; notmuch.el --- run notmuch within emacs
;
; 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>
;
; Much of notmuch.el was written by looking at the implementation of
; compile.el from the emacs distribution source which has the
; following copyright and authorsip (and the identical license as
; above):
;
; Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
;   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
;   Free Software Foundation, Inc.

; Authors: Roland McGrath <roland@gnu.org>,
;	    Daniel Pfeiffer <occitan@esperanto.org>

(defvar notmuch-show-mode-map
  (let ((map (make-sparse-keymap)))
    ; I don't actually want all of these toggle commands occupying
    ; keybindings. They steal valuable key-binding space, are hard
    ; to remember, and act globally rather than locally.
    ;
    ; Will be much preferable to switch to direct manipulation for
    ; toggling visibility of these components. Probably using
    ; overlays-at to query and manipulate the current overlay.
    (define-key map "b" 'notmuch-show-toggle-body-read-visible)
    (define-key map "c" 'notmuch-show-toggle-citations-visible)
    (define-key map "h" 'notmuch-show-toggle-headers-visible)
    (define-key map "n" 'notmuch-show-next-message)
    (define-key map "p" 'notmuch-show-previous-message)
    (define-key map "q" 'kill-this-buffer)
    (define-key map "s" 'notmuch-show-toggle-signatures-visible)
    (define-key map "x" 'kill-this-buffer)
    map)
  "Keymap for \"notmuch show\" buffers.")
(fset 'notmuch-show-mode-map notmuch-show-mode-map)

(defvar notmuch-show-message-begin-regexp    "message{")
(defvar notmuch-show-message-end-regexp      "message}")
(defvar notmuch-show-header-begin-regexp     "header{")
(defvar notmuch-show-header-end-regexp       "header}")
(defvar notmuch-show-body-begin-regexp       "body{")
(defvar notmuch-show-body-end-regexp         "body}")
(defvar notmuch-show-attachment-begin-regexp "attachment{")
(defvar notmuch-show-attachment-end-regexp   "attachment}")
(defvar notmuch-show-part-begin-regexp       "part{")
(defvar notmuch-show-part-end-regexp         "part}")
(defvar notmuch-show-marker-regexp "\\(message\\|header\\|body\\|attachment\\|part\\)[{}].*$")

(defvar notmuch-show-id-regexp "ID: \\([^ ]*\\)")

(defun notmuch-show-get-message-id ()
  (save-excursion
    (beginning-of-line)
    (if (not (looking-at notmuch-show-message-begin-regexp))
	(re-search-backward notmuch-show-message-begin-regexp))
    (re-search-forward notmuch-show-id-regexp)
    (buffer-substring (match-beginning 1) (match-end 1))))

(defun notmuch-show-next-message ()
  "Advance point to the beginning of the next message in the buffer.

Before moving, also remove the \"unread\" tag from the current message."
  (interactive)
  (notmuch-call-notmuch-process "tag" "-unread" (concat "id:" (notmuch-show-get-message-id)))
  ; First, ensure we get off the current message marker
  (if (not (eobp))
      (forward-char))
  (re-search-forward notmuch-show-message-begin-regexp nil t)
  ; This dance might look pointless, but it's important. I originally
  ; just had (beginning-of-line) here which looked right on the
  ; display but actually put point all the way back to the first
  ; character of the first invisible line. That is, it put point into
  ; the closing markers of the previous message rather than at the
  ; beginning of the current message. And that in turn meant that
  ; looking up the current message-ID would actually return the
  ; previous message ID.
  ;
  ; So this dance ensures that we're actually on the current message
  ; when it looks like we are.
  (end-of-visible-line)
  (beginning-of-line)
  (recenter 0))

(defun notmuch-show-previous-message ()
  "Advance point to the beginning of the previous message in the buffer."
  (interactive)
  ; First, ensure we get off the current message marker
  (if (not (bobp))
      (previous-line))
  (re-search-backward notmuch-show-message-begin-regexp nil t)
  ; This dance might look pointless, but it's important. I originally
  ; just had (beginning-of-line) here which looked right on the
  ; display but actually put point all the way back to the first
  ; character of the first invisible line. That is, it put point into
  ; the closing markers of the previous message rather than at the
  ; beginning of the current message. And that in turn meant that
  ; looking up the current message-ID would actually return the
  ; previous message ID.
  ;
  ; So this dance ensures that we're actually on the current message
  ; when it looks like we are.
  (end-of-visible-line)
  (beginning-of-line)
  (recenter 0))

