;;; org-protocol.el --- Intercept calls from emacsclient to trigger custom actions.
;;
;; Copyright (c) 2008, 2009
;;          Bastien Guerry <bzg AT altern DOT org>,
;;          Daniel German <dmg AT uvic DOT org>,
;;          Sebastian Rose <sebastian_rose AT gmx DOT de>,
;;          Ross Patterson <me AT rpatterson DOT net>
;;          David Moffat
;;          (will be FSF when done)
;;
;;
;; Filename: org-protocol.el
;; Version: 6.25trans
;; Author: Bastien Guerry <bzg AT altern DOT org>
;; Author: Daniel M German <dmg AT uvic DOT org>
;; Author: Sebastian Rose <sebastian_rose AT gmx DOT de>
;; Author: Ross Patterson <me AT rpatterson DOT net>
;; Maintainer: Sebastian Rose <sebastian_rose AT gmx DOT de>
;; Keywords: org, emacsclient, wp

;; This file is not part of GNU Emacs.

;; 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.

;; See <http://www.gnu.org/licenses/>.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Commentary:
;;
;; Intercept calls from emacsclient to trigger custom actions.
;;
;; This is done by advising `server-visit-files' to scann the list of filenames
;; for `org-protocol-the-protocol' and sub-procols defined in
;; `org-protocol-protocol-alist' and `org-protocol-protocol-alist-default'.
;;
;; Any application that supports calling external programs with an URL
;; as argument may be used with this functionality.
;;
;;
;; Usage:
;; ------
;;
;;   1.) Add this to your init file (.emacs probably):
;;
;;       (add-to-list 'load-path "/path/to/org-protocol/")
;;       (require 'org-protocol)
;;
;;   3.) Ensure emacs-server is up and running.
;;   4.) Try this from the command line (adjust the URL as needed):
;;
;;       $ emacsclient \
;;         org-protocol://store-link://http:%2F%2Flocalhost%2Findex.html/The%20title
;;
;;   5.) Optionally add custom sub-protocols and handlers:
;;
;;       (setq org-protocol-protocol-alist
;;             '(("my-protocol"
;;                :protocol "my-protocol"
;;                :function my-protocol-handler-fuction)))
;;
;;       A "sub-protocol" will be found in URLs like this:
;;
;;           org-protocol://sub-protocol://data
;;
;; If it works, you can now setup other applications for using this feature.
;;
;;
;; As of March 2009 Firefox users follow the steps documented on
;; http://kb.mozillazine.org/Register_protocol, Opera setup is described here:
;; http://www.opera.com/support/kb/view/535/
;;
;;
;; Documentation
;; -------------
;;
;; org-protocol.el comes with and installs handlers to open sources of published
;; online content, store and insert the browser's URLs and cite online content
;; by clicking on a bookmark in Firefox, Opera and probably other browsers and
;; applications:
;;
;;   * `org-protocol-open-source' uses the sub-protocol \"open-source\" and maps
;;     URLs to local filenames defined in `org-protocol-project-alist'.
;;
;;   * `org-protocol-store-link' stores an Org-link (if Org-mode is present) and
;;     pushes the browsers URL to the `kill-ring' for yanking. This handler is
;;     triggered through the sub-protocol \"store-link\".
;;
;;   * Call `org-protocol-remember' by using the sub-protocol \"remember\".  If
;;     Org-mode is loaded, emacs will popup a remember buffer and fill the
;;     template with the data provided. I.e. the browser's URL is inserted as an
;;     Org-link of which the page title will be the description part. If text
;;     was select in the browser, that text will be the body of the entry.
;;
;; You may use the same bookmark URL for all those standard handlers and just
;; adjust the sub-protocol used:
;;
;;     location.href='org-protocol://sub-protocol://'+
;;           encodeURIComponent(location.href)+'/'+
;;           encodeURIComponent(document.title)+'/'+
;;           encodeURIComponent(window.getSelection())
;;
;; The handler for the sub-protocol \"remember\" detects an optional template
;; char that, if present, triggers the use of a special template.
;; Example:
;;
;;     location.href='org-protocol://sub-protocol://x/'+ ...
;;
;;  use template ?x.
;;
;; Note, that using double shlashes is optional from org-protocol.el's point of
;; view because emacsclient sqashes the slashes to one.
;;
;;
;; provides: 'org-protocol
;;
;;; Code:

(require 'org)
(require 'url)
(eval-when-compile
  (require 'cl))

(declare-function org-publish-initialize-files-alist "org-publish"
		  (&optional refresh))
(declare-function org-publish-get-project-from-filename "org-publish"
		  (filename &optional up))
(declare-function server-sentinel "server"
		  (proc msg))

(defgroup org-protocol nil
  "Intercept calls from emacsclient to trigger custom actions.

