;; This file:
;;   http://anggtwu.net/elisp/find-wget-jan-2024.el.html
;;   http://anggtwu.net/elisp/find-wget-jan-2024.el
;;          (find-angg "elisp/find-wget-jan-2024.el")
;; Author: Eduardo Ochs <[email protected]>
;; See: https://lists.gnu.org/archive/html/help-gnu-emacs/2024-01/msg00033.html
;;      https://lists.gnu.org/archive/html/help-gnu-emacs/2024-01/threads.html#00033
;; Version: 2024jan14
;; License: GPL3.

;; This is a simplified version of the `find-wget' from eev:
;;
;;   http://anggtwu.net/eev-current/eev-plinks.el.html#find-wget
;;                       (find-eev "eev-plinks.el" "find-wget")
;;
;; Most functions were copied from the source code of eev without
;; changes; only the ones that are marked as "dummified" were replaced
;; by trivial versions.

(defvar ee-wget-program "wget")
(defvar ee-find-callprocess00-exit-status nil)

;; Dummified versions
(defun ee-expand (fname) fname)
(defun ee-goto-rest (list) ())
(defun ee-goto-position (&optional pos-spec &rest rest) ())

(defun find-ebuffer (buffer &rest pos-spec-list)
  "Hyperlink to an Emacs buffer (existing or not)."
  (interactive "bBuffer: ")
  (switch-to-buffer buffer)
  (apply 'ee-goto-position pos-spec-list))

(defun ee-split (str)
  "If STR is a string, split it on whitespace and return the resulting list.
If STR if a list, return it unchanged."
  (if (stringp str)
      (split-string str "[ \t\n]+")
    str))

(defun find-callprocess00-ne (program-and-args)
  (let ((argv (ee-split program-and-args)))
    (with-output-to-string
      (with-current-buffer standard-output
	(setq ee-find-callprocess00-exit-status
	      (apply 'call-process (car argv) nil t nil (cdr argv)))))))

(defun find-wget (url &rest pos-spec-list)
  "Download URL with \"wget -q -O - URL\" and display the output.
If a buffer named \"*wget: URL*\" already exists then this
function visits it instead of running wget again.
If wget can't download URL then this function runs `error'."
  (let* ((eurl (ee-expand url))
	 (wgetprogandargs (list ee-wget-program "-q" "-O" "-" eurl))
	 (wgetbufname (format "*wget: %s*" eurl)))
    (if (get-buffer wgetbufname)
	(apply 'find-ebuffer wgetbufname pos-spec-list)
      ;;
      ;; If the buffer wgetbufname doesn't exist, then:
      (let* ((wgetoutput (find-callprocess00-ne wgetprogandargs))
	     (wgetstatus ee-find-callprocess00-exit-status))
	;;
	(if (not (equal wgetstatus 0))
	    ;; See: (find-node "(wget)Exit Status")
	    (error "wget can't download: %s" eurl))
	;;
	(find-ebuffer wgetbufname)	; create buffer
	(insert wgetoutput)
	(goto-char (point-min))
	(apply 'ee-goto-position pos-spec-list)))))


;; Test: (eval-buffer)
;;       (find-wget "http://anggtwu.net/LUA/Dang1.lua")
;;
;; When we run the test above on Debian the double angle brackets in
;; the line 12 of Dang1.lua are displayed correctly as single
;; characters - and when we run `M-x hexlify-buffer' we see that they
;; take are encoded in two bytes each - c2ab and c2bb. From
;; /usr/share/unicode/UnicodeData.txt:
;;
;; 00AB;LEFT-POINTING DOUBLE ANGLE QUOTATION MARK;Pi;0;ON;;;;;Y;LEFT POINTING GUILLEMET;;;;
;; 00BB;RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK;Pf;0;ON;;;;;Y;RIGHT POINTING GUILLEMET;;;;
;;
;; When we run the `find-wget' above in Emacs 29 for Windows the
;; resulting buffer is put in the encoding "iso-latin-1-dos". `M-x
;; hexlify-buffer' shows that they are still two bytes each - c2ab and
;; c2bb - but they are displayed as two characters each, preceded by
;; "c2"s::
;;
;; 00C2;LATIN CAPITAL LETTER A WITH CIRCUMFLEX;Lu;0;L;0041 0302;;;;N;LATIN CAPITAL LETTER A CIRCUMFLEX;;;00E2;
;;
;; The wget that I am using on Windows was extracted from this zip:
;;
;;   https://eternallybored.org/misc/wget/releases/wget-1.21.2-win64.zip







;; Local Variables:
;; coding:  utf-8-unix
;; End: