;;; auth-get.el --- 
;; 
;; Filename: auth-get.el
;; Description: 
;; Author: Christian Giménez with help from Tiago Charters de Azevedo.
;; Maintainer: 
;; Created: jue ene 12 14:53:35 2012 (-0300)
;; Version: 
;; Last-Updated: 
;;           By: 
;;     Update #: 0
;; URL: 
;; Keywords: 
;; Compatibility: 
;; 
;; Features that might be required by this library:
;;
;;   None
;;
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;; 
;;; Commentary: 
;; 
;; 
;; 
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;; 
;;; Change Log:
;; 
;; 
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;; 
;; 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, 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; see the file COPYING.  If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth
;; Floor, Boston, MA 02110-1301, USA.
;; 
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;; 
;;; Code:

(require 'url)
(require 'json)

(defun d-get-auth-token (url)
  "Find the first authenticity token from the given URL.
This looks for the <meta> tag in the HTML page that correspond to the name \"csrf-token\".
The auth-token will be saved in d-auth-token as well."
  (let (
	(url-request-extra-headers
	 '(("Content-Type" . "application/x-www-form-urlencoded")
	   ("Accept-Language" . "en")
	   ("Accept-Charset" . "UTF-8"))
	 )
	)	
    (url-retrieve url 'd-find-auth-token)
    )
  )

(defun d-find-auth-token (status)
  "Just look for the authenticity token in the buffer. 
This is used as a \"callback\" function for `url-retrieve'."
  ;; DEBUGING PURPOSE ONLY:
  ;;(switch-to-buffer (current-buffer))
  
  ;; Look for the first Auth-token
  (save-excursion
    (goto-char (point-min))
    (search-forward-regexp "<meta name=\"csrf-token\" content=\"\\(.*\\)\"/>")
    (setq d-auth-token (match-string-no-properties 1))
    )
  ;;(kill-buffer (current-buffer))

  d-auth-token
  )

(defvar d-pass nil
  "Diaspora temporal Password")

(defvar d-user nil
  "Diaspora temporal User"
  )

(defvar d-auth-token nil
  "Diaspora temporal authenticity token"
  )
  

(defun d-send-login ()
  "Send login information. 
First call `d-get-login-page' for getting the authenticity token(`d-auth-token')."
  (interactive)  

  (let (
	(url-request-method "POST")
	(url-request-extra-headers
	 '(("Content-Type" . "application/x-www-form-urlencoded")
	   ("Accept-Language" . "en")
	   ("Accept-Charset" . "UTF-8")	   	   
	   ))
	(url-request-data
	 (mapconcat (lambda (arg)
		      (concat (url-hexify-string (car arg)) "=" (url-hexify-string (cdr arg))))
		    (list (cons "user[username]" d-user) 
			  (cons "user[password]" d-pass)
			  (cons "user[remember_me]" "1")
			  (cons "commit" "Entrar")
			  (cons "authenticity_token" d-auth-token)	 
			  )
		    "&"))
	 )
    (url-retrieve d-login-page-url 'd-show-stream)
    )
  )

(defun d-show-stream (status &optional new-buffer-name)
  "Show what was recieved in a new buffer.
If new-buffer-name is given then, the new buffer will have that name, 
if not, the buffer called \"Diáspora Stream\" will be re-used or created if needed."

  ;; new-buffer-name has been given? if not, use "Diáspora Stream" as name.
  (unless new-buffer-name
    (setq new-buffer-name "Diáspora Stream")
    )
  (let ((buffer (get-buffer-create new-buffer-name))
	(text (buffer-string))
	(buf-kill (current-buffer))
	)    

    ;; copy text and switch
    (switch-to-buffer buffer)
    (insert text)    
    
    ;; kill the http buffer
    (kill-buffer buf-kill)
    )
  )

(defvar d-login-page-url "https://joindiaspora.com/users/sign_in"
  "Diáspora Login page"
  )

(defun d-get-login-page ()
  "Get the Diáspora login page for getting the auth-token necessary."
  (d-get-auth-token d-login-page-url)
  (message "Getting authenticity token... done.")
  (message d-auth-token)
  )

(defun d-make-login (&optional user pass)
  (interactive)

  (if user
      (setq d-user user) ;; Parameter user exists
    (setq d-user (read-string "User?"))
    )

  (if pass
      (setq d-pass pass) ;; Parameter pass exists
    (setq d-pass (read-passwd "Password?"))
    )  
    
  ;; We need the auth-token and cookies...
  (d-get-login-page)
  ;;(d-send-login)    
  )

(defun d-get-url (url buffer-name)
  "Get the Diáspora URL and leave it in a new buffer."
  (let (
	(url-request-extra-headers
	 '(("Content-Type" . "application/x-www-form-urlencoded")
	   ("Accept-Language" . "en")
	   ("Accept-Charset" . "UTF-8")	   	   
	   ))
	 )
    (url-retrieve url 'd-show-stream (cons buffer-name nil)) 
    )
  )

(defvar d-entry-stream-url "http://joindiaspora.com/stream.json"
  "JSON version of the entry stream(the main stream).")

(defun d-get-url-entry-stream (url)
  "Get the Diáspora URL and leave it in a new buffer."
  (let (
	(url-request-extra-headers
	 '(("Content-Type" . "application/x-www-form-urlencoded")
	   ("Accept-Language" . "en")
	   ("Accept-Charset" . "UTF-8")	   	   
	   ))
	 )
    (url-retrieve-synchronously url) 
    )
  )

(defun d-get-entry-stream ()
  "Show the entry stream. 
First look for the JSON file at `d-entry-stream-url' and then parse it.
I expect to be already logged in. For that you can use `d-make-login'."
  (interactive)
  (let (
	(buff (d-get-url-entry-stream d-entry-stream-url))
	)
    (with-current-buffer buff
      ;; Delete the HTTP header...
      (goto-char (point-min))
      (search-forward "\n\n")      
      (delete-region (point-min) (match-beginning 0))
      ;; Parse JSON...
      (d-parse-json)
      )
    ;; Delete HTTP Buffer
    (kill-buffer buff)
    )
  )

(defun d-show-message (parsed-message &optional buffer)
  "Show a parsed message in a given buffer."
  (with-current-buffer buffer
    (let (
	  (name (cdr (assoc 'name (assoc 'author parsed-message))))
	  (diaspora_id (cdr (assoc 'diaspora_id (assoc 'author parsed-message))))
	  (text (cdr (assoc 'text parsed-message)))
	  (date (cdr (assoc 'created_at parsed-message)))
	  (amount-comments (cdr (assoc 'comments_count parsed-message)))
	  (amount-likes (cdr (assoc 'likes_count parsed-message)))
	  ;; We can look for more data, including the last 3 comments!
	  )
	  
      (insert (format "---\n%s(%s):\n%s\n\n" name diaspora_id text))
      )
    )
  )

(defun d-parse-json (&optional status)
  "Parse de JSON entry stream."
  (goto-char (point-min))
  (let (
	(lstparsed (cdr (assoc 'posts (json-read))))
	(buff (get-buffer-create "*Diáspora*"))
	)
    (switch-to-buffer buff)
    (let (
	  (le (length lstparsed))
	  )
    ;; Show all elements
    
    
      (dotimes (i le)
	(d-show-message (aref lstparsed i) buff)
	)
      )
    )
  )
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;;; auth-get.el ends here