This is done by advising `server-visit-files' to scann the list of filenames
for `org-protocol-the-protocol' and sub-procols defined in
`org-protocol-protocol-alist' and `org-protocol-protocol-alist-default'."
  :version "22.1"
  :group 'convenience
  :group 'org)


;;; Variables:

(defconst org-protocol-protocol-alist-default
  '(("org-remember"    :protocol "remember"    :function org-protocol-remember :kill-client t)
    ("org-store-link"  :protocol "store-link"  :function org-protocol-store-link)
    ("org-open-source" :protocol "open-source" :function org-protocol-open-source))
  "Default protocols to use.
See `org-protocol-protocol-alist' for a description of this variable.")


(defconst org-protocol-the-protocol "org-protocol"
  "This is the protocol to detect if org-protocol.el is loaded.
`org-protocol-protocol-alist-default' and `org-protocol-protocol-alist' hold the
sub-protocols that trigger the required action. You will have to define just one
protocol handler OS-wide (MS-Windows) or per application (Linux). That protocol
handler should call emacsclient.")


;;; User variables:

(defcustom org-protocol-reverse-list-of-files t
  "* The filenames passed on the commandline are passed to the emacs-server in
reversed order. Set to `t' (default) to re-reverse the list, i.e. use the
sequence on the command line. If nil, the sequence of the filenames is
unchanged."
  :group 'org-protocol
  :type 'boolean)


(defcustom org-protocol-project-alist nil
  "* Map URLs to local filenames for `org-protocol-open-source' (open-source).

Each element of this list must be of the form:

  (module-name :property value property: value ...)

where module-name is an arbitrary name. All the values are strings.

Possible properties are:

  :online-suffix     - the suffix to strip from the published URLs
  :working-suffix    - the replacement for online-suffix
  :base-url          - the base URL, e.g. http://www.example.com/project/
                       Last slash required.
  :working-directory - the local working directory. This is, what base-url will
                       be replaced with.

Example:

   (setq org-protocol-project-alist
       '((\"http://orgmode.org/worg/\"
          :online-suffix \".php\"
          :working-suffix \".org\"
          :base-url \"http://orgmode.org/worg/\"
          :working-directory \"/home/user/org/Worg/\")
         (\"http://localhost/org-notes/\"
          :online-suffix \".html\"
          :working-suffix \".org\"
          :base-url \"http://localhost/org/\"
          :working-directory \"/home/user/org/\")))

Consider using the interactive functions `org-protocol-create' and
`org-protocol-create-for-org' to help you filling this variable with valid contents."
  :group 'org-protocol
  :type 'alist)


(defcustom org-protocol-protocol-alist nil
  "* Register custom handlers for org-protocol.

Each element of this list must be of the form:

  (module-name :protocol protocol :function func :kill-client nil)

protocol - protocol to detect in a filename without trailing colon and slashes.
           See rfc1738 section 2.1 for more on this.
           If you define a protocol \"my-protocol\", `org-protocol-check-filename-for-protocol'
           will search filenames for \"org-protocol:/my-protocol:/\"
           and trigger your action for every match. `org-protocol' is defined in
           `org-protocol-the-protocol'. Double and tripple slashes are compressed
           to one by emacsclient.

function - function that handles requests with protocol and takes exactly one
           argument: the filename with all protocols stripped. If the function
           returns nil, emacsclient and -server do nothing. Any non-nil return
           value is considered a valid filename and thus passed to the server.

           `org-protocol.el provides some support for handling those filenames,
           if you stay with the conventions used for the standard handlers in
           `org-protocol-protocol-alist-default'. See `org-protocol-split-data'.

kill-client - If t, kill the client immediately, once the sub-protocol is
           detected. This is neccessary for actions that can be interupted by
           `C-g' to avoid dangeling emacsclients. Note, that all other command
           line arguments but the this one will be discarded, greedy handlers
           still receive the whole list of arguments though.