(defun notmuch-show-markup-citations-region (beg end)
  (goto-char beg)
  (beginning-of-line)
  (while (< (point) end)
    (let ((beg-sub (point)))
      (if (looking-at ">")
	  (progn
	    (while (looking-at ">")
	      (next-line))
	    (let ((overlay (make-overlay beg-sub (point))))
	      (overlay-put overlay 'invisible 'notmuch-show-citation)
	      (overlay-put overlay 'before-string
			   (concat "[" (number-to-string (count-lines beg-sub (point)))
				   " quoted lines.]")))))
      (if (looking-at "--[ ]?$")
	  (let ((overlay (make-overlay beg-sub end)))
	    (overlay-put overlay 'invisible 'notmuch-show-signature)
	    (overlay-put overlay 'before-string
			 (concat "[" (number-to-string (count-lines beg-sub (point)))
				 "-line signature.]"))
	    (goto-char end)))
      (next-line))))

(defun notmuch-show-markup-body (unread)
  (re-search-forward notmuch-show-body-begin-regexp)
  (next-line 1)
  (beginning-of-line)
  (let ((beg (point)))
    (re-search-forward notmuch-show-body-end-regexp)
    (if (not unread)
	(overlay-put (make-overlay beg (match-beginning 0))
		     'invisible 'notmuch-show-body-read))
    (notmuch-show-markup-citations-region beg (point))
    ))

(defun notmuch-show-markup-header ()
  (re-search-forward notmuch-show-header-begin-regexp)
  (next-line 2)
  (beginning-of-line)
  (let ((beg (point)))
    (re-search-forward notmuch-show-header-end-regexp)
    (overlay-put (make-overlay beg (match-beginning 0))
		 'invisible 'notmuch-show-header)))

(defun notmuch-show-markup-message ()
  (if (re-search-forward notmuch-show-message-begin-regexp nil t)
      (progn
	(let ((unread (looking-at ".*unread$")))
	  (notmuch-show-markup-header)
	  (notmuch-show-markup-body unread)))
    (goto-char (point-max))))

(defun notmuch-show-hide-markers ()
  (save-excursion
    (goto-char (point-min))
    (while (not (eobp))
      (if (re-search-forward notmuch-show-marker-regexp nil t)
	  (progn
	    (overlay-put (make-overlay (match-beginning 0) (+ (match-end 0) 1))
			 'invisible 'notmuch-show-marker))
	(goto-char (point-max))))))

(defun notmuch-show-markup-messages ()
  (save-excursion
    (goto-char (point-min))
    (while (not (eobp))
      (notmuch-show-markup-message)))
  (notmuch-show-hide-markers))

(defun notmuch-show-toggle-citations-visible ()
  "Toggle visibility of citations"
  (interactive)
  (if notmuch-show-citations-visible
      (add-to-invisibility-spec 'notmuch-show-citation)
    (remove-from-invisibility-spec 'notmuch-show-citation))
  (set 'notmuch-show-citations-visible (not notmuch-show-citations-visible))
  ; Need to force the redisplay for some reason
  (force-window-update)
  (redisplay t))

(defun notmuch-show-toggle-signatures-visible ()
  "Toggle visibility of signatures"
  (interactive)
  (if notmuch-show-signatures-visible
      (add-to-invisibility-spec 'notmuch-show-signature)
    (remove-from-invisibility-spec 'notmuch-show-signature))
  (set 'notmuch-show-signatures-visible (not notmuch-show-signatures-visible))
  ; Need to force the redisplay for some reason
  (force-window-update)
  (redisplay t))

(defun notmuch-show-toggle-headers-visible ()
  "Toggle visibility of header fields"
  (interactive)
  (if notmuch-show-headers-visible
      (add-to-invisibility-spec 'notmuch-show-header)
    (remove-from-invisibility-spec 'notmuch-show-header))
  (set 'notmuch-show-headers-visible (not notmuch-show-headers-visible))
  ; Need to force the redisplay for some reason
  (force-window-update)
  (redisplay t))

(defun notmuch-show-toggle-body-read-visible ()
  "Toggle visibility of message bodies of read messages"
  (interactive)
  (if notmuch-show-body-read-visible
      (add-to-invisibility-spec 'notmuch-show-body-read)
    (remove-from-invisibility-spec 'notmuch-show-body-read))
  (set 'notmuch-show-body-read-visible (not notmuch-show-body-read-visible))
  ; Need to force the redisplay for some reason
  (force-window-update)
  (redisplay t))

;;;###autoload
(defun notmuch-show-mode ()
  "Major mode for handling the output of \"notmuch show\""
  (interactive)
  (kill-all-local-variables)
  (set (make-local-variable 'notmuch-show-headers-visible) t)
  (notmuch-show-toggle-headers-visible)
  (set (make-local-variable 'notmuch-show-body-read-visible) t)
  (notmuch-show-toggle-body-read-visible)
  (set (make-local-variable 'notmuch-show-citations-visible) t)
  (notmuch-show-toggle-citations-visible)
  (set (make-local-variable 'notmuch-show-signatures-visible) t)
  (notmuch-show-toggle-signatures-visible)
  (add-to-invisibility-spec 'notmuch-show-marker)
  (use-local-map notmuch-show-mode-map)
  (setq major-mode 'notmuch-show-mode
	mode-name "notmuch-show")
  (setq buffer-read-only t))

(defun notmuch-show (thread-id)
  "Run \"notmuch show\" with the given thread ID and display results."
  (interactive "sNotmuch show: ")
  (let ((buffer (get-buffer-create (concat "*notmuch-show-" thread-id "*"))))
    (switch-to-buffer buffer)
    (notmuch-show-mode)
    (let ((proc (get-buffer-process (current-buffer)))
	  (inhibit-read-only t))
      (if proc
	  (error "notmuch search process already running for query `%s'" query)
	)
      (erase-buffer)
      (goto-char (point-min))
      (save-excursion
	(call-process "notmuch" nil t nil "show" thread-id)
	(notmuch-show-markup-messages)
	)
      )))

(defvar notmuch-search-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "a" 'notmuch-search-archive-thread)
    (define-key map "f" 'notmuch-search-filter)
    (define-key map "n" 'next-line)
    (define-key map "p" 'previous-line)
    (define-key map "q" 'kill-this-buffer)
    (define-key map "s" 'notmuch-search)
    (define-key map "x" 'kill-this-buffer)
    (define-key map "\r" 'notmuch-search-show-thread)
    (define-key map "+" 'notmuch-search-add-tag)
    (define-key map "-" 'notmuch-search-remove-tag)
    (define-key map "<" 'beginning-of-buffer)
    (define-key map ">" 'notmuch-search-goto-last-thread)
    (define-key map "\M->" 'notmuch-search-goto-last-thread)
    map)
  "Keymap for \"notmuch search\" buffers.")
(fset 'notmuch-search-mode-map notmuch-search-mode-map)

(defun notmuch-search-goto-last-thread (&optional arg)
  "Move point to the last thread in the buffer."
  (interactive "^P")
  (end-of-buffer arg)
  (beginning-of-line))

;;;###autoload
(defun notmuch-search-mode ()
  "Major mode for handling the output of \"notmuch search\""
  (interactive)
  (kill-all-local-variables)
  (make-local-variable 'notmuch-search-query-string)
  (use-local-map notmuch-search-mode-map)
  (setq major-mode 'notmuch-search-mode
	mode-name "notmuch-search")
  (setq buffer-read-only t))

(defun notmuch-search-find-thread-id ()
  (save-excursion
    (beginning-of-line)
    (let ((beg (point)))
      (re-search-forward "[a-fA-F0-9]*")
      (filter-buffer-substring beg (point)))))

