local full_sessions = full_sessions;

local bare_sessions = bare_sessions;

local st = require "util.stanza";

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

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

local user_exists = require "core.usermanager".user_exists;

local urlencode = require "net.http".urlencode;

local add_task = require "util.timer".add_task;

local os_time = os.time;

local t_concat = table.concat;

local smtp = require "socket.smtp";

local smtp_server = module:get_option("smtp_server");

local smtp_user = module:get_option("smtp_username");

local smtp_pass = module:get_option("smtp_password");

local smtp_address = module:get_option("smtp_from") or ((smtp_user or "xmpp").."@"..(smtp_server or module.host));

local queue_offline_emails = module:get_option("queue_offline_emails");

if queue_offline_emails == true then queue_offline_emails = 300; end

local send_message_as_email;

local message_body_from_stanza;

function process_to_bare(bare, origin, stanza)

	local user = bare_sessions[bare];

	local t = stanza.attr.type;

	if t == nil or t == "chat" or t == "normal" then -- chat or normal message

		if not (user and user.top_resources) then -- No resources online?

			if user_exists(jid_split(bare)) then

				local text = message_body_from_stanza(stanza);

				if text then

					send_message_as_email(bare, jid_bare(stanza.attr.from), text);

				else

					module:log("error", "Unable to extract message body from offline message to put into an email");

				end

			end

		end

	end

	return; -- Leave for further processing

end

module:hook("message/full", function(data)

	-- message to full JID recieved

	local origin, stanza = data.origin, data.stanza;

	local session = full_sessions[stanza.attr.to];

	if not session then -- resource not online

		return process_to_bare(jid_bare(stanza.attr.to), origin, stanza);

	end

end, 20);

module:hook("message/bare", function(data)

	-- message to bare JID recieved

	local origin, stanza = data.origin, data.stanza;

	return process_to_bare(stanza.attr.to or (origin.username..'@'..origin.host), origin, stanza);

end, 20);

function send_message_as_email(address, from_address, message_text, subject)

		module:log("info", "Forwarding offline message to %s via email", address);

		local rcpt = "<"..address..">";

		local from_user, from_domain = jid_split(from_address);

		local from = "<"..urlencode(from_user).."@"..from_domain..">";

		local mesgt = {

			headers = {

				to = address;

				subject = subject or ("Offline message from "..jid_bare(from_address));

			};

			body = message_text;

		};

	local ok, err = smtp.send{ from = from, rcpt = rcpt, source = smtp.message(mesgt), 

		server = smtp_server, user = smtp_user, password = smtp_pass };

	if not ok then

		module:log("error", "Failed to deliver to %s: %s", tostring(address), tostring(err));

		return false;

	end

	return true;

end

if queue_offline_emails then

	local queues = {};

	local real_send_message_as_email = send_message_as_email;

	function send_message_as_email(address, from_address, message_text)

		local pair_key = address.."\0"..from_address;

		local queue = queues[pair_key];

		if not queue then

			queue = { from = from_address, to = address, messages = {} };

			queues[pair_key] = queue;

			add_task(queue_offline_emails+5, function () 

				module:log("info", "Checking on %s", from_address);

				local current_time = os_time();

				local diff = current_time - queue.last_message_time;

				if diff > queue_offline_emails then

					module:log("info", "Enough silence, sending...");

					real_send_message_as_email(address, from_address, t_concat(queue.messages, "\n"), "You have "..#queue.messages.." offline message"..(#queue.messages == 1 and "" or "s").." from "..from_address)

				else

					module:log("info", "Next check in %d", queue_offline_emails - diff + 5);

					return queue_offline_emails - diff + 5;

				end

			end);

		end

		queue.last_message_time = os_time();

		local messages = queue.messages;

		messages[#messages+1] = message_text;

	end

end

function message_body_from_stanza(stanza)

	local message_text = stanza:child_with_name("body");

	if message_text then

		return message_text:get_text();

	end

end