local log = require "util.logger".init("modulemanager")

local loadfile, pcall = loadfile, pcall;

local setmetatable, setfenv, getfenv = setmetatable, setfenv, getfenv;

local pairs, ipairs = pairs, ipairs;

local t_insert = table.insert;

local type = type;

local tostring, print = tostring, print;

local _G = _G;

local debug = debug;

module "modulemanager"

local handler_info = {};

local handlers = {};

local modulehelpers = setmetatable({}, { __index = _G });

local function _add_iq_handler(module, origin_type, xmlns, handler)

	handlers[origin_type] = handlers[origin_type] or {};

	handlers[origin_type].iq = handlers[origin_type].iq or {};

	if not handlers[origin_type].iq[xmlns] then

		handlers[origin_type].iq[xmlns]= handler;

		handler_info[handler] = module;

		log("debug", "mod_%s now handles tag 'iq' with query namespace '%s'", module.name, xmlns);

	else

		log("warning", "mod_%s wants to handle tag 'iq' with query namespace '%s' but mod_%s already handles that", module.name, xmlns, handler_info[handlers[origin_type].iq[xmlns]].module.name);

	end

end

function modulehelpers.add_iq_handler(origin_type, xmlns, handler)

	if not (origin_type and handler and xmlns) then return false; end

	if type(origin_type) == "table" then

		for _, origin_type in ipairs(origin_type) do

			_add_iq_handler(getfenv(2).module, origin_type, xmlns, handler);

		end

		return;

	end

	_add_iq_handler(getfenv(2).module, origin_type, xmlns, handler);

end

local function _add_handler(module, origin_type, tag, xmlns, handler)

	handlers[origin_type] = handlers[origin_type] or {};

	if not handlers[origin_type][tag] then

		handlers[origin_type][tag] = handlers[origin_type][tag] or {};

		handlers[origin_type][tag][xmlns]= handler;

		handler_info[handler] = module;

		log("debug", "mod_%s now handles tag '%s'", module.name, tag);

	elseif handler_info[handlers[origin_type][tag]] then

		log("warning", "mod_%s wants to handle tag '%s' but mod_%s already handles that", module.name, tag, handler_info[handlers[origin_type][tag]].module.name);

	end

end

function modulehelpers.add_handler(origin_type, tag, xmlns, handler)

	if not (origin_type and tag and xmlns and handler) then return false; end

	if type(origin_type) == "table" then

		for _, origin_type in ipairs(origin_type) do

			_add_handler(getfenv(2).module, origin_type, tag, xmlns, handler);

		end

		return;

	end

	_add_handler(getfenv(2).module, origin_type, tag, xmlns, handler);

end

function load(name)

	local mod, err = loadfile("plugins/mod_"..name..".lua");

	if not mod then

		log("error", "Unable to load module '%s': %s", name or "nil", err or "nil");

		return nil, err;

	end

	local pluginenv = setmetatable({ module = { name = name } }, { __index = modulehelpers });

	setfenv(mod, pluginenv);

	local success, ret = pcall(mod);

	if not success then

		log("error", "Error initialising module '%s': %s", name or "nil", ret or "nil");

		return nil, ret;

	end

	return true;

end

function handle_stanza(origin, stanza)

	local name, xmlns, origin_type = stanza.name, stanza.attr.xmlns, origin.type;

	if name == "iq" and xmlns == "jabber:client" and handlers[origin_type] then

		log("debug", "Stanza is an <iq/>");

		local child = stanza.tags[1];

		if child then

			local xmlns = child.attr.xmlns or xmlns;

			log("debug", "Stanza of type %s from %s has xmlns: %s", name, origin_type, xmlns);

			local handler = handlers[origin_type][name] and handlers[origin_type][name][xmlns];

			if handler then

				log("debug", "Passing stanza to mod_%s", handler_info[handler].name);

				return handler(origin, stanza) or true;

			end

		end

	elseif handlers[origin_type] then

		local handler = handlers[origin_type][name];

		if  handler then

			handler = handler[xmlns];

			if handler then

				log("debug", "Passing stanza to mod_%s", handler_info[handler].name);

				return handler(origin, stanza) or true;

			end

		end

	end

	log("debug", "Stanza unhandled by any modules, xmlns: %s", stanza.attr.xmlns);

	return false; -- we didn't handle it

end

do

	local event_handlers = {};

	function modulehelpers.add_event_hook(name, handler)

		if not event_handlers[name] then

			event_handlers[name] = {};

		end

		t_insert(event_handlers[name] , handler);

	end

	function fire_event(name, ...)

		local event_handlers = event_handlers[name];

		if event_handlers then

			for name, handler in ipairs(event_handlers) do

				handler(...);

			end

		end

	end

end

return _M;