local mod_muc = module:depends("muc")

local http = require "net.http"

local st = require "util.stanza"

local json = require "util.json"

local url_pattern = [[https://twitter.com/%S+/status/%S+]]

local xmlns_fasten = "urn:xmpp:fasten:0"

local xmlns_xhtml = "http://www.w3.org/1999/xhtml"

local twitter_apiv2_bearer_token = module:get_option_string("twitter_apiv2_bearer_token");

local function fetch_tweet_data(room, url, tweet_id, origin_id)

	if not url then return; end

	local options = {

		method = "GET";

		headers = { Authorization = "Bearer "..twitter_apiv2_bearer_token; };

	};

	http.request(

		'https://api.twitter.com/2/tweets/'..tweet_id..'?expansions=author_id&tweet.fields=created_at,text&user.fields=id,name,username,profile_image_url',

		options,

		function(response_body, response_code, _)

			if response_code ~= 200 then

				module:log("debug", "Call to %s returned code %s and body %s", url, response_code, response_body)

				return;

			end

			local response = json.decode(response_body);

			if not response then return; end

			if not response['data'] or not response['includes'] then return; end

			local tweet = response['data'];

			local author = response['includes']['users'][1];

			local to = room.jid

			local from = room and room.jid or module.host

			local fastening = st.message({to = to, from = from, type = 'groupchat'}):tag("apply-to", {xmlns = xmlns_fasten, id = origin_id})

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:article:author',

					content = author['username']

				}

			):up()

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:article:published_time',

					content = tweet['created_at']

				}

			):up()

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:description',

					content = tweet['text']

				}

			):up()

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:image',

					content = author['profile_image_url']

				}

			):up()

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:title',

					content = author['username']

				}

			):up()

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:type',

					content = 'tweet'

				}

			):up()

			fastening:tag(

				"meta",

				{

					xmlns = xmlns_xhtml,

					property = 'og:url',

					content = 'https://twitter.com/'..author['username']..'/status/'..tweet['id']

				}

			):up()

			mod_muc.get_room_from_jid(room.jid):broadcast_message(fastening)

			module:log("debug", tostring(fastening))

		end

	)

end

local function tweet_handler(event)

	local room, stanza = event.room, st.clone(event.stanza)

	local body = stanza:get_child_text("body")

	if not body then return; end

	local origin_id = stanza:find("{urn:xmpp:sid:0}origin-id@id")

	if not origin_id then return; end

	for url in body:gmatch(url_pattern) do

		local _, _, _, tweet_id = string.find(url, "https://twitter.com/(%S+)/status/(%S+)");

		fetch_tweet_data(room, url, tweet_id, origin_id);

	end

end

module:hook("muc-occupant-groupchat", tweet_handler)

module:hook("muc-message-is-historic", function (event)

	local fastening = event.stanza:get_child('apply-to', xmlns_fasten)

	if fastening and fastening:get_child('meta', xmlns_xhtml) then

		return true

	end

end);