;;; myfeed.el --- My RSS reader -*- lexical-binding: t; -*-

;; Author: iamtoaster
;; Version: 0.0.0
;; Package-Requires: ()
;; Homepage: 
;; Keywords: rss, url

;; 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.

;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; An RSS feed reader inspired by elfeed. Very early WIP.

;;; Code:

(defvar myreader-feeds '()
  "Alist of the form (NAME . LINK) of RSS feeds.")

(defvar myreader--feed-buffers '()
  "Alist of buffers in which the asynchronously retrieved pages are
written.")

(defvar myreader--feed-cache '()
  "A list of retrieved entries.")

;; (defun myreader--eww-render-buffer ()
;;   "Render the current buffer in EWW."
;;   (interactive)
;;   (let* ((html (buffer-substring-no-properties (point-min) (point-max)))
;; 	(source (buffer-name))
;; 	(buf (generate-new-buffer (concat "RSS: " source))))
;;     (with-current-buffer buf
;;       (insert html)
;;       (goto-char (point-min))
;;       (eww-display-html 'utf-8 source nil nil buf))
;;     (switch-to-buffer buf)))

(defun myreader--render-entry ()
  (with-current-buffer retr-buf
    (message "%s" (buffer-substring (point-min) (point-max)))))

(defun myreader--update-feed (name)
  (let ((buf (alist-get name myreader--feed-buffers)))
    ;; TODO figure out a good way to put the thing in cache and then use it
    (message "Feed %s; Parsed %s" name (libxml-parse-html-region (point)))))

(setq myreader-feeds '((scour . "https://scour.ing/@DiToast/rss.xml")))

(defun myreader-update-feeds (&optional force)
  "Goes through all the feeds defined in `myreader-feeds' and updates them
if necessary. If FORCE is non-nil, updates them unconditionally."
  (dolist (entry myreader-feeds)
    (let ((name (car entry))
          (link (cdr entry)))
      (let ((cache-entry (alist-get name myreader--feed-cache)))
        ;; TODO check if entry exists in cache -> check if ttl expired
        ;; (if (and cache-entry (alist-get ))
        ;; TODO if updating async retrieve the LINK through myreader--feed-buffers
        (setq myreader--feed-buffers
              (cons
               (cons
                name
                (url-retrieve link (lambda (&rest keys) (myreader--update-feed name))))
               myreader--feed-buffers))))))

(defun myreader-revert-item-buffer ()
  "Reverts the buffer containing the list of RSS entry items from
`myreader--feed-cache'."
  (interactive)
  ;; TODO go through cache -> check ttl -> update feed if necessary
  ;; TODO add the items to the tabulated list
  ())

;; (setq retr-buf (url-retrieve "https://scour.ing/@DiToast/rss.xml"
;;                (lambda (&rest keys) (render-buff))))

(provide 'myfeed)

;;; myfeed.el ends here