From f6536078d32ed6dbacfb70fc96423b30bee21ec4 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Sat, 20 Sep 2014 13:00:23 -0700
Subject: [PATCH] nmbug.js: Extract the Gmane article id and convert to a
 Message-ID

Using some JavaScript gymnastics to look through the available frames
for an article.gmane.org/ URL.  For example, we might be on a page
like:

  http://thread.gmane.org/gmane.mail.notmuch.general/19055/focus=19056

which is composed of the following frames [1]:

  http://news.gmane.org/group/gmane.mail.notmuch.general/thread=19055/force_load=t/focus=19056
  http://article.gmane.org/gmane.mail.notmuch.general/19056
  http://news.gmane.org/navbar.php?group=gmane.mail.notmuch.general&article=19056&next=19057&prev=19054&newsrc=,19056

Or we might be on the article page directly.  There are also permalink
pages (with 'permalink' instead of 'article' available from the
blog-link view), but I'm not worrying about them yet.

[1]: for (var i = 0; i < window.frames.length; i++) {
       console.log(window.frames[i].document.URL);
     }
---
 nmbug.js | 40 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/nmbug.js b/nmbug.js
index 214c9f2..5a8a141 100644
--- a/nmbug.js
+++ b/nmbug.js
@@ -1,3 +1,5 @@
+var nmbug_server = 'http://localhost:5000';
+
 nmbug = {
 	show: function (message_id) {
 		alert(message_id);
@@ -7,7 +9,43 @@ nmbug = {
 var _gmane_handler = {
 	regexp: /gmane[.]org/,
 	handle: function (callback) {
-		throw 'Extract the Message-ID from ' + document.URL;
+		var article = this._get_article();
+		this._get_message_id(article, callback);
+	},
+	_article_from_url: function (url) {
+		var regexp = new RegExp('http://article.gmane.org/([^/]+)/([0-9]+)');
+		var match = regexp.exec(url);
+		console.log('nmbug: get article from ' + url, match);
+		if (match) {
+			return {'group': match[1], 'id': parseInt(match[2])};
+		}
+	},
+	_get_article: function () {
+		var article = this._article_from_url(document.URL);
+		var i = 0;
+		for (var i = 0; !article && i < window.frames.length; i++) {
+			article = this._article_from_url(window.frames[i].document.URL);
+		}
+		if (!article) {
+			throw "Cannot extract an article from Gmane's " + document.URL;
+		}
+		return article;
+	},
+	_get_message_id: function (article, callback) {
+		var url = [
+			nmbug_server,
+			'gmane',
+			article.group,
+			article.id,
+		].join('/');
+		console.log('nmbug: get Message-ID from ' + url);
+		var request = new XMLHttpRequest();
+		request.onload = function () {
+			var message_id = this.responseText;
+			callback(message_id);
+		};
+		request.open('get', url, true);
+		request.send();
 	},
 };
 
-- 
2.26.2