Here is an example:

  (setq org-protocol-protocol-alist
      '((\"my-protocol\"
         :protocol \"my-protocol\"
         :function my-protocol-handler-fuction)
        (\"your-protocol\"
         :protocol \"your-protocol\"
         :function your-protocol-handler-fuction)))"
  :group 'org-protocol
  :type '(alist))


;;; Helper functions:

(defun org-protocol-sanitize-uri (uri)
  "emacsclient compresses double and tripple slashes.
Slashes are sanitized to double slashes here."
  (when (string-match "^\\([a-z]+\\):/" uri)
    (let* ((splitparts (split-string uri "/+")))
      (setq uri (concat (car splitparts) "//" (mapconcat 'identity (cdr splitparts) "/")))))
  uri)


(defun org-protocol-split-data(data &optional unhexify separator)
  "Split, what a org-protocol handler function gets as only argument.
data is that one argument. Data is splitted at each occurrence of separator
 (regexp). If no separator is specified or separator is nil, assume \"/+\".
The results of that splitting are return as a list. If unhexify is non-nil,
hex-decode each split part."
  (let* ((sep (or separator "/+"))
         (split-parts (split-string data sep)))
    (if unhexify
        (mapcar 'url-unhex-string split-parts)
      split-parts)))


(defun org-protocol-flatten-greedy (param-list &optional strip-path replacement)
  "Greedy handlers might recieve a list like this from emacsclient:
 '( (\"/dir/org-protocol:/greedy:/~/path1\" (23 . 12)) (\"/dir/param\")
where \"/dir/\" is the absolute path to emacsclients working directory. This
function transforms it into a flat list utilizing `org-protocol-flatten' and
transforms the elements of that list as follows:

If strip-path is non-nil, remove the \"/dir/\" prefix from all members of
param-list.

If replacement is string, replace the \"/dir/\" prefix with it.

The first parameter, the one that contains the protocols, is always changed.
Everything up to the end of the protocols is stripped.

Note, that this function will always behave as if
`org-protocol-reverse-list-of-files' was set to t and the returned list will
reflect that. I.e. emacsclients first parameter will be the first one in the
returned list."
(let* ((l (org-protocol-flatten (if org-protocol-reverse-list-of-files
				    param-list
				  (reverse param-list))))
      (trigger (car l))
      (len 0)
      dir
      ret)
  (when (string-match "^\\(.*\\)\\(org-protocol:/+[a-zA-z0-9][-_a-zA-z0-9]*:/+\\)\\(.*\\)" trigger)
    (setq dir (match-string 1 trigger))
    (setq len (length dir))
    (setcar l (concat dir (match-string 3 trigger))))
  (if strip-path
      (progn
       (dolist (e l ret)
         (setq ret
               (append ret 
                       (list
                        (if (stringp e)
                            (if (stringp replacement)
                                (setq e (concat replacement (substring e len)))
                              (setq e (substring e len)))
                          e)))))
       ret)
    l)))


(defun org-protocol-flatten (l)
  "Greedy handlers might recieve a list like this from emacsclient:
 '( (\"/dir/org-protocol:/greedy:/~/path1\" (23 . 12)) (\"/dir/param\")
where \"/dir/\" is the absolute path to emacsclients working directory. This
function transforms it into a flat list."
  (if (null l) ()
    (if (listp l)
       (append (org-protocol-flatten (car l)) (org-protocol-flatten (cdr l)))
      (list l))))

;;; Standard protocol handlers:

(defun org-protocol-store-link (fname)
  "Process an org-protocol://store-link:// style url
and store a browser URL as an org link. Also pushes the links URL to the
`kill-ring'.

The location for a browser's bookmark has to look like this:

  javascript:location.href='org-protocol://store-link://'+ \\
        encodeURIComponent(location.href)
        encodeURIComponent(document.title)+'/'+ \\

Don't use `escape()'! Use `encodeURIComponent()' instead. The title of the page
could contain slashes and the location definitely will.

