;; Message mode
;; This is common to Gnus, mu4e, notmuch, etc.

(setq mm-default-directory "~/temp"     ; Where to save attachments.
      message-kill-buffer-on-exit t
      ;; Sending mail:
      mail-specify-envelope-from t
      mail-envelope-from 'header
      message-send-mail-function 'smtpmail-send-it)

(load "~/personal/mail/smtpmail.el" 'noerror)

;; TODO: Use the following to automatically set the From: field when replying.
;; message-alternative-emails

;; Sign messages by default.
(add-hook 'message-setup-hook 'mml-secure-sign-pgpmime)

(defun message-recipients ()
  "Return a list of all recipients in the message, looking at TO, CC and BCC.

Each recipient is in the format of `mail-extract-address-components'."
  (mapcan (lambda (header)
            (let ((header-value (message-fetch-field header)))
              (and
               header-value
               (mail-extract-address-components header-value t))))
          '("To" "Cc" "Bcc")))

(defun message-all-epg-keys-available-p ()
  "Return non-nil if the pgp keyring has a public key for each recipient."
  (require 'epa)
  (let ((context (epg-make-context epa-protocol)))
    (catch 'break
      (dolist (recipient (message-recipients))
        (let ((recipient-email (cadr recipient)))
          (when (and recipient-email (not (epg-list-keys context recipient-email)))
            (throw 'break nil))))
      t)))

(defun message-sign-encrypt-if-all-keys-available ()
  "Add MML tag to encrypt message when there is a key for each recipient.

Consider adding this function to `message-send-hook' to
systematically send encrypted emails when possible."
  (when (message-all-epg-keys-available-p)
    (mml-secure-message-sign-encrypt)))

;; (add-hook 'message-send-hook #'message-sign-encrypt-if-all-keys-available)

(provide 'init-message)