;;; helm-net.el --- helm browse url and search web. -*- lexical-binding: t -*-

;; Copyright (C) 2012 ~ 2019 Thierry Volpiatto <thierry.volpiatto@gmail.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/>.

;;; Code:

(require 'cl-lib)
(require 'helm)
(require 'helm-help)
(require 'url)
(require 'xml)
(require 'browse-url)


(defgroup helm-net nil
  "Net related applications and libraries for Helm."
  :group 'helm)

(defcustom helm-google-suggest-default-browser-function nil
  "The browse url function you prefer to use with google suggest.
When nil, use the first browser function available
See `helm-browse-url-default-browser-alist'."
  :group 'helm-net
  :type 'symbol)

(defcustom helm-home-url "https://www.google.com"
  "Default url to use as home url."
  :group 'helm-net
  :type 'string)

(defcustom helm-surfraw-default-browser-function nil
  "The browse url function you prefer to use with surfraw.
When nil, fallback to `browse-url-browser-function'."
  :group 'helm-net
  :type 'symbol)

(defcustom helm-google-suggest-url
  "https://encrypted.google.com/complete/search?output=toolbar&q=%s"
  "URL used for looking up Google suggestions.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defcustom helm-google-suggest-search-url
  "https://encrypted.google.com/search?ie=utf-8&oe=utf-8&q=%s"
  "URL used for Google searching.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defvaralias 'helm-google-suggest-use-curl-p 'helm-net-prefer-curl)
(make-obsolete-variable 'helm-google-suggest-use-curl-p 'helm-net-prefer-curl "1.7.7")

(defcustom helm-net-prefer-curl nil
  "When non--nil use CURL external program to fetch data.
Otherwise `url-retrieve-synchronously' is used."
  :type 'boolean
  :group 'helm-net)

(defcustom helm-surfraw-duckduckgo-url
  "https://duckduckgo.com/lite/?q=%s&kp=1"
  "The duckduckgo url.
This is a format string, don't forget the `%s'.
If you have personal settings saved on duckduckgo you should have
a personal url, see your settings on duckduckgo."
  :type 'string
  :group 'helm-net)

(defcustom helm-search-suggest-action-wikipedia-url
  "https://en.wikipedia.org/wiki/Special:Search?search=%s"
  "The Wikipedia search url.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defcustom helm-search-suggest-action-youtube-url
  "https://www.youtube.com/results?aq=f&search_query=%s"
  "The Youtube search url.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defcustom helm-search-suggest-action-imdb-url
  "http://www.imdb.com/find?s=all&q=%s"
  "The IMDb search url.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defcustom helm-search-suggest-action-google-maps-url
  "https://maps.google.com/maps?f=q&source=s_q&q=%s"
  "The Google Maps search url.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defcustom helm-search-suggest-action-google-news-url
  "https://www.google.com/search?safe=off&prmd=nvlifd&source=lnms&tbs=nws:1&q=%s"
  "The Google News search url.
This is a format string, don't forget the `%s'."
  :type 'string
  :group 'helm-net)

(defcustom helm-google-suggest-actions
  '(("Google Search" . helm-google-suggest-action)
    ("Wikipedia" . (lambda (candidate)
                     (helm-search-suggest-perform-additional-action
                      helm-search-suggest-action-wikipedia-url
                      candidate)))
    ("Youtube" . (lambda (candidate)
                   (helm-search-suggest-perform-additional-action
                    helm-search-suggest-action-youtube-url
                    candidate)))
    ("IMDb" . (lambda (candidate)
                (helm-search-suggest-perform-additional-action
                 helm-search-suggest-action-imdb-url
                 candidate)))
    ("Google Maps" . (lambda (candidate)
                       (helm-search-suggest-perform-additional-action
                        helm-search-suggest-action-google-maps-url
                        candidate)))
    ("Google News" . (lambda (candidate)
                       (helm-search-suggest-perform-additional-action
                        helm-search-suggest-action-google-news-url
                        candidate))))
  "List of actions for google suggest sources."
  :group 'helm-net
  :type '(alist :key-type string :value-type function))

(defcustom helm-browse-url-firefox-new-window "-new-tab"
  "Allow choosing to browse url in new window or new tab.
Can be \"-new-tab\" (default) or \"-new-window\"."
  :group 'helm-net
  :type '(radio
          (const :tag "New tab" "-new-tab")
          (const :tag "New window" "-new-window")))

(defcustom helm-net-curl-switches '("-s" "-L")
  "Arguments list passed to curl when using `helm-net-prefer-curl'."
  :group 'helm-net
  :type '(repeat string))

;;; Additional actions for search suggestions
;;
;;
;; Internal

(defun helm-search-suggest-perform-additional-action (url query)
  "Perform the search via URL using QUERY as input."
  (browse-url (format url (url-hexify-string query))))

