfying PREDICATE removed."
  (let (out)
    (while list
      (when (funcall predicate (car list))
        (push (car list) out))
      (setq list (cdr list)))
    (nreverse out)))

; This lets us avoid compiling these replacement functions when emacs
; is sufficiently new enough to supply them alone. We do the macro
; treatment rather than just wrapping our defun calls in a when form
; specifically so that the compiler never sees the code on new emacs,
; (since the code is triggering warnings that we don't know how to get
; rid of.
;
; A more clever macro here would accept a condition and a list of forms.
(defmacro compile-on-emacs-prior-to-23 (form)
  "Conditionally evaluate form only on emacs < emacs-23."
  (list 'when (< emacs-major-version 23)
	form))

;; Compatibility functions for versions of emacs before emacs 23.
;;
;; Both functions here were copied from emacs 23 with the following copyright:
;;
;; Copyright (C) 1985, 1986, 1992, 1994, 1995, 1999, 2000, 2001, 2002, 2003,
;;   2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
;;
;; and under the GPL version 3 (or later) exactly as notmuch itself.
(compile-on-emacs-prior-to-23
 (defun apply-partially (fun &rest args)
   "Return a function that is a partial application of FUN to ARGS.
ARGS is a list of the first N arguments to pass to FUN.
The result is a new function which does the same as FUN, except that
the first N arguments are fixed at the values with which this function
was called."
   (lexical-let ((fun fun) (args1 args))
     (lambda (&rest args2) (apply fun (append args1 args2))))))

(compile-on-emacs-prior-to-23
 (defun mouse-event-p (object)
   "Return non-nil if OBJECT is a mouse click event."
   (memq (event-basic-type object) '(mouse-1 mouse-2 mouse-3 mouse-movement))))

;; This variable is used only buffer local, but it needs to be
;; declared globally first to avoid compiler warnings.
(defvar notmuch-show-process-crypto nil)
(make-variable-buffer-local 'notmuch-show-process-crypto)

(provide 'notmuch-lib)

