;;; sx-favorites.el --- Starred questions          -*- lexical-binding: t; -*-

;; Copyright (C) 2014  Sean Allred

;; Author: Sean Allred <code@seanallred.com>

;; 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/>.

;;; Commentary:

;;

;;; Code:

(require 'sx-method)
(require 'sx-cache)
(require 'sx-site)
(require 'sx-networks)

(defvar sx-favorite-list-filter
  '((.backoff
     .items
     .quota_max
     .quota_remaining
     question.question_id)
    nil
    none))

(defvar sx-favorites--user-favorite-list nil
  "Alist of questions favorited by the user.

Each element has the form (SITE FAVORITE-LIST).  And each element
in FAVORITE-LIST is the numerical QUESTION_ID.")

(defun sx-favorites--ensure-favorite-list ()
  (unless sx-favorites--user-favorite-list
    (setq sx-favorites--user-favorite-list
          (sx-cache-get
           'question-favorites
           (let ((sites
                  (mapcar (lambda (site)
                            `(,site))
                          sx-network--user-sites)))
             `(quote ,sites))))))

(defun sx-favorites--retrieve-favorites (site)
  "Obtain list of starred QUESTION_IDs for SITE."
  (sx-method-call (format "me/favorites?site=%s" site)
                  nil
                  sx-favorite-list-filter
                  'warn))

(defun sx-favorites--update-site-favorites (site)
  "Update list of starred QUESTION_IDs for SITE.

Writes list to cache QUESTION-FAVORITES."
  (sx-favorites--ensure-favorite-list site)
  (let ((favs (sx-favorites--retrieve-favorites site))
        (site-cell (assoc site
                          sx-favorites--user-favorite-list)))
    (if site-cell
        (setcdr site-cell (mapcar #'cdar favs))
      (push (cons site favs) sx-favorites--user-favorite-list))
  (sx-cache-set 'question-favorites sx-favorites--user-favorite-list)))

(defun sx-favorites-update ()
  "Update all sites retrieved from `sx-network--user-sites'."
  (sx-network--ensure-user)
  (mapc #'sx-favorites--update-site-favorites
        sx-network--user-sites))

(provide 'sx-favorites)
;;; sx-favorites.el ends here

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