--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_pubsub_twitter/mod_pubsub_twitter.lua	Wed Apr 03 14:40:03 2013 +0100
@@ -0,0 +1,126 @@
+-- Publishes Twitter search results over pubsub
+--
+-- Config:
+-- Component "pubsub.example.com" "pubsub"
+-- modules_enabled = {
+--   "pubsub_twitter";
+-- }
+-- twitter_searches = { -- node -> query
+--   prosody = "prosody xmpp";
+-- }
+-- twitter_pull_interval = 20 -- minutes
+-- 
+
+local pubsub = module:depends"pubsub";
+
+local json = require "util.json";
+local http = require "net.http";
+local set = require "util.set";
+local it = require "util.iterators";
+local array = require "util.array";
+
+local st = require "util.stanza";
+--local dump = require"util.serialization".serialize;
+
+local xmlns_atom = "http://www.w3.org/2005/Atom";
+
+local twitter_searches = module:get_option("twitter_searches", {});
+local refresh_interval = module:get_option_number("twitter_pull_interval", 20) * 60;
+local api_url = module:get_option_string("twitter_search_url", "http://search.twitter.com/search.json");
+
+local month_number = {
+	Jan = "01", Feb = "02", Mar = "03";
+	Apr = "04", May = "05", Jun = "06";
+	Jul = "07", Aug = "08", Sep = "09";
+	Oct = "10", Nov = "11", Dec = "12";
+};
+
+local active_searches = {};
+
+local function publish_result(search_name, result)
+	local node, id = search_name, result.id_str;
+	--"Tue, 02 Apr 2013 15:40:54 +0000"
+	local timestamp_date, timestamp_month, timestamp_year, timestamp_time = 
+		result.created_at:match(" (%d+) (%a+) (%d+) (%d%d:%d%d:%d%d)");
+	
+	local timestamp = ("%s-%s-%sT%sZ"):format(timestamp_year, month_number[timestamp_month], timestamp_date, timestamp_time);
+	
+	local item = st.stanza("entry", { xmlns = xmlns_atom })
+		:tag("id"):text(id):up()
+		:tag("author")
+			:tag("name"):text(result.from_user_name.." (@"..result.from_user..")"):up()
+			:tag("uri"):text("http://twitter.com/"..result.from_user):up()
+			:up()
+		:tag("published"):text(timestamp):up()
+		:tag("title"):text(result.text):up()
+		:tag("link", { rel = "alternate" , href = "https://twitter.com/"..result.from_user.."/status/"..id}):up();
+	
+	module:log("debug", "Publishing Twitter result: %s", tostring(item));
+	
+	local ok, err = pubsub.service:publish(node, true, id, item);
+	if not ok then
+		if err == "item-not-found" then -- try again
+			local ok, err = pubsub.service:create(node, true);
+			if not ok then
+				module:log("error", "could not create node %s: %s", node, err);
+				return;
+			end
+			local ok, err = pubsub.service:publish(node, true, id, item);
+			if not ok then
+				module:log("error", "could not create or publish node %s: %s", node, err);
+				return
+			end
+		else
+			module:log("error", "publishing %s failed: %s", node, err);
+		end
+	end
+end
+
+local function is_retweet(tweet)
+	return not not tweet.text:match("^RT ");
+end
+
+function update_all()
+	module:log("debug", "Updating all searches");
+	for name, search in pairs(active_searches) do
+		module:log("debug", "Fetching new results for '%s'", name);
+		http.request(search.refresh_url or search.url, nil, function (result_json, code)
+			if code ~= 200 then
+				module:log("warn", "Twitter search query '%s' failed with code %d", name, code);
+				return;
+			end
+			local response = json.decode(result_json);
+			module:log("debug", "Processing %d results for %s", #response.results, name);
+			search.refresh_url = api_url..response.refresh_url;
+			for _, result in ipairs(response.results) do
+				if not is_retweet(result) then
+					publish_result(name, result);
+				end
+			end
+		end);
+	end
+	return refresh_interval;
+end
+
+function module.load()
+	local config_searches = set.new(array.collect(it.keys(twitter_searches)));
+	local current_searches = set.new(array.collect(it.keys(active_searches)));
+	
+	local disable_searches = current_searches - config_searches;
+	local new_searches = config_searches - current_searches;
+	
+	for search_name in disable_searches do
+		module:log("debug", "Disabled old Twitter search '%s'", search_name);
+		active_searches[search_name] = nil;
+	end
+
+	for search_name in new_searches do
+		module:log("debug", "Created new Twitter search '%s'", search_name);
+		local query = twitter_searches[search_name];
+		active_searches[search_name] = {
+			url = api_url.."?q="..http.urlencode(query);
+		};
+	end
+end
+
+module:add_timer(5, update_all);