;;; wiki-utils.el -- wiki utility functions -*- lexical-binding: t -*-

;; Copyright (C) 2023 Free Software Foundation.

;; Author: Yuchen Pei <id@ypei.org>
;; Package-Requires: ((emacs "28.2"))

;; This file is part of wiki.el.

;; wiki.el is free software: you can redistribute it and/or modify it under
;; the terms of the GNU Affero General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; wiki.el 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 Affero General
;; Public License for more details.

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

;;; Commentary:

;; wiki utility functions.

;;; Code:
(defvar wiki-download-dir "~/Downloads")

(defun wiki-fetch-url (url)
  "Fetch url and returns the buffer."
  (interactive "sURL: ")
  (let ((file-name (expand-file-name (wiki-make-file-name-from-url url)
                                     wiki-download-dir)))
    (url-retrieve url 'wiki-fetch-url-save-and-switch (list file-name)))
  )

(defun wiki-fetch-url-save-and-switch (status file-name)
  (unless (plist-get status :error)
    (wiki-delete-http-header)
    (write-file file-name)
    (let ((coding-system-for-read 'utf-8))
      (revert-buffer t t))
    (switch-to-buffer (current-buffer))))

(defun wiki-delete-http-header ()
  (delete-region (point-min) (progn (wiki-skip-http-header) (point))))

(defun wiki-skip-http-header ()
  (goto-char (point-min))
  (re-search-forward "\r?\n\r?\n"))

(defun wiki-make-file-name-from-url (url)
  (file-name-nondirectory
   (directory-file-name
    (car (url-path-and-query (url-generic-parse-url
                              (url-unhex-string url)))))))

(provide 'wiki-utils)
;;; wiki-utils.el ends here