(defun helm-net--url-retrieve-sync (request parser)
  (if helm-net-prefer-curl
      (with-temp-buffer
        (apply #'call-process "curl"
               nil t nil request helm-net-curl-switches)
        (funcall parser))
      (with-current-buffer (url-retrieve-synchronously request)
        (funcall parser))))


;;; Google Suggestions
;;
;;
(defun helm-google-suggest-parser ()
  (cl-loop
   with result-alist = (xml-get-children
                        (car (xml-parse-region
                              (point-min) (point-max)))
                        'CompleteSuggestion)
   for i in result-alist collect
   (cdr (cl-caadr (assq 'suggestion i)))))

(defun helm-google-suggest-fetch (input)
  "Fetch suggestions for INPUT from XML buffer."
  (let ((request (format helm-google-suggest-url
                         (url-hexify-string input))))
    (helm-net--url-retrieve-sync
     request #'helm-google-suggest-parser)))

(defun helm-google-suggest-set-candidates (&optional request-prefix)
  "Set candidates with result and number of google results found."
  (let ((suggestions (helm-google-suggest-fetch
                      (or (and request-prefix
                               (concat request-prefix
                                       " " helm-pattern))
                          helm-pattern))))
    (if (member helm-pattern suggestions)
        suggestions
        ;; if there is no suggestion exactly matching the input then
        ;; prepend a Search on Google item to the list
        (append
         suggestions
         (list (cons (format "Search for '%s' on Google" helm-input)
                     helm-input))))))

(defun helm-ggs-set-number-result (num)
  (if num
      (progn
        (and (numberp num) (setq num (number-to-string num)))
        (cl-loop for i in (reverse (split-string num "" t))
              for count from 1
              append (list i) into C
              when (= count 3)
              append (list ",") into C
              and do (setq count 0)
              finally return
              (replace-regexp-in-string
               "^," "" (mapconcat 'identity (reverse C) ""))))
    "?"))

(defun helm-google-suggest-action (candidate)
  "Default action to jump to a google suggested candidate."
  (let ((arg (format helm-google-suggest-search-url
                     (url-hexify-string candidate))))
    (helm-aif helm-google-suggest-default-browser-function
        (funcall it arg)
      (helm-browse-url arg))))

(defvar helm-google-suggest-default-function
  'helm-google-suggest-set-candidates
  "Default function to use in helm google suggest.")

(defvar helm-source-google-suggest
  (helm-build-sync-source "Google Suggest"
    :candidates (lambda ()
                  (funcall helm-google-suggest-default-function))
    :action 'helm-google-suggest-actions
    :volatile t
    :keymap helm-map
    :requires-pattern 3))

(defun helm-google-suggest-emacs-lisp ()
  "Try to emacs lisp complete with google suggestions."
  (helm-google-suggest-set-candidates "emacs lisp"))


;;; Web browser functions.
;;
;;
;; If default setting of `w3m-command' is not
;; what you want and you modify it, you will have to reeval
;; also `helm-browse-url-default-browser-alist'.

(defvar helm-browse-url-chromium-program "chromium-browser")
(defvar helm-browse-url-uzbl-program "uzbl-browser")
(defvar helm-browse-url-conkeror-program "conkeror")
(defvar helm-browse-url-opera-program "opera")
(defvar helm-browse-url-default-browser-alist
  `((,(or (and (boundp 'w3m-command) w3m-command)
          "/usr/bin/w3m") . w3m-browse-url)
    (,browse-url-firefox-program . browse-url-firefox)
    (,helm-browse-url-chromium-program . helm-browse-url-chromium)
    (,helm-browse-url-conkeror-program . helm-browse-url-conkeror)
    (,helm-browse-url-opera-program . helm-browse-url-opera)
    (,helm-browse-url-uzbl-program . helm-browse-url-uzbl)
    (,browse-url-kde-program . browse-url-kde)
    (,browse-url-gnome-moz-program . browse-url-gnome-moz)
    (,browse-url-mozilla-program . browse-url-mozilla)
    (,browse-url-galeon-program . browse-url-galeon)
    (,browse-url-netscape-program . browse-url-netscape)
    (,browse-url-mosaic-program . browse-url-mosaic)
    (,browse-url-xterm-program . browse-url-text-xterm)
    ("emacs" . eww-browse-url))
  "*Alist of \(executable . function\) to try to find a suitable url browser.")

(cl-defun helm-generic-browser (url cmd-name &rest args)
  "Browse URL with NAME browser."
  (let ((proc (concat cmd-name " " url)))
    (message "Starting %s..." cmd-name)
    (apply 'start-process proc nil cmd-name
           (append args (list url)))
    (set-process-sentinel
     (get-process proc)
     (lambda (process event)
         (when (string= event "finished\n")
           (message "%s process %s" process event))))))

;;;###autoload
(defun helm-browse-url-firefox (url &optional _ignore)
  "Same as `browse-url-firefox' but detach from emacs.

So when you quit emacs you can keep your firefox session open
and not be prompted to kill firefox process.

