;;; debbugs-gnu.el --- interface for the GNU bug tracker

;; Copyright (C) 2011 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: comm, hypermedia, maint
;; Package: debbugs
;; Version: 0.1

;; 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 <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(require 'debbugs)
(require 'widget)
(eval-when-compile (require 'cl))

(autoload 'gnus-read-ephemeral-emacs-bug-group "gnus-group")
(autoload 'mail-header-subject "nnheader")
(autoload 'gnus-summary-article-header "gnus-sum")
(autoload 'message-make-from "message")

(defface debbugs-new '((t (:foreground "red")))
  "Face for new reports that nobody has answered.")

(defface debbugs-handled '((t (:foreground "ForestGreen")))
  "Face for new reports that nobody has answered.")

(defface debbugs-stale '((t (:foreground "orange")))
  "Face for new reports that nobody has answered.")

(defface debbugs-done '((t (:foreground "DarkGrey")))
  "Face for closed bug reports.")

(defvar debbugs-widget-map
  (let ((map (make-sparse-keymap)))
    (define-key map "\r" 'widget-button-press)
    map))

(defun debbugs-emacs (severities &optional package suppress-done archivedp)
  "List all outstanding Emacs bugs."
  (interactive
   (list
    (completing-read "Severity: "
		     '("important" "normal" "minor" "wishlist")
		     nil t "normal")))
  (unless (consp severities)
    (setq severities (list severities)))
  (let ((debbugs-port "gnu.org")
	(default 500)
	ids widgets)
    (dolist (severity severities)
      (setq ids (nconc ids
		       (debbugs-get-bugs :package (or package "emacs")
					 :severity severity
					 :archive (if archivedp
						      "1" "0")))))
    (setq ids (sort ids '<))

    (if (> (length ids) default)
	(let ((cursor-in-echo-area nil))
	  (setq default
		(string-to-number
		 (read-string
		  (format
		   "How many reports (available %d, default %d): "
		   (length ids) default)
		  nil
		  nil
		  (number-to-string default))))))

    (if (> (length ids) default)
	(let ((i 0)
	      curr-ids)
	  (while ids
	    (setq i (1+ i)
		  curr-ids (butlast ids (- (length ids) default))
		  widgets (append
			   widgets
			   (list
			    (widget-convert
			     'push-button
			     :follow-link 'mouse-face
			     :notify (lambda (widget &rest ignore)
				       (debbugs-show-reports
					(widget-get widget :suppress-done)
					widget
					(widget-get widget :widgets)))
			     :keymap debbugs-widget-map
			     :suppress-done suppress-done
			     :buffer-name (format "*Emacs Bugs*<%d>" i)
			     :bug-ids (butlast ids (- (length ids) default))
			     (format " %d" i))))
		  ids (last ids (- (length ids) default))))
	  (debbugs-show-reports suppress-done (car widgets) widgets))

      (debbugs-show-reports suppress-done
			    (widget-convert
			     'const
			     :buffer-name "*Emacs Bugs*"
			     :bug-ids ids)
			    nil))))

(defun debbugs-show-reports (suppress-done widget widgets)
  "Show bug reports as given in WIDGET property :bug-ids."
  (pop-to-buffer (get-buffer-create (widget-get widget :buffer-name)))
  (debbugs-mode)
  (let ((inhibit-read-only t))
    (erase-buffer)

    (when widgets
      (widget-insert "Page:")
      (mapc
       (lambda (obj)
	 (widget-insert " ")
	 (widget-put obj :widgets widgets)
	 (if (eq obj widget)
	     (widget-put obj :button-face 'widget-button-pressed)
	   (widget-put obj :button-face 'widget-button-face))
	 (widget-apply obj :create))
       widgets)
      (widget-insert "\n\n"))

