-- XEP-0280: Message Carbons implementation for Prosody

-- Copyright (C) 2011 Kim Alvefur

--

-- This file is MIT/X11 licensed.

local st = require "util.stanza";

local jid_bare = require "util.jid".bare;

local jid_split = require "util.jid".split;

local xmlns_carbons = "urn:xmpp:carbons:1";

local xmlns_forward = "urn:xmpp:forward:0";

local host_sessions = hosts[module.host].sessions;

module:hook("iq/self/"..xmlns_carbons..":enable", function(event)

	local origin, stanza = event.origin, event.stanza;

	if stanza.attr.type == "set" then

		module:log("debug", "%s enabled carbons", origin.full_jid);

		origin.want_carbons = true;

		origin.send(st.reply(stanza));

		return true

	end

end);

module:hook("iq/self/"..xmlns_carbons..":disable", function(event)

	local origin, stanza = event.origin, event.stanza;

	if stanza.attr.type == "set" then

		module:log("debug", "%s disabled carbons", origin.full_jid);

		origin.want_carbons = nil;

		origin.send(st.reply(stanza));

		return true

	end

end);

local function message_handler(event, c2s)

	local origin, stanza = event.origin, event.stanza;

	local orig_type = stanza.attr.type;

	local orig_to = stanza.attr.to;

	local orig_from = stanza.attr.from;

	if not (orig_type == nil

			or orig_type == "normal"

			or orig_type == "chat") then

		return -- No carbons for messages of type error or headline

	end

	local bare_jid, user_sessions;

	local no_carbon_to = {};

	module:log("debug", "Message from %s to %s", tostring(orig_from), tostring(orig_to));

	if c2s then -- Stanza sent by a local client

		bare_jid = (origin.username.."@"..origin.host)

		user_sessions = host_sessions[origin.username];

	else -- Stanza about to be delivered to a local client

		local username, hostname, resource = jid_split(orig_to);

		bare_jid = jid_bare(orig_to);

		user_sessions = host_sessions[username];

		if resource then

			module:log("debug", "Message was to resource %s, it will not get carbon", resource);

			no_carbon_to[resource] = true;

		elseif user_sessions then

			local top_resources = user_sessions.top_resources;

			if top_resources then

				for _, session in ipairs(top_resources) do

					module:log("debug", "Not sending carbons to top resource %s", session.resource);

					no_carbon_to[session.resource] = true;

				end

			end

		end

	end

	if not user_sessions then

		module:log("debug", "Skip carbons for offline user");

		return -- No use in sending carbons to an offline user

	end

	if not c2s and stanza:get_child("private", xmlns_carbons) then

		stanza:maptags(function(tag)

			return tag.attr.xmlns == xmlns_carbons

				and tag.name == "private" and tag or nil;

		end);

		module:log("debug", "Message tagged private, ignoring");

		return

	end

			end

		end

	end

end

local function c2s_message_handler(event)

	return message_handler(event, true)

end

-- Stanzas sent by local clients

module:hook("pre-message/bare", c2s_message_handler, 1);

module:hook("pre-message/full", c2s_message_handler, 1);

-- Stanzas to local clients

module:hook("message/bare", message_handler, 1);

module:hook("message/full", message_handler, 1);

module:add_feature(xmlns_carbons);