module:depends("http");

local st = require "util.stanza";

local json = require "util.json";

local hmac_sha1 = require "util.hashes".hmac_sha1;

local pubsub_service = module:depends("pubsub").service;

local default_node = module:get_option("github_node", "github");

local node_prefix = module:get_option_string("github_node_prefix", "github/");

local node_mapping = module:get_option_string("github_node_mapping");

local github_actor = module:get_option_string("github_actor") or true;

local secret = module:get_option("github_secret");

assert(secret, "Please set 'github_secret'");

local error_mapping = {

	["forbidden"] = 403;

	["item-not-found"] = 404;

	["internal-server-error"] = 500;

	["conflict"] = 409;

};

function handle_POST(event)

	local request, response = event.request, event.response;

	if ("sha1=" .. hmac_sha1(secret, request.body, true)) ~= request.headers.x_hub_signature then

		return 401;

	end

	local data = json.decode(request.body);

	if not data then

		response.status_code = 400;

		return "Invalid JSON. From you of all people...";

	end

	local github_event = request.headers.x_github_event

	if github_event == "push" then

		module:log("debug", "Handling 'push' event: \n%s\n", tostring(request.body));

	elseif github_event then

		module:log("debug", "Unsupported Github event %q", github_event);

		return 501;

	end -- else .. is this even github?

	local node = default_node;

	if node_mapping then

		node = node_prefix .. data.repository[node_mapping];

	end

	for _, commit in ipairs(data.commits) do

		local ok, err = pubsub_service:publish(node, github_actor, commit.id,

			st.stanza("item", { id = commit.id, xmlns = "http://jabber.org/protocol/pubsub" })

			:tag("entry", { xmlns = "http://www.w3.org/2005/Atom" })

				:tag("id"):text(commit.id):up()

				:tag("link", { rel = "alternate", href = commit.url }):up()

				:tag("published"):text(commit.author.date):up()

				:tag("author")

					:tag("name"):text(commit.author.name):up()

					:tag("email"):text(commit.author.email):up()

					:up()

		);

		if not ok then

			return error_mapping[err] or 500;

		end

	end

	response.status_code = 202;

	return "Thank you Github!";

end

module:provides("http", {

	route = {

		POST = handle_POST;

	};

});

if not node_mapping then

	function module.load()

		if not pubsub_service.nodes[default_node] then

			local ok, err = pubsub_service:create(default_node, true);

			if not ok then

				module:log("error", "Error creating node: %s", err);

			else

				module:log("debug", "Node %q created", default_node);

			end

		end

	end

end