;; (C) Copyright Collin J. Doering 2014
;;
;; 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 3 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, see <http://www.gnu.org/licenses/>.

;; File: mu4e.el
;; Author: Collin J. Doering <collin.doering@rekahsoft.ca>
;; Date: Oct 22, 2014

;; Setup email using mu4e (offlineimap in the background) and smtpmail
(require 'mu4e)
(require 'smtpmail)

(setq mail-user-agent 'mu4e-user-agent
      mu4e-get-mail-command "mbsync -a"
      mu4e-update-interval 300
      mu4e-user-mail-address-list (list "collin.doering@gmail.com" "rekahsoft@gmail.com")
      message-kill-buffer-on-exit t
      mu4e-use-fancy-chars t
      mu4e-sent-messages-behavior 'delete
      mu4e-confirm-quit nil
      mu4e-headers-date-format "%d/%b/%Y %H:%M" ; date format
      message-signature "Collin J. Doering\n\nhttp://rekahsoft.ca\nhttp://blog.rekahsoft.ca\n"
      mu4e-compose-signature message-signature
      message-signature-insert-empty-line t
      mu4e-html2text-command "pandoc -f html -t asciidoc"

      mu4e-view-show-images t
      mu4e-view-image-max-width 800

      ;; Default email for smtp and mu4e
      user-mail-address "collin.doering@gmail.com"
      
      ;; Setup mu4e default sent and draft folders
      mu4e-sent-folder "/collin.doering-gmail/[Gmail].Sent"
      mu4e-drafts-folder "/collin.doering-gmail/[Gmail].Drafts"

      ;; Set location of maildir
      mu4e-maildir "~/.mail"
      
      ;; Setup smtp defaults
      user-full-name "Collin J. Doering"
      smtpmail-smtp-server "smtp.gmail.com"
      smtpmail-smtp-service 587
      smtpmail-auth-credentials "~/.authinfo.gpg"
      smtpmail-stream-type 'starttls
      smtpmail-debug-info t
      message-send-mail-function 'smtpmail-send-it)

;; Override default mu4e-bookmarks with custom ones
(setq mu4e-bookmarks
      '(("flag:unread AND NOT flag:trashed AND NOT maildir:/collin.doering-gmail/[Gmail].Spam AND NOT maildir:/rekahsoft-gmail/[Gmail].Spam" "Unread messages" ?u)
        ("date:today..now AND NOT maildir:/collin.doering-gmail/[Gmail].Spam AND NOT maildir:/rekahsoft-gmail/[Gmail].Spam" "Today's messages" ?t)
        ("date:7d..now AND NOT maildir:/collin.doering-gmail/[Gmail].Spam AND NOT maildir:/rekahsoft-gmail/[Gmail].Spam" "Last 7 days" ?w)
        ("mime:image/*" "Messages with images" ?p)

        ;; For collin.doering-gmail maildir
        ("flag:unread AND maildir:/collin.doering-gmail/INBOX AND NOT flag:trashed AND NOT maildir:/collin.doering-gmail/[Gmail].Spam" "Unread messages to collin.doering-gmail" ?z)
        ("date:today..now AND maildir:/collin.doering-gmail/INBOX AND NOT maildir:/collin.doering-gmail/[Gmail].Spam" "Today's messages to collin.doering-gmail" ?x)
        ("date:7d..now AND maildir:/collin.doering-gmail/INBOX AND NOT maildir:/collin.doering-gmail/[Gmail].Spam" "Last 7 days (collin.doering-gmail)" ?c)
        ("mime:image/* AND maildir:/collin.doering-gmail/INBOX" "Messages with images to collin.doering-gmail" ?v)

        ;; For rekahsoft-gmail maildir
        ("flag:unread AND maildir:/rekahsoft-gmail/INBOX AND NOT flag:trashed AND NOT maildir:/rekahsoft-gmail/[Gmail].Spam" "Unread messages to rekahsoft-gmail" ?m)
        ("date:today..now AND maildir:/rekahsoft-gmail/INBOX AND NOT maildir:/rekahsoft-gmail/[Gmail].Spam" "Today's messages to rekahsoft-gmail" ?,)
        ("date:7d..now AND maildir:/rekahsoft-gmail/INBOX AND NOT maildir:/rekahsoft-gmail/[Gmail].Spam" "Last 7 days (rekahsoft-gmail)" ?.)
        ("mime:image/* AND maildir:/rekahsoft-gmail/INBOX" "Messages with images to rekahsoft-gmail" ?/)))