The sub-protocol used to reach this function is set in
`org-protocol-protocol-alist'."
  (let* ((splitparts (org-protocol-split-data fname t))
         (uri (org-protocol-sanitize-uri (car splitparts)))
         (title (cadr splitparts))
         orglink)
    (if (boundp 'org-stored-links)
      (setq org-stored-links (cons (list uri title) org-stored-links)))
    (kill-new uri)
    (message "`%s' to insert new org-link, `%s' to insert `%s'"
             (substitute-command-keys"\\[org-insert-link]")
             (substitute-command-keys"\\[yank]")
             uri))
  nil)


(defun org-protocol-remember  (info)
  "Process an org-protocol://remember:// style url.

The sub-protocol used to reach this function is set in
`org-protocol-protocol-alist'.

This function detects an URL, title and optinal text, separated by '/'
The location for a browser's bookmark has to look like this:

  javascript:location.href='org-protocol://remember://'+ \\
        encodeURIComponent(location.href)+ \\
        encodeURIComponent(document.title)+'/'+ \\
        encodeURIComponent(window.getSelection())

By default the template character ?w is used. But you may prepend the encoded
URL with a character and a slash like so:

  javascript:location.href='org-protocol://org-store-link://b/'+ ...

Now template ?b will be used."

  (if (and (boundp 'org-stored-links)
           (fboundp 'org-remember))
      (let* ((parts (org-protocol-split-data info t))
             (template (or (and (= 1 (length (car parts))) (pop parts)) "w"))
             (url (org-protocol-sanitize-uri (car parts)))
             (type (if (string-match "^\\([a-z]+\\):" url)
                       (match-string 1 url)))
             (title (cadr parts))
             (region (caddr parts))
             (orglink (org-make-link-string url title))
             remember-annotation-functions)
        (setq org-stored-links
              (cons (list url title) org-stored-links))
        (kill-new orglink)
        (org-store-link-props :type type
                              :link url
                              :description title
                              :initial region)
        (raise-frame)
        (org-remember nil (string-to-char template)))
    
    (message "Org-mode not loaded."))
  nil)


(defun org-protocol-open-source (fname)
  "Process an org-protocol://open-source:// style url.

Change a filename by mapping URLs to local filenames as set
in `org-protocol-project-alist'.

The location for a browser's bookmark should look like this:

  javascript:location.href='org-protocol://open-source://'+ \\
        encodeURIComponent(location.href)"

  ;; As we enter this function for a match on our protocol, the return value
  ;; defaults to nil.
  (let ((result nil)
        (f (url-unhex-string fname)))
    (catch 'result
      (dolist (prolist org-protocol-project-alist)
        (let* ((base-url (plist-get (cdr prolist) :base-url))
               (wsearch (regexp-quote base-url)))

          (when (string-match wsearch f)
            (let* ((wdir (plist-get (cdr prolist) :working-directory))
                   (strip-suffix (plist-get (cdr prolist) :online-suffix))
                   (add-suffix (plist-get (cdr prolist) :working-suffix))
                   (start-pos (+ (string-match wsearch f) (length base-url)))
                   (end-pos (string-match
                             (concat (regexp-quote strip-suffix) "\\([?#].*\\)?$") f))
                   (the-file (concat wdir (substring f start-pos end-pos) add-suffix)))
              (if (file-readable-p the-file)
                  (throw 'result the-file))
              (if (file-exists-p the-file)
                  (message "%s: permission denied!" the-file)
                (message "%s: no such file or directory." the-file))))))
      result)))


;;; Core functions:

(defun org-protocol-check-filename-for-protocol (fname restoffiles client)
  "Detect if `org-protocol-the-protocol' and a known sub-protocol is used in fname.
Sub-protocols are registered in `org-protocol-protocol-alist' and
`org-protocol-protocol-alist-default'.
This is, how the matching is done:

  (string-match \"protocol:/+sub-protocol:/+\" ...)

protocol and sub-protocol are regexp-quoted.