(defun notmuch-search-markup-this-thread-id ()
  (beginning-of-line)
  (let ((beg (point)))
    (re-search-forward "[a-fA-F0-9]*")
    (forward-char)
    (overlay-put (make-overlay beg (point)) 'invisible 'notmuch-search)))

(defun notmuch-search-markup-thread-ids ()
  (save-excursion
    (goto-char (point-min))
    (while (not (eobp))
      (notmuch-search-markup-this-thread-id)
      (next-line))))

(defun notmuch-search-hide-thread-ids ()
  (interactive)
  (add-to-invisibility-spec 'notmuch-search))

(defun notmuch-search-show-thread-ids ()
  (interactive)
  (remove-from-invisibility-spec 'notmuch-search))

(defun notmuch-search-show-thread ()
  (interactive)
  (notmuch-show (notmuch-search-find-thread-id)))

(defun notmuch-call-notmuch-process (&rest args)
  (let ((error-buffer (get-buffer-create "*Notmuch errors*")))
    (with-current-buffer error-buffer
	(erase-buffer))
    (if (eq (apply 'call-process "notmuch" nil error-buffer nil args) 0)
	(point)
      (progn
	(with-current-buffer error-buffer
	  (let ((beg (point-min))
		(end (- (point-max) 1)))
	    (error (buffer-substring beg end))
	    ))))))

(defun notmuch-search-set-tags (tags)
  (save-excursion
    (end-of-line)
    (re-search-backward "(")
    (forward-char)
    (let ((beg (point))
	  (inhibit-read-only t))
      (re-search-forward ")")
      (backward-char)
      (let ((end (point)))
	(delete-region beg end)
	(insert (mapconcat  'identity tags " "))))))

(defun notmuch-search-get-tags ()
  (save-excursion
    (end-of-line)
    (re-search-backward "(")
    (let ((beg (+ (point) 1)))
      (re-search-forward ")")
      (let ((end (- (point) 1)))
	(split-string (buffer-substring beg end))))))

(defun notmuch-search-add-tag (tag)
  (interactive "sTag to add: ")
  (notmuch-call-notmuch-process "tag" (concat "+" tag) (concat "thread:" (notmuch-search-find-thread-id)))
  (notmuch-search-set-tags (delete-dups (sort (cons tag (notmuch-search-get-tags)) 'string<))))

(defun notmuch-search-remove-tag (tag)
  (interactive "sTag to remove: ")
  (notmuch-call-notmuch-process "tag" (concat "-" tag) (concat "thread:" (notmuch-search-find-thread-id)))
  (notmuch-search-set-tags (delete tag (notmuch-search-get-tags))))

(defun notmuch-search-archive-thread ()
  (interactive)
  (notmuch-search-remove-tag "inbox"))

(defun notmuch-search (query)
  "Run \"notmuch search\" with the given query string and display results."
  (interactive "sNotmuch search: ")
  (let ((buffer (get-buffer-create (concat "*notmuch-search-" query "*"))))
    (switch-to-buffer buffer)
    (notmuch-search-mode)
    (set 'notmuch-search-query-string query)
    (let ((proc (get-buffer-process (current-buffer)))
	  (inhibit-read-only t))
      (if proc
	  (error "notmuch search process already running for query `%s'" query)
	)
      (erase-buffer)
      (goto-char (point-min))
      (save-excursion
	(call-process "notmuch" nil t nil "search" query)
	(notmuch-search-markup-thread-ids)
        ; A well-behaved program ends its output with a newline, but we
        ; don't actually want the blank line at the end of the file.
	(goto-char (point-max))
	(if (looking-at "^$")
	    (delete-backward-char 1)
	  )
	))))

(defun notmuch-search-filter (query)
  "Run \"notmuch search\" to refine the current search results.

A search string will be constructed by appending QUERY to the
current search string, and the results of \"notmuch search\" for
the combined query will be displayed."
  (interactive "sFilter search: ")
  (notmuch-search (concat notmuch-search-query-string " and " query)))

(defun notmuch ()
  "Run notmuch to display all mail with tag of 'inbox'"
  (interactive)
  (notmuch-search "tag:inbox"))

(provide 'notmuch)