NOTE: Probably not supported on some systems (e.g Windows)."
  (interactive (list (read-string "URL: " (browse-url-url-at-point))
                     nil))
  (setq url (browse-url-encode-url url))
  (let ((process-environment (browse-url-process-environment)))
    (call-process-shell-command
     (format "(%s %s %s &)"
             browse-url-firefox-program
             helm-browse-url-firefox-new-window
             (shell-quote-argument url)))))

;;;###autoload
(defun helm-browse-url-opera (url &optional _ignore)
  "Browse URL with opera browser and detach from emacs.

So when you quit emacs you can keep your opera session open
and not be prompted to kill opera process.

NOTE: Probably not supported on some systems (e.g Windows)."
  (interactive (list (read-string "URL: " (browse-url-url-at-point))
                     nil))
  (setq url (browse-url-encode-url url))
  (let ((process-environment (browse-url-process-environment)))
    (call-process-shell-command
     (format "(%s %s &)"
             helm-browse-url-opera-program (shell-quote-argument url)))))

;;;###autoload
(defun helm-browse-url-chromium (url &optional _ignore)
  "Browse URL with google chrome browser."
  (interactive "sURL: ")
  (helm-generic-browser
   url helm-browse-url-chromium-program))

;;;###autoload
(defun helm-browse-url-uzbl (url &optional _ignore)
  "Browse URL with uzbl browser."
  (interactive "sURL: ")
  (helm-generic-browser url helm-browse-url-uzbl-program "-u"))

;;;###autoload
(defun helm-browse-url-conkeror (url &optional _ignore)
  "Browse URL with conkeror browser."
  (interactive "sURL: ")
  (helm-generic-browser url helm-browse-url-conkeror-program))

(defun helm-browse-url-default-browser (url &rest args)
  "Find the first available browser and ask it to load URL."
  (let ((default-browser-fn
         (cl-loop for (exe . fn) in helm-browse-url-default-browser-alist
               thereis (and exe (executable-find exe) (fboundp fn) fn))))
    (if default-browser-fn
        (apply default-browser-fn url args)
      (error "No usable browser found"))))

(defun helm-browse-url (url &rest args)
  "Default command to browse URL."
  (if browse-url-browser-function
      (browse-url url args)
    (helm-browse-url-default-browser url args)))


;;; Surfraw
;;
;; Need external program surfraw.
;; <http://surfraw.alioth.debian.org/>

;; Internal
(defvar helm-surfraw-engines-history nil)
(defvar helm-surfraw-input-history nil)
(defvar helm-surfraw--elvi-cache nil)

(defun helm-build-elvi-list ()
  "Return list of all engines and descriptions handled by surfraw."
  (or helm-surfraw--elvi-cache
      (setq helm-surfraw--elvi-cache
            (cdr (with-temp-buffer
                   (call-process "surfraw" nil t nil "-elvi")
                   (split-string (buffer-string) "\n"))))))

;;;###autoload
(defun helm-surfraw (pattern engine)
  "Preconfigured `helm' to search PATTERN with search ENGINE."
  (interactive
   (list
    (let* ((default (if (use-region-p)
                        (buffer-substring-no-properties
                         (region-beginning) (region-end))
                      (thing-at-point 'symbol)))
           (prompt (if default
                       (format "SearchFor (default %s): " default)
                     "SearchFor: ")))
      (read-string prompt nil 'helm-surfraw-input-history default))
    (helm-comp-read
     "Engine: "
     (helm-build-elvi-list)
     :must-match t
     :name "Surfraw Search Engines"
     :del-input nil
     :history helm-surfraw-engines-history)))
  (let* ((engine-nodesc (car (split-string engine)))
         (url (if (string= engine-nodesc "duckduckgo")
                  ;; "sr duckduckgo -p foo" is broken, workaround.
                  (format helm-surfraw-duckduckgo-url
                          (url-hexify-string pattern))
                (with-temp-buffer
                  (apply 'call-process "surfraw" nil t nil
                         (append  (list engine-nodesc "-p") (split-string pattern)))
                  (replace-regexp-in-string
                   "\n" "" (buffer-string)))))
         (browse-url-browser-function (or helm-surfraw-default-browser-function
                                          browse-url-browser-function)))
    (if (string= engine-nodesc "W")
        (helm-browse-url helm-home-url)
      (helm-browse-url url)
      (setq helm-surfraw-engines-history
            (cons engine (delete engine helm-surfraw-engines-history))))))

;;;###autoload
(defun helm-google-suggest ()
  "Preconfigured `helm' for google search with google suggest."
  (interactive)
  (helm-other-buffer 'helm-source-google-suggest "*helm google*"))

(provide 'helm-net)

;; Local Variables:
;; byte-compile-warnings: (not obsolete)
;; coding: utf-8
;; indent-tabs-mode: nil
;; End:

;;; helm-net.el ends here