If a matching protcol is found, the protcol is stripped from fname and the
result is passed to the protocols function as the only parameter. If the
function returns nil, the filename is removed from the list of filenames
passed from emacsclient to the server.
If the function returns a non nil value, that value is passed to the server
as filename."
  (let ((sub-protocols (append org-protocol-protocol-alist org-protocol-protocol-alist-default)))
    (catch 'fname
      (let ((the-protocol (concat (regexp-quote org-protocol-the-protocol) ":/+")))
        (when (string-match the-protocol fname)
          (dolist (prolist sub-protocols)
            (let ((proto (concat the-protocol (regexp-quote (plist-get (cdr prolist) :protocol)) ":/+")))
              (when (string-match proto fname)
                (let* ((func (plist-get (cdr prolist) :function))
                       (greedy (plist-get (cdr prolist) :greedy))
                       (splitted (split-string fname proto))
                       (result (if greedy restoffiles (cadr splitted))))
                  (if (plist-get (cdr prolist) :kill-client)
		      (server-sentinel client "Greedy org-protocol handler. Killing client."))
                  (when (fboundp func)
                    (unless greedy
                      (throw 'fname (funcall func result)))
                    (funcall func result)
                    (throw 'fname t))))))))
      ;; (message "fname: %s" fname)
      fname)))


(defadvice server-visit-files (before org-protocol-detect-protocol-server activate)
  "Advice server-visit-flist to call `org-protocol-modify-filename-for-protocol'."
  (let ((flist (if org-protocol-reverse-list-of-files
                   (reverse  (ad-get-arg 0))
                 (ad-get-arg 0)))
        (client (ad-get-arg 1)))
    (catch 'greedy
      (dolist (var flist)
        (let ((fname  (expand-file-name (car var)))) ;; `\' to `/' on windows. FIXME: could this be done any better?
          (setq fname (org-protocol-check-filename-for-protocol fname (member var flist)  client))
          (if (eq fname t) ;; greedy? We need the `t' return value.
              (progn
                (ad-set-arg 0 nil)
                (throw 'greedy t))
            (if (stringp fname) ;; probably filename
                (setcar var fname)
              (ad-set-arg 0 (delq var (ad-get-arg 0))))))
        ))))

;;; Org specific functions:

(defun org-protocol-create-for-org ()
  "Create a org-protocol project for the current file's Org-mode project.
This works, if the file visited is part of a publishing project in
`org-publish-project-alist'. This functions calls `org-protocol-create' to do
most of the work."
  (interactive)
  (require 'org-publish)
  (org-publish-initialize-files-alist)
  (let ((all (or (org-publish-get-project-from-filename buffer-file-name))))
    (if all (org-protocol-create (cdr all))
      (message "Not in an org-project. Did mean %s?"
               (substitute-command-keys"\\[org-protocol-create]")))))



(defun org-protocol-create(&optional project-plist)
  "Create a new org-protocol project interactively.
An org-protocol project is an entry in `org-protocol-project-alist'
which is used by `org-protocol-open-source'.
Optionally use project-plist to initialize the defaults for this worglet. If
project-plist is the CDR of an element in `org-publish-project-alist', reuse
:base-directory, :html-extension and :base-extension."
  (interactive)
  (let ((working-dir (expand-file-name(or (plist-get project-plist :base-directory) default-directory)))
        (base-url "http://orgmode.org/worg/")
        (strip-suffix (or (plist-get project-plist :html-extension) ".html"))
        (working-suffix (if (plist-get project-plist :base-extension)
                            (concat "." (plist-get project-plist :base-extension))
                          ".org"))

        (worglet-buffer nil)

        (insert-default-directory t)
        (minibuffer-allow-text-properties nil))

    (setq base-url (read-string "Base URL of published content: " base-url nil base-url t))
    (if (not (string-match "\\/$" base-url))
        (setq base-url (concat base-url "/")))

    (setq working-dir
          (expand-file-name
           (read-directory-name "Local working directory: " working-dir working-dir t)))
    (if (not (string-match "\\/$" working-dir))
        (setq working-dir (concat working-dir "/")))

    (setq strip-suffix
          (read-string
           (concat "Extension to strip from published URLs ("strip-suffix"): ")
                   strip-suffix nil strip-suffix t))

    (setq working-suffix
          (read-string
           (concat "Extension of editable files ("working-suffix"): ")
                   working-suffix nil working-suffix t))

    (when (yes-or-no-p "Save the new worglet to your init file? ")
      (setq org-protocol-project-alist
            (cons `(,base-url . (:base-url ,base-url
                                 :working-directory ,working-dir
                                 :online-suffix ,strip-suffix
                                 :working-suffix ,working-suffix))
                  org-protocol-project-alist))
      (customize-save-variable 'org-protocol-project-alist org-protocol-project-alist))
))

(provide 'org-protocol)
;;; org-protocol.el ends here