-- Prosody IM v0.1

-- Copyright (C) 2008 Matthew Wild

-- Copyright (C) 2008 Waqas Hussain

-- 

-- This program is free software; you can redistribute it and/or

-- modify it under the terms of the GNU General Public License

-- as published by the Free Software Foundation; either version 2

-- of the License, or (at your option) any later version.

-- 

-- This program is distributed in the hope that it will be useful,

-- but WITHOUT ANY WARRANTY; without even the implied warranty of

-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-- GNU General Public License for more details.

-- 

-- You should have received a copy of the GNU General Public License

-- along with this program; if not, write to the Free Software

-- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

--

local plugin_dir = CFG_PLUGINDIR or "./plugins/";

local logger = require "util.logger";

local log = logger.init("modulemanager");

local addDiscoInfoHandler = require "core.discomanager".addDiscoInfoHandler;

local eventmanager = require "core.eventmanager";

local config = require "core.configmanager";

local multitable_new = require "util.multitable".new;

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;

-- We need this to let modules access the real global namespace

local _G = _G;

module "modulemanager"

local api = {}; -- Module API container

local modulemap = {};

local handler_info = {};

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

-- Load modules when a host is activated

function load_modules_for_host(host)

	local modules_enabled = config.get(host, "core", "modules_enabled");

	if modules_enabled then

		for _, module in pairs(modules_enabled) do

			load(host, module);

		end

	end

end

eventmanager.add_event_hook("host-activated", load_modules_for_host);

--

function load(host, module_name, config)

	if not (host and module_name) then

		return nil, "insufficient-parameters";

	end

	local mod, err = loadfile(plugin_dir.."mod_"..module_name..".lua");

	if not mod then

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

		return nil, err;

	end

	if not modulemap[host] then

		modulemap[host] = {};

	elseif modulemap[host][module_name] then

		log("warn", "%s is already loaded for %s, so not loading again", module_name, host);

		return nil, "module-already-loaded";

	end

	local _log = logger.init(host..":"..module_name);

	local api_instance = setmetatable({ name = module_name, host = host, config = config,  _log = _log, log = function (self, ...) return _log(...); end }, { __index = api });

	local pluginenv = setmetatable({ module = api_instance }, { __index = _G });

	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

	modulemap[host][module_name] = mod;

	return true;

end

function is_loaded(host, name)

	return modulemap[host] and modulemap[host][name] and true;

end

function unload(host, name, ...)

	local mod = modulemap[host] and modulemap[host][name];

	if not mod then return nil, "module-not-loaded"; end

	if type(mod.unload) == "function" then

		local ok, err = pcall(mod.unload, ...)

		if (not ok) and err then

			log("warn", "Non-fatal error unloading module '%s' from '%s': %s", name, host, err);

		end

	end

end

function handle_stanza(host, origin, stanza)

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

	if name == "iq" and xmlns == "jabber:client" then

		xmlns = stanza.tags[1].attr.xmlns;

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

	end

	if handlers then

		log("debug", "Passing stanza to mod_%s", handler_info[handlers[1]].name);

		(handlers[1])(origin, stanza);

		return true;

	else

		log("debug", "Stanza unhandled by any modules, xmlns: %s", stanza.attr.xmlns); -- we didn't handle it

	end

end

----- API functions exposed to modules -----------

-- Must all be in api.* 

-- Returns the name of the current module

function api:get_name()

	return self.name;

end

-- Returns the host that the current module is serving

function api:get_host()

	return self.host;

end

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

	local msg = (tag == "iq") and "namespace" or "payload namespace";

	if not handlers then

		handler_info[handler] = module;

		module:log("debug", "I now handle tag '%s' [%s] with %s '%s'", tag, origin_type, msg, xmlns);

	else

		module:log("warn", "I wanted to handle tag '%s' [%s] with %s '%s' but mod_%s already handles that", tag, origin_type, msg, xmlns, handler_info[handlers[1]].module.name);

	end

end

function api: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(self, origin_type, tag, xmlns, handler);

		end

	else

		_add_handler(self, origin_type, tag, xmlns, handler);

	end

end

function api:add_iq_handler(origin_type, xmlns, handler)

	self:add_handler(origin_type, "iq", xmlns, handler);

end

function api:add_feature(xmlns)

	addDiscoInfoHandler(self.host, function(reply, to, from, node)

		if #node == 0 then

			reply:tag("feature", {var = xmlns}):up();

			return true;

		end

	end);

end

function api:add_event_hook (...) return eventmanager.add_event_hook(...); end

--------------------------------------------------------------------

return _M;