;; TODO: consolidate my-mu4e-account-alist and smtp-accounts
(defvar my-mu4e-account-alist
  '(("collin.doering-gmail"
     (mu4e-sent-folder "/collin.doering-gmail/[Gmail].Sent")
     (mu4e-drafts-folder "/collin.doering-gmail/[Gmail].Drafts")
     (user-mail-address "collin.doering@gmail.com"))
    ("rekahsoft-gmail"
     (mu4e-sent-folder "/rekahsoft-gmail/[Gmail].Sent")
     (mu4e-drafts-folder "/rekahsoft-gmail/[Gmail].Drafts")
     (user-mail-address "rekahsoft@gmail.com"))))

(defun my-mu4e-set-account ()
  "Set the account for composing a message."
  (let* ((account
          (if mu4e-compose-parent-message
              (let ((maildir (mu4e-message-field mu4e-compose-parent-message :maildir)))
                (string-match "/\\(.*?\\)/" maildir)
                (match-string 1 maildir))
            (completing-read (format "Compose with account: (%s) "
                                     (mapconcat #'(lambda (var) (car var)) my-mu4e-account-alist "/"))
                             (mapcar #'(lambda (var) (car var)) my-mu4e-account-alist)
                             nil t nil nil (caar my-mu4e-account-alist))))
         (account-vars (cdr (assoc account my-mu4e-account-alist))))
    (if account-vars
        (mapc #'(lambda (var)
                  (set (car var) (cadr var)))
              account-vars)
      (error "No email account found"))))

(add-hook 'mu4e-compose-pre-hook 'my-mu4e-set-account)

;; Attach files using dired using 'C-c RET C-a'
;; Thanks to: http://www.djcbsoftware.nl/code/mu/mu4e/Attaching-files-with-dired.html#Attaching-files-with-dired
(require 'gnus-dired)
;; make the `gnus-dired-mail-buffers' function also work on
;; message-mode derived modes, such as mu4e-compose-mode
(defun gnus-dired-mail-buffers ()
  "Return a list of active message buffers."
  (let (buffers)
    (save-current-buffer
      (dolist (buffer (buffer-list t))
	(set-buffer buffer)
	(when (and (derived-mode-p 'message-mode)
		(null message-sent-message-via))
	  (push (buffer-name buffer) buffers))))
    (nreverse buffers)))

(setq gnus-dired-mail-mode 'mu4e-user-agent)
(add-hook 'dired-mode-hook 'turn-on-gnus-dired-mode)

;; Setup mu4e-maildirs-extension
(require 'mu4e-maildirs-extension)
(mu4e-maildirs-extension)

(setq smtp-accounts
      '(("collin.doering@gmail.com" "Collin J. Doering" "smtp.gmail.com")
	("rekahsoft@gmail.com" "rekahsoft" "smtp.gmail.com")))

(defun my-change-smtp ()
  (save-excursion
    (loop with from = (save-restriction
			(message-narrow-to-headers)
			(message-fetch-field "from"))
	  for (addr fname server) in smtp-accounts
	  when (string-match addr from)
	  do (setq user-mail-address addr
		   user-full-name fname
		   smtpmail-smtp-server server
		   smtpmail-smtp-user addr))))

(defadvice smtpmail-via-smtp
  (before change-smtp-by-message-from-field (recipient buffer &optional ask) activate)
  (with-current-buffer buffer (my-change-smtp)))

(ad-activate 'smtpmail-via-smtp)

;; Set environment variables set by gpg-agent --daemon in ~/.gpg-agent-info
;; TODO: perhaps better error handling if ~/.gpg-agent-info doesn't exist
(mapc (lambda (x) (setenv (car x) (cadr x)))
      (with-temp-buffer
         (insert-file-contents "~/.gpg-agent-info")
         (mapcar (lambda (x) (split-string x "=" t)) (split-string (buffer-string) "\n" t))))