;;; package-x.el --- Package extras  -*- lexical-binding: t; -*-

;; Copyright (C) 2007-2022 Free Software Foundation, Inc.

;; Author: Tom Tromey <tromey@redhat.com>
;; Created: 10 Mar 2007
;; Keywords: tools
;; Package: package

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; This file currently contains parts of the package system that many
;; won't need, such as package uploading.

;; To upload to an archive, first set `package-archive-upload-base' to
;; some desired directory.  For testing purposes, you can specify any
;; directory you want, but if you want the archive to be accessible to
;; others via http, this is typically a directory in the /var/www tree
;; (possibly one on a remote machine, accessed via Tramp).

;; Then call M-x package-upload-file, which prompts for a file to
;; upload.  Alternatively, M-x package-upload-buffer uploads the
;; current buffer, if it's visiting a package file.

;; Once a package is uploaded, users can access it via the Package
;; Menu, by adding the archive to `package-archives'.

;;; Code:

(require 'package)
(defvar gnus-article-buffer)

(defcustom package-archive-upload-base "/path/to/archive"
  "The base location of the archive to which packages are uploaded.
The commands in the package-x library will use this as base
location.
This should be an absolute directory name.  If the archive is on
another machine, you may specify a remote name in the usual way,
e.g. \"/ssh:foo@example.com:/var/www/packages/\".
See Info node `(emacs)Remote Files'.

Unlike `package-archives', you can't specify a HTTP URL."
  :type 'directory
  :group 'package
  :version "24.1")

(defvar package-update-news-on-upload nil
  "Whether uploading a package should also update NEWS and RSS feeds.")

(defun package--encode (string)
  "Encode a string by replacing some characters with XML entities."
  ;; We need a special case for translating "&" to "&amp;".
  (let ((index))
    (while (setq index (string-match "[&]" string index))
      (setq string (replace-match "&amp;" t nil string))
      (setq index (1+ index))))
  (while (string-match "[<]" string)
    (setq string (replace-match "&lt;" t nil string)))
  (while (string-match "[>]" string)
    (setq string (replace-match "&gt;" t nil string)))
  (while (string-match "[']" string)
    (setq string (replace-match "&apos;" t nil string)))
  (while (string-match "[\"]" string)
    (setq string (replace-match "&quot;" t nil string)))
  string)

(defun package--make-rss-entry (title text archive-url)
  (let ((date-string (format-time-string "%a, %d %B %Y %T %z")))
    (concat "<item>\n"
	    "<title>" (package--encode title) "</title>\n"
	    ;; FIXME: should have a link in the web page.
	    "<link>" archive-url "news.html</link>\n"
	    "<description>" (package--encode text) "</description>\n"
	    "<pubDate>" date-string "</pubDate>\n"
	    "</item>\n")))

(defun package--make-html-entry (title text)
  (concat "<li> " (format-time-string "%B %e") " - "
	  title " - " (package--encode text)
	  " </li>\n"))

(defun package--update-file (file tag text)
  "Update the package archive file named FILE.
FILE should be relative to `package-archive-upload-base'.
TAG is a string that can be found within the file; TEXT is
inserted after its first occurrence in the file."
  (setq file (expand-file-name file package-archive-upload-base))
  (save-excursion
    (let ((old-buffer (find-buffer-visiting file)))
      (with-current-buffer (let ((find-file-visit-truename t))
			     (or old-buffer (find-file-noselect file)))
	(goto-char (point-min))
	(search-forward tag)
	(forward-line)
	(insert text)
	(let ((file-precious-flag t))
	  (save-buffer))
	(unless old-buffer
	  (kill-buffer (current-buffer)))))))

(defun package--archive-contents-from-url (archive-url)
  "Parse archive-contents file at ARCHIVE-URL.
Return the file contents, as a string, or nil if unsuccessful."
  (when archive-url
    (with-temp-buffer
      (ignore-errors
	(url-insert-file-contents (concat archive-url "archive-contents"))
	(package-read-from-string
	 (buffer-substring-no-properties (point-min) (point-max)))))))