    (dolist (status (sort (apply 'debbugs-get-status
				 (widget-get widget :bug-ids))
			  (lambda (s1 s2)
			    (< (cdr (assq 'id s1))
			       (cdr (assq 'id s2))))))
      (when (or (not suppress-done)
		(not (equal (cdr (assq 'pending status)) "done")))
	(let ((address (mail-header-parse-address
			(decode-coding-string (cdr (assq 'originator status))
					      'utf-8)))
	      (subject (decode-coding-string (cdr (assq 'subject status))
					     'utf-8))
	      merged)
	  (setq address
		;; Prefer the name over the address.
		(or (cdr address)
		    (car address)))
	  (insert
	   (format "%5d %-20s [%-23s] %s\n"
		   (cdr (assq 'id status))
		   (let ((words
			  (mapconcat
			   'identity
			   (cons (cdr (assq 'severity status))
				 (cdr (assq 'keywords status)))
			   ",")))
		     (unless (equal (cdr (assq 'pending status)) "pending")
		       (setq words
			     (concat words "," (cdr (assq 'pending status)))))
		     (when (setq merged (cdr (assq 'mergedwith status)))
		       (setq words (format "%s,%s"
					   (if (numberp merged)
					       merged
					     (mapconcat 'number-to-string merged
							","))
					   words)))
		     (if (> (length words) 20)
			 (propertize (substring words 0 20) 'help-echo words)
		       words))
		   (if (> (length address) 23)
		       (propertize (substring address 0 23) 'help-echo address)
		     address)
		   (propertize subject 'help-echo subject)))
	  (forward-line -1)
	  (put-text-property (point) (1+ (point))
			     'debbugs-status status)
	  (put-text-property
	   (+ (point) 5) (+ (point) 26)
	   'face
	   (cond
	    ((equal (cdr (assq 'pending status)) "done")
	     'debbugs-done)
	    ((= (cdr (assq 'date status))
		(cdr (assq 'log_modified status)))
	     'debbugs-new)
	    ((< (- (float-time)
		   (cdr (assq 'log_modified status)))
		(* 60 60 24 4))
	     'debbugs-handled)
	    (t
	     'debbugs-stale)))
	  (forward-line 1))))

    (when widgets
      (widget-insert "\nPage:")
      (mapc
       (lambda (obj)
	 (widget-insert " ")
	 (widget-put obj :widgets widgets)
	 (if (eq obj widget)
	     (widget-put obj :button-face 'widget-button-pressed)
	   (widget-put obj :button-face 'widget-button-face))
	 (widget-apply obj :create))
       widgets)
      (widget-setup))

    (goto-char (point-min))))

(defvar debbugs-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "\r" 'debbugs-select-report)
    (define-key map "q" 'kill-buffer)
    (define-key map "s" 'debbugs-toggle-sort)
    (define-key map "d" 'debbugs-display-status)
    map))

(defvar debbugs-sort-state 'number)

(defun debbugs-mode ()
  "Major mode for listing bug reports.

All normal editing commands are switched off.
\\<debbugs-mode-map>

The following commands are available:

\\{debbugs-mode-map}"
  (interactive)
  (kill-all-local-variables)
  (setq major-mode 'debbugs-mode)
  (setq mode-name "Debbugs")
  (use-local-map debbugs-mode-map)
  (set (make-local-variable 'debbugs-sort-state)
       'number)
  (buffer-disable-undo)
  (setq truncate-lines t)
  (setq buffer-read-only t))

(defvar debbugs-state-preference
  '((debbugs-new . 1)
    (debbugs-stale . 2)
    (debbugs-handled . 3)
    (debbugs-done . 4)))

(defun debbugs-toggle-sort ()
  "Toggle sorting by age and by state."
  (interactive)
  (beginning-of-line)
  (let ((buffer-read-only nil)
	(before-change-functions nil)
	(current-bug (and (not (eobp))
			  (buffer-substring (point) (+ (point) 5)))))
    (setq debbugs-sort-state
	  (if (eq debbugs-sort-state 'number)
	      'state
	    'number))
    (goto-char (point-min))
    (while (and (not (eobp))
		(not (get-text-property (point) 'debbugs-status)))
      (forward-line 1))
    (save-restriction
      (narrow-to-region
       (point)
       (progn
	 (goto-char (point-max))
	 (beginning-of-line)
	 (while (and (not (bobp))
		     (not (get-text-property (point) 'debbugs-status)))
	   (forward-line -1))
	 (forward-line 1)
	 (point)))
      (goto-char (point-min))
      (sort-subr
       nil (lambda () (forward-line 1)) 'end-of-line
       (lambda ()
	 (if (eq debbugs-sort-state 'number)
	     (string-to-number (buffer-substring (point) (+ (point) 5)))
	   (or (cdr (assq (get-text-property (+ (point) 7) 'face)
			  debbugs-state-preference))
	       10)))))
    (if (not current-bug)
	(goto-char (point-max))
      (goto-char (point-min))
      (re-search-forward (concat "^" current-bug) nil t))))

