local dt = require "util.datetime";

local jid = require "util.jid";

local st = require "util.stanza";

local url = require "socket.url";

local new_id = require "util.id".short;

local render = require"util.interpolation".new("%b{}", function (s) return s; end);

local destinations = module:get_option_set("spam_report_destinations", {});

local archive = module:open("archive");

local cache_size = module:get_option_number("spam_report_forwarder_contact_cache_size", 256);

local report_to_origin = module:get_option_boolean("spam_report_forwarder_to_origin", true);

local contact_lookup_timeout = module:get_option_number("spam_report_forwarder_contact_lookup_timeout", 180);

local body_template = module:get_option_string("spam_report_forwarder_body_template", [[

SPAM/ABUSE REPORT

-----------------

Reported JID: {reported_jid}

A user on our service has reported a message originating from the above JID on

your server.

{reported_message_time&The reported message was sent at: {reported_message_time}}

--

This message contains also machine-readable payloads, including XEP-0377, in case

you want to automate handling of these reports. You can receive these reports

to a different address by setting 'spam-report-addresses' in your server

contact info configuration. For more information, see https://xmppbl.org/reports/

]]):gsub("^%s+", ""):gsub("(%S)\n(%S)", "%1 %2");

local report_addresses = require "util.cache".new(cache_size);

local function get_address(form, ...)

	for i = 1, select("#", ...) do

		local field_var = select(i, ...);

		local field = form:get_child_with_attr("field", "jabber:x:data", "var", field_var);

		if field then

			local parsed = url.parse(field:get_child_text("value"));

			if parsed.scheme == "xmpp" and parsed.path and not parsed.query then

				return parsed.path;

			end

		end

	end

end

local function get_origin_report_address(reported_jid)

	local host = jid.host(reported_jid);

	local address = report_addresses:get(host);

	if address then return address; end

	local contact_query = st.iq({ to = host, from = module.host, id = new_id() })

		:query("http://jabber.org/protocol/disco#info");

	return module:send_iq(contact_query, prosody.hosts[module.host], contact_lookup_timeout)

		:next(function (response)

			if response.attr.type ~= "result" then return; end

			for form in response.tags[1]:childtags("x", "jabber:x:data") do

				local form_type = form:get_child_with_attr("field", nil, "var", "FORM_TYPE");

				if form_type == "http://jabber.org/network/serverinfo" then

					address = get_address(form, "spam-report-addresses", "abuse-addresses");

					break;

				end

			end

			return address;

		end);

end

local function send_report(to, message)

	local m = st.clone(message);

	m.attr.to = to;

	module:send(m);

end

function forward_report(event)

	local reporter_username = event.origin.username;

	local reporter_jid = jid.join(reporter_username, module.host);

	local reported_jid = event.jid;

	local report = st.clone(event.report);

	report:text_tag("jid", reported_jid, { xmlns = "urn:xmpp:jid:0" });

	local reported_message_id = report:get_child_with_attr(

		"stanza-id",

		"urn:xmpp:sid:0",

		"by",

		reported_jid,

		jid.prep

	);

	local reported_message, reported_message_time, reported_message_with;

	if reported_message_id then

		reported_message, reported_message_time, reported_message_with = archive:get(reporter_username, reported_message_id);

		if jid.bare(reported_message_with) ~= event.jid then

			reported_message = nil;

		end

	end

	local body_text = render(body_template, {

		reporter_jid = reporter_jid;

		reported_jid = event.jid;

		reported_message_time = dt.datetime(reported_message_time);

	});

	local message = st.message({ from = module.host })

		:text_tag("body", body_text)

		:add_child(report);

	if reported_message then

		reported_message.attr.xmlns = "jabber:client";

		local fwd = st.stanza("forwarded", { xmlns = "urn:xmpp:forward:0" })

			:tag("delay", { xmlns = "urn:xmpp:delay", stamp = dt.datetime(reported_message_time) }):up()

			:add_child(reported_message);

		message:add_child(fwd);

	end

	for destination in destinations do

		send_report(destination, message);

	end

	if report_to_origin then

		module:log("debug", "Sending report to origin server...");

		get_origin_report_address(event.jid):next(function (origin_report_address)

			if not origin_report_address then

				module:log("warn", "Couldn't report to origin: no contact address found for %s", jid.host(event.jid));

				return;

			end

			send_report(origin_report_address, message);

		end);

	end

end

module:hook("spam_reporting/abuse-report", forward_report, -1);

module:hook("spam_reporting/spam-report", forward_report, -1);

module:hook("spam_reporting/unknown-report", forward_report, -1);