local multitable = require "util.multitable";

local fire_event = prosody.events.fire_event;

--- Config

local default_interfaces = { "*" };

local default_local_interfaces = { "127.0.0.1" };

if config.get("*", "use_ipv6") then

	table.insert(default_interfaces, "::");

	table.insert(default_local_interfaces, "::1");

end

--- Private state

-- service_name -> { service_info, ... }

local services = setmetatable({}, { __index = function (t, k) rawset(t, k, {}); return rawget(t, k); end });

-- service_name, interface (string), port (number)

local active_services = multitable.new();

--- Private helpers

local function error_to_friendly_message(service_name, port, err)

	local friendly_message = err;

	if err:match(" in use") then

		-- FIXME: Use service_name here

		if port == 5222 or port == 5223 or port == 5269 then

			friendly_message = "check that Prosody or another XMPP server is "

				.."not already running and using this port";

		elseif port == 80 or port == 81 then

			friendly_message = "check that a HTTP server is not already using "

				.."this port";

		elseif port == 5280 then

			friendly_message = "check that Prosody or a BOSH connection manager "

				.."is not already running";

		else

			friendly_message = "this port is in use by another application";

		end

	elseif err:match("permission") then

		friendly_message = "Prosody does not have sufficient privileges to use this port";

	elseif err == "no ssl context" then

		if not config.get("*", "core", "ssl") then

			friendly_message = "there is no 'ssl' config under Host \"*\" which is "

				.."require for legacy SSL ports";

		else

			friendly_message = "initializing SSL support failed, see previous log entries";

		end

	end

	return friendly_message;

end

module("portmanager", package.seeall);

prosody.events.add_handler("item-added/net-provider", function (event)

	local item = event.item;

	register_service(item.name, item);

end);

prosody.events.add_handler("item-removed/net-provider", function (event)

	local item = event.item;

	unregister_service(item.name, item);

end);

--- Public API

function activate_service(service_name)

	local service_info = services[service_name][1];

	if not service_info then

		return nil, "Unknown service: "..service_name;

	end

	local listener = service_info.listener;

	local config_prefix = (service_info.config_prefix or service_name).."_";

	if config_prefix == "_" then

		config_prefix = "";

	end

	local bind_interfaces = set.new(config.get("*", config_prefix.."interfaces")

		or config.get("*", config_prefix.."interface") -- COMPAT w/pre-0.9

		or (service_info.private and default_local_interfaces)

		or config.get("*", "interfaces")

		or config.get("*", "interface") -- COMPAT w/pre-0.9

		or listener.default_interface -- COMPAT w/pre0.9

		or default_interfaces);

	local bind_ports = set.new(config.get("*", config_prefix.."ports")

		or service_info.default_ports

		or {listener.default_port}); -- COMPAT w/pre-0.9

	local mode = listener.default_mode or "*a";

	local ssl;

	if service_info.encryption == "ssl" then

		ssl = prosody.global_ssl_ctx;

		if not ssl then

			return nil, "global-ssl-context-required";

		end

	end

	for interface in bind_interfaces do

		for port in bind_ports do

				log("error", "Multiple services configured to listen on the same port ([%s]:%d): %s, %s", interface, port, active_services:search(nil, interface, port)[1][1].service.name or "<unnamed>", service_name or "<unnamed>");

			else

				local handler, err = server.addserver(interface, port, listener, mode, ssl);

				if not handler then

					log("error", "Failed to open server port %d on %s, %s", port, interface, error_to_friendly_message(service_name, port, err));

				else

					log("debug", "Added listening service %s to [%s]:%d", service_name, interface, port);

					active_services:add(service_name, interface, port, {

						server = handler;

						service = service_info;

					});

				end

			end

		end

	end

	log("info", "Activated service '%s'", service_name);

	return true;

end

function deactivate(service_name)

	local active = active_services:search(service_name)[1];

	if not active then return; end

	for interface, ports in pairs(active) do

		for port, active_service in pairs(ports) do

			active_service:close();

			active_services:remove(service_name, interface, port, active_service);

			log("debug", "Removed listening service %s from [%s]:%d", service_name, interface, port);

		end

	end

	log("info", "Deactivated service '%s'", service_name);

end

function register_service(service_name, service_info)

	table.insert(services[service_name], service_info);

	if not active_services:get(service_name) then

		log("debug", "No active service for %s, activating...", service_name);

		local ok, err = activate_service(service_name);

		if not ok then

			log("error", "Failed to activate service '%s': %s", service_name, err or "unknown error");

		end

	end

	fire_event("service-added", { name = service_name, service = service_info });

	return true;

end

function unregister_service(service_name, service_info)

	local service_info_list = services[service_name];

	for i, service in ipairs(service_info_list) do

		if service == service_info then

			table.remove(service_info_list, i);

		end

	end

	if active_services[service_name] == service_info then

		deactivate(service_name);

		if #service_info_list > 0 then -- Other services registered with this name

			activate(service_name); -- Re-activate with the next available one

		end

	end

	fire_event("service-removed", { name = service_name, service = service_info });

end

function get_service(service_name)

	return services[service_name];

end

function get_active_services(...)

	return active_services;

end

return _M;