(defvar debbugs-bug-number nil)

(defun debbugs-current-id ()
  (or (cdr (assq 'id (get-text-property (line-beginning-position)
					'debbugs-status)))
      (error "No bug on the current line")))

(defun debbugs-display-status (id)
  "Display the status of the report on the current line."
  (interactive (list (debbugs-current-id)))
  (let ((status (get-text-property (line-beginning-position)
				   'debbugs-status)))
    (pop-to-buffer "*Bug Status*")
    (erase-buffer)
    (pp status (current-buffer))
    (goto-char (point-min))))

(defun debbugs-select-report (id)
  "Select the report on the current line."
  (interactive (list (debbugs-current-id)))
  ;; We open the report messages.
  (gnus-read-ephemeral-emacs-bug-group
   id (cons (current-buffer)
	    (current-window-configuration)))
  (with-current-buffer (window-buffer (selected-window))
    (debbugs-summary-mode 1)
    (set (make-local-variable 'debbugs-bug-number) id)))))

(defvar debbugs-summary-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "C" 'debbugs-send-control-message)
    map))

(define-minor-mode debbugs-summary-mode
  "Minor mode for providing a debbugs interface in Gnus summary buffers.

\\{debbugs-summary-mode-map}"
  :lighter " Debbugs" :keymap debbugs-summary-mode-map
  (set (make-local-variable 'gnus-posting-styles)
       '((".*"
	  (eval
	   (with-current-buffer gnus-article-copy
	     (set (make-local-variable 'message-prune-recipient-rules)
		  '((".*@debbugs.*" "emacs-pretest-bug")
		    (".*@debbugs.*" "bug-gnu-emacs")))
	     (set (make-local-variable 'message-alter-recipients-function)
		  (lambda (address)
		    (if (string-match "\\([0-9]+\\)@donarmstrong" (car address))
			(let ((new (format "%s@debbugs.gnu.org"
					   (match-string 1 (car address)))))
			  (cons new new))
		      address)))))))))

(defun debbugs-send-control-message (message)
  "Send a control message for the current bug report.
You can set the severity or add a tag, or close the report.  If
you use the special \"done\" MESSAGE, the report will be marked as
fixed, and then closed."
  (interactive
   (list (completing-read
	  "Control message: "
	  '("important" "normal" "minor" "wishlist"
	    "done"
	    "unarchive" "reopen" "close"
	    "merge" "forcemerge"
	    "patch" "wontfix" "moreinfo" "unreproducible" "fixed" "notabug")
	  nil t)))
  (let* ((id debbugs-bug-number)	; Set on group entry.
	 (version
	  (when (member message '("close" "done"))
	    (read-string
	     "Version: "
	     (cond
	      ;; Emacs development versions.
	      ((string-match
		"^\\([0-9]+\\)\\.\\([0-9]+\\)\\.\\([0-9]+\\)\\." emacs-version)
	       (format "%s.%d"
		       (match-string 1 emacs-version)
		       (1+ (string-to-number (match-string 2 emacs-version)))))
	      ;; Emacs release versions.
	      ((string-match
		"^\\([0-9]+\\)\\.\\([0-9]+\\)\\.\\([0-9]+\\)$" emacs-version)
	       (format "%s.%s"
		       (match-string 1 emacs-version)
		       (match-string 2 emacs-version)))
	      (t emacs-version))))))
    (with-temp-buffer
      (insert "To: control@debbugs.gnu.org\n"
	      "From: " (message-make-from) "\n"
	      (format "Subject: control message for bug #%d\n" id)
	      "\n"
	      (cond
	       ((member message '("unarchive" "reopen"))
		(format "%s %d\n" message id))
	       ((member message '("merge" "forcemerge"))
		(format "%s %d %s\n" message id
			(read-string "Merge with bug #: ")))
	       ((equal message "close")
		(format "close %d %s\n" id version))
	       ((equal message "done")
		(format "tags %d fixed\nclose %d %s\n" id id version))
	       ((member message '("important" "normal" "minor" "wishlist"))
		(format "severity %d %s\n" id message))
	       (t
		(format "tags %d %s\n" id message))))
      (funcall send-mail-function))))

(provide 'debbugs-gnu)

;;; TODO:

;; * Widget-oriented bug overview like webDDTs.
;; * Actions on bugs.
;; * Integration into gnus (nnir).

;;; debbugs-gnu.el ends here