--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_sms_free/mod_sms_free.lua	Sun Oct 06 17:29:22 2019 +0200
@@ -0,0 +1,125 @@
+local http = require "net.http";
+local jid_split = require "util.jid".split;
+local dataforms_new = require "util.dataforms".new;
+local adhoc_new = module:require "adhoc".new;
+local adhoc_simple_form = require "util.adhoc".new_simple_form;
+local t_concat = table.concat;
+
+local store = module:open_store();
+
+local function api_handler(body, code)
+	if code == 200 then
+		module:log("debug", "SMS correctly sent.");
+	elseif code == 0 then
+		module:log("error", "error querying Free API: %s", body);
+	elseif code >= 400 then
+		module:log("warn", "received error code %d: %s", code, body);
+	end
+end
+
+local function message_handler(event)
+	local message = event.stanza;
+	local username, host = jid_split(message.attr.to);
+
+	-- Only proceed if the user has set Free credentials.
+	local data = store:get(username);
+	if not data then
+		return;
+	end
+
+	-- Only proceed if the message is of type chat or normal.
+	local message_type = message.attr.type;
+	if message_type == "error" or message_type == "headline" or message_type == "groupchat" then
+		-- TODO: Maybe handle groupchat or headline in the future.
+		return;
+	end
+
+	-- Only proceed if the message contains a body.
+	local body = message:get_child_text("body");
+	if not body then
+		return;
+	end
+
+	-- Only proceed if all sessions are "xa", or if there are no sessions.
+	local sessions = prosody.hosts[host].sessions[username];
+	if sessions then
+		local do_send = true;
+		for _, session in pairs(sessions.sessions) do
+			local show = session.presence:get_child_text("show");
+			if show ~= "xa" then
+				do_send = false;
+			end
+		end
+		if not do_send then
+			return;
+		end
+	end
+
+	-- Then do the actual request to send the SMS.
+	local headers = {
+		user = data.user,
+		pass = data.pass,
+		msg = http.urlencode(body),
+	};
+	http.request("https://smsapi.free-mobile.fr/sendmsg", { headers = headers }, api_handler);
+end
+
+local set_form = dataforms_new {
+	title = "Set mobile.free.fr SMS credentials";
+	instructions = "Enable the “Notifications by SMS” service at https://mobile.free.fr/moncompte/ and paste the credentials in this form.";
+	{
+		type = "hidden";
+		name = "FORM_TYPE";
+		value = "http://prosody.im/protocol/sms_free#set";
+	};
+	{
+		type = "text-single";
+		name = "user";
+		label = "Your login on Free’s website";
+	};
+	{
+		type = "text-single";
+		name = "pass";
+		label = "Your authentication key";
+	};
+};
+
+local set_adhoc = adhoc_simple_form(set_form, function (data, errors, state)
+	if errors then
+		local errmsg = {};
+		for name, text in pairs(errors) do
+			errmsg[#errmsg + 1] = name .. ": " .. text;
+		end
+		return { status = "completed", error = { message = t_concat(errmsg, "\n") } };
+	end
+
+	local username, host = jid_split(state.from);
+	module:log("debug", "Setting mobile.free.fr credentials for %s@%s: user=%s, pass=%s", username, host, data.user, data.pass);
+	local ok, err = store:set(username, { user = data.user, pass = data.pass });
+	if ok then
+		return { status = "completed", info = "SMS notifications to your phone enabled." };
+	else
+		return { status = "completed", error = { message = err } };
+	end
+end);
+
+module:provides("adhoc", adhoc_new("Set mobile.free.fr SMS notification credentials", "http://prosody.im/protocol/sms_free#set", set_adhoc));
+
+module:provides("adhoc", adhoc_new("Unset mobile.free.fr SMS notifications", "http://prosody.im/protocol/sms_free#unset", function (_, data)
+	if data.action ~= "execute" then
+		return { status = "canceled" };
+	end
+
+	module:log("debug", "Unsetting mobile.free.fr credentials.");
+	local username, host = jid_split(data.from);
+	local ok, err = store:set(username, nil);
+	if ok then
+		return { status = "completed", info = "SMS notifications to your phone disabled." };
+	else
+		return { status = "completed", error = { message = err } };
+	end
+end));
+
+-- Stanzas sent to local clients.
+module:hook("message/bare", message_handler);
+module:hook("message/full", message_handler);