-- Allow Slack-style incoming and outgoing hooks to MUC rooms

-- Based on mod_muc_intercom and mod_post_msg

-- Copyright 2016-2017 Nathan Whitehorn <nwhitehorn@physics.ucla.edu>

--

-- This file is MIT/X11 licensed.

module:depends"http"

local msg = require "util.stanza".message;

local jid = require "util.jid";

local now = require "util.datetime".datetime;

local json = require "util.json"

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

local http = require "net.http";

local mod_muc = module:depends"muc";

local rooms = rawget(mod_muc, "rooms");

local get_room_from_jid = rawget(mod_muc, "get_room_from_jid") or

	function (room_jid)

		return rooms[room_jid];

	end

local routing = module:get_option("outgoing_webhook_routing") or {};

local listen_path = module:get_option("incoming_webhook_path") or "/webhook";

local default_from_nick = module:get_option("incoming_webhook_default_nick") or "Bot";

function postcallback(_, code)

	module:log("debug", "HTTP result %d", code)

end

function check_message(data)

	local stanza = data.stanza;

	local this_room = get_room_from_jid(stanza.attr.to);

	if not this_room then return; end -- no such room

	local from_room_jid = this_room._jid_nick[stanza.attr.from];

	if not from_room_jid then return; end -- no such nick

	local from_room, from_host, from_nick = jid.split(from_room_jid);

	local body = stanza:get_child("body");

	if not body then return; end -- No body, like topic changes

	body = body and body:get_text(); -- I feel like I want to do `or ""` there :/

	if not routing[from_room] then

		return;

	end

	local json_out = {

		channel_name = from_room,

		timestamp = now(),

		text = body,

		team_domain = from_host,

		user_name = from_nick,

	};

	local stanzaid = stanza:get_child("id");

	if stanzaid and string.sub(stanzaid,1,string.len("webhookbot"))=="webhookbot" then

		json_out["bot_id"] = "webhookbot";

	end

	json_out = json.encode(json_out)

	local url = routing[from_room];

	module:log("debug", "message from %s in %s to %s", from_nick, from_room, url);

	if url == "DEBUG" then

		module:log("debug", "json_out = %s", json_out);

		return;

	end

	local headers = {

		["Content-Type"] = "application/json",

	};

	http.request(url, { method = "POST", body = json_out, headers = headers }, postcallback)

end

module:hook("message/bare", check_message, 10);

local function route_post(f)

	return function(event, path)

		local bare_room = jid.join(path, module.host);

		if not get_room_from_jid(bare_room) then

			module:log("warn", "mod_slack_webhook: invalid JID: %s", bare_room);

			return 404;

		end

		-- Check secret?

		return f(event, path)

	end

end

local function handle_post(event, path)

	local request = event.request;

	local headers = request.headers;

	local body_type = headers.content_type;

	local post_body;

	if body_type == "application/x-www-form-urlencoded" then

		post_body = formdecode(request.body);

	elseif body_type == "application/json" then

		post_body = json.decode(request.body)

		if not post_body then

			return 420;

		end

	else

		return 422;

	end

	local bare_room = jid.join(path, module.host);

	local dest_room = get_room_from_jid(bare_room);

	local from_nick = default_from_nick;

	if post_body["username"] then

		from_nick = post_body["username"];

	end

	local sender = jid.join(path, module.host, from_nick);

	module:log("debug", "message to %s from %s", bare_room, sender);

	module:log("debug", "body: %s", post_body["text"]);

	local message = msg({ to = bare_room, from = sender, type = "groupchat", id="webhookbot" .. now()},post_body["text"]);

	dest_room:broadcast_message(message, true);

	return 201;

end

module:provides("http", {

	default_path = listen_path;

	route = {

		["POST /*"] = route_post(handle_post);

		OPTIONS = function(e)

			local headers = e.response.headers;

			headers.allow = "POST";

			headers.accept = "application/x-www-form-urlencoded, application/json";

			return 200;

		end;

	}

});