(defun package--archive-contents-from-file ()
  "Parse the archive-contents at `package-archive-upload-base'."
  (let ((file (expand-file-name "archive-contents"
				package-archive-upload-base)))
    (if (not (file-exists-p file))
	;; No existing archive-contents means a new archive.
	(list package-archive-version)
      (let ((dont-kill (find-buffer-visiting file)))
	(with-current-buffer (let ((find-file-visit-truename t))
			       (find-file-noselect file))
	  (prog1
	      (package-read-from-string
	       (buffer-substring-no-properties (point-min) (point-max)))
	    (unless dont-kill
	      (kill-buffer (current-buffer)))))))))

(defun package-maint-add-news-item (title description archive-url)
  "Add a news item to the webpages associated with the package archive.
TITLE is the title of the news item.
DESCRIPTION is the text of the news item."
  (interactive "sTitle: \nsText: ")
  (package--update-file "elpa.rss"
			"<description>"
			(package--make-rss-entry title description archive-url))
  (package--update-file "news.html"
			"New entries go here"
			(package--make-html-entry title description)))

(defun package--update-news (package version description archive-url)
  "Update the ELPA web pages when a package is uploaded."
  (package-maint-add-news-item (concat package " version " version)
			       description
			       archive-url))

(declare-function lm-commentary "lisp-mnt" (&optional file))
(defvar tar-data-buffer)

(defun package-upload-buffer-internal (pkg-desc extension &optional archive-url)
  "Upload a package whose contents are in the current buffer.
PKG-DESC is the `package-desc'.
EXTENSION is the file extension, a string.  It can be either
\"el\" or \"tar\".

The upload destination is given by `package-archive-upload-base'.
If its value is invalid, prompt for a directory.

Optional arg ARCHIVE-URL is the URL of the destination archive.
If it is non-nil, compute the new \"archive-contents\" file
starting from the existing \"archive-contents\" at that URL.  In
addition, if `package-update-news-on-upload' is non-nil, call
`package--update-news' to add a news item at that URL.

If ARCHIVE-URL is nil, compute the new \"archive-contents\" file
from the \"archive-contents\" at `package-archive-upload-base',
if it exists."
  (let ((package-archive-upload-base package-archive-upload-base))
    ;; Check if `package-archive-upload-base' is valid.
    (when (or (not (stringp package-archive-upload-base))
	      (equal package-archive-upload-base
		     (custom--standard-value 'package-archive-upload-base)))
      (setq package-archive-upload-base
	    (read-directory-name
	     "Base directory for package archive: ")))
    (unless (file-directory-p package-archive-upload-base)
      (if (y-or-n-p (format "%s does not exist; create it? "
			    package-archive-upload-base))
	  (make-directory package-archive-upload-base t)
	(error "Aborted")))
    (save-excursion
      (save-restriction
	(let* ((file-type (package-desc-kind pkg-desc))
	       (pkg-name (package-desc-name pkg-desc))
	       (requires (package-desc-reqs pkg-desc))
	       (desc (if (eq (package-desc-summary pkg-desc)
                             package--default-summary)
			 (read-string "Description of package: ")
		       (package-desc-summary pkg-desc)))
	       (split-version (package-desc-version pkg-desc))
	       (commentary
                (pcase file-type
                  ('single (lm-commentary))
                  ('tar nil))) ;; FIXME: Get it from the README file.
               (extras (package-desc-extras pkg-desc))
	       (pkg-version (package-version-join split-version))
	       (pkg-buffer (current-buffer)))

