local jid_prep = require "util.jid".prep;

local secure_auth = module:get_option_boolean("s2s_secure_auth", false);

local secure_domains, insecure_domains =

	module:get_option_set("s2s_secure_domains", {})._items, module:get_option_set("s2s_insecure_domains", {})._items;

local untrusted_fail_watchers = module:get_option_set("untrusted_fail_watchers", module:get_option("admins", {})) / jid_prep;

local untrusted_fail_notification = module:get_option("untrusted_fail_notification", "Establishing a secure connection from $from_host to $to_host failed. Certificate hash: $sha1. $errors");

local st = require "util.stanza";

module:hook_global("s2s-check-certificate", function (event)

    local session, host = event.session, event.host;

    local conn = session.conn:socket();

    local local_host = session.direction == "outgoing" and session.from_host or session.to_host;

    if not (local_host == module:get_host()) then return end

    module:log("debug", "Checking certificate...");

    local must_secure = secure_auth;

    if not must_secure and secure_domains[host] then

            must_secure = true;

    elseif must_secure and insecure_domains[host] then

            must_secure = false;

    end

    if must_secure and (session.cert_chain_status ~= "valid" or session.cert_identity_status ~= "valid") then

		local _, errors = conn:getpeerverification();

		local error_message = "";

		for depth, t in pairs(errors or {}) do

			if #t > 0 then

				error_message = error_message .. "Error with certificate " .. (depth - 1) .. ": " .. table.concat(t, ", ") .. ". ";

			end

		end

		if session.cert_identity_status then

			error_message = error_message .. "This certificate is " .. session.cert_identity_status .. " for " .. host .. ".";

		end

		local replacements = { sha1 = event.cert and event.cert:digest("sha1"), errors = error_message };

		local message = st.message{ type = "chat", from = local_host }

			:tag("body")

				:text(untrusted_fail_notification:gsub("%$([%w_]+)", function (v)

					return event[v] or session and session[v] or replacements and replacements[v] or nil;

				end));

		for jid in untrusted_fail_watchers do

			module:log("debug", "Notifying %s", jid);

			message.attr.to = jid;

			module:send(message);

		end

	end

end, -0.5);