          ;; `package-upload-file' will error if given a directory,
          ;; but we check it here as well just in case.
          (when (eq 'dir file-type)
            (user-error "Can't upload directory, tar it instead"))
	  ;; Get archive-contents from ARCHIVE-URL if it's non-nil, or
	  ;; from `package-archive-upload-base' otherwise.
	  (let ((contents (or (package--archive-contents-from-url archive-url)
			      (package--archive-contents-from-file)))
		(new-desc (package-make-ac-desc
                           split-version requires desc file-type extras)))
	    (if (> (car contents) package-archive-version)
		(error "Unrecognized archive version %d" (car contents)))
	    (let ((elt (assq pkg-name (cdr contents))))
	      (if elt
		  (if (version-list-<= split-version
				       (package--ac-desc-version (cdr elt)))
		      (error "New package has smaller version: %s" pkg-version)
		    (setcdr elt new-desc))
		(setq contents (cons (car contents)
				     (cons (cons pkg-name new-desc)
					   (cdr contents))))))

	    ;; Now CONTENTS is the updated archive contents.  Upload
	    ;; this and the package itself.  For now we assume ELPA is
	    ;; writable via file primitives.
	    (let ((print-level nil)
                  (print-quoted t)
		  (print-length nil))
	      (write-region (concat (pp-to-string contents) "\n")
			    nil
			    (expand-file-name "archive-contents"
					      package-archive-upload-base)))

	    ;; If there is a commentary section, write it.
	    (when commentary
	      (write-region commentary nil
	        	    (expand-file-name
	        	     (concat (symbol-name pkg-name) "-readme.txt")
	        	     package-archive-upload-base)))

	    (set-buffer (if (eq file-type 'tar) tar-data-buffer pkg-buffer))
	    (write-region (point-min) (point-max)
			  (expand-file-name
			   (format "%s-%s.%s" pkg-name pkg-version extension)
			   package-archive-upload-base)
			  nil nil nil 'excl)

	    ;; Write a news entry.
	    (and package-update-news-on-upload
		 archive-url
		 (package--update-news (format "%s.%s" pkg-name extension)
				       pkg-version desc archive-url))

	    ;; special-case "package": write a second copy so that the
	    ;; installer can easily find the latest version.
	    (if (eq pkg-name 'package)
		(write-region (point-min) (point-max)
			      (expand-file-name
			       (format "%s.%s" pkg-name extension)
			       package-archive-upload-base)
			      nil nil nil 'ask))))))))

(defun package-upload-buffer ()
  "Upload the current buffer as a single-file Emacs Lisp package.
If `package-archive-upload-base' does not specify a valid upload
destination, prompt for one.
Signal an error if the current buffer is not visiting a simple
package (a \".el\" file)."
  (interactive)
  (save-excursion
    (save-restriction
      ;; Find the package in this buffer.
      (let ((pkg-desc (package-buffer-info)))
	(package-upload-buffer-internal pkg-desc "el")))))

;;;###autoload
(defun package-upload-file (file)
  "Upload the Emacs Lisp package FILE to the package archive.
Interactively, prompt for FILE.  The package is considered a
single-file package if FILE ends in \".el\", and a multi-file
package if FILE ends in \".tar\".
Automatically extract package attributes and update the archive's
contents list with this information.
If `package-archive-upload-base' does not specify a valid upload
destination, prompt for one.  If the directory does not exist, it
is created.  The directory need not have any initial contents
\(i.e., you can use this command to populate an initially empty
archive)."
  (interactive "fPackage file name: ")
  (with-temp-buffer
    (insert-file-contents file)
    (let ((pkg-desc
           (cond
            ((string-match "\\.tar\\'" file)
             (tar-mode) (package-tar-file-info))
            ((string-match "\\.el\\'" file) (package-buffer-info))
            (t (error "Unrecognized extension `%s'"
                      (file-name-extension file))))))
      (package-upload-buffer-internal pkg-desc (file-name-extension file)))))

(defun package-gnus-summary-upload ()
  "Upload a package contained in the current *Article* buffer.
This should be invoked from the gnus *Summary* buffer."
  (interactive)
  (with-current-buffer gnus-article-buffer
    (package-upload-buffer)))

(provide 'package-x)

;;; package-x.el ends here