-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- 

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

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

local logger = require "util.logger";

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

local config = require "core.configmanager";

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

local st = require "util.stanza";

local pluginloader = require "util.pluginloader";

local hosts = hosts;

local prosody = prosody;

local prosody_events = prosody.events;

local loadfile, pcall, xpcall = loadfile, pcall, xpcall;

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

local pairs, ipairs = pairs, ipairs;

local t_insert, t_concat = table.insert, table.concat;

local type = type;

local next = next;

local rawget = rawget;

local error = error;

local tostring, tonumber = tostring, tonumber;

local debug_traceback = debug.traceback;

local unpack, select = unpack, select;

pcall = function(f, ...)

	local n = select("#", ...);

	local params = {...};

	return xpcall(function() f(unpack(params, 1, n)) end, function(e) return tostring(e).."\n"..debug_traceback(); end);

end

local array, set = require "util.array", require "util.set";

local autoload_modules = {"presence", "message", "iq"};

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

local _G = _G;

module "modulemanager"

api = {};

local api = api; -- Module API container

local modulemap = { ["*"] = {} };

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

local hooks = multitable_new();

local NULL = {};

-- Load modules when a host is activated

function load_modules_for_host(host)

	local disabled_set = {};

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

	if modules_disabled then

		for _, module in ipairs(modules_disabled) do

			disabled_set[module] = true;

		end

	end

	-- Load auto-loaded modules for this host

	if hosts[host].type == "local" then

		for _, module in ipairs(autoload_modules) do

			if not disabled_set[module] then

				load(host, module);

			end

		end

	end

	-- Load modules from global section

	if config.get(host, "core", "load_global_modules") ~= false then

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

		if modules_enabled then

			for _, module in ipairs(modules_enabled) do

				if not disabled_set[module] and not is_loaded(host, module) then

					load(host, module);

				end

			end

		end

	end

	-- Load modules from just this host

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

	if modules_enabled and modules_enabled ~= config.get("*", "core", "modules_enabled") then

		for _, module in pairs(modules_enabled) do

			if not is_loaded(host, module) then

				load(host, module);

			end

		end

	end

end

prosody_events.add_handler("host-activated", load_modules_for_host);

prosody_events.add_handler("component-activated", load_modules_for_host);

--

function load(host, module_name, config)

	if not (host and module_name) then

		return nil, "insufficient-parameters";

	end

	if not modulemap[host] then

		modulemap[host] = {};

	end

	if 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";

	elseif modulemap["*"][module_name] then

		return nil, "global-module-already-loaded";

	end

	local mod, err = pluginloader.load_code(module_name);

	if not mod then

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

		return nil, err;

	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 });

	api_instance.environment = pluginenv;

	setfenv(mod, pluginenv);

	if not hosts[host] then

		local create_component = _G.require "core.componentmanager".create_component;

		hosts[host] = create_component(host);

		hosts[host].connected = false;

		log("debug", "Created new component: %s", host);

	end

	hosts[host].modules = modulemap[host];

	modulemap[host][module_name] = pluginenv;

	local success, err = pcall(mod);

	if success then

		if module_has_method(pluginenv, "load") then

			success, err = call_module_method(pluginenv, "load");

			if not success then

				log("warn", "Error loading module '%s' on '%s': %s", module_name, host, err or "nil");

			end

		end

		-- Use modified host, if the module set one

		if api_instance.host == "*" and host ~= "*" then

			modulemap[host][module_name] = nil;

			modulemap["*"][module_name] = pluginenv;

			api_instance:set_global();

		end

	else

		log("error", "Error initializing module '%s' on '%s': %s", module_name, host, err or "nil");

	end

	if success then

		(hosts[api_instance.host] or prosody).events.fire_event("module-loaded", { module = module_name, host = host });

		return true;

	else -- load failed, unloading

		unload(api_instance.host, module_name);

		return nil, err;

	end

end

function get_module(host, name)

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

end

function is_loaded(host, name)

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

end

function unload(host, name, ...)

	local mod = get_module(host, name);

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

	if module_has_method(mod, "unload") then

		local ok, err = call_module_method(mod, "unload");

		if (not ok) and err then

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

		end

	end

	-- unhook event handlers hooked by module:hook

	for event, handlers in pairs(hooks:get(host, name) or NULL) do

		for handler in pairs(handlers or NULL) do

			(hosts[host] or prosody).events.remove_handler(event, handler);

		end

	end

	hooks:remove(host, name);

	if mod.module.items then -- remove items

		for key,t in pairs(mod.module.items) do

			for i = #t,1,-1 do

				local value = t[i];

				t[i] = nil;

				hosts[host].events.fire_event("item-removed/"..key, {source = self, item = value});

			end

		end

	end

	modulemap[host][name] = nil;

	(hosts[host] or prosody).events.fire_event("module-unloaded", { module = name, host = host });

	return true;

end

function reload(host, name, ...)

	local mod = get_module(host, name);

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

	local _mod, err = pluginloader.load_code(name); -- checking for syntax errors

	if not _mod then

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

		return nil, err;

	end

	local saved;

	if module_has_method(mod, "save") then

		local ok, ret, err = call_module_method(mod, "save");

		if ok then

			saved = ret;

		else

			log("warn", "Error saving module '%s:%s' state: %s", host, module, ret);

			if not config.get(host, "core", "force_module_reload") then

				log("warn", "Aborting reload due to error, set force_module_reload to ignore this");

				return nil, "save-state-failed";

			else

				log("warn", "Continuing with reload (using the force)");

			end

		end

	end

	unload(host, name, ...);

	local ok, err = load(host, name, ...);

	if ok then

		mod = get_module(host, name);

		if module_has_method(mod, "restore") then

			local ok, err = call_module_method(mod, "restore", saved or {})

			if (not ok) and err then

				log("warn", "Error restoring module '%s' from '%s': %s", name, host, err);

			end

		end

		return true;

	end

	return ok, err;

end

function module_has_method(module, method)

	return type(module.module[method]) == "function";

end

function call_module_method(module, method, ...)

	if module_has_method(module, method) then

		local f = module.module[method];

		return pcall(f, ...);

	else

		return false, "no-such-method";

	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

function api:get_host_type()

	return hosts[self.host].type;

end

function api:set_global()

	self.host = "*";

	-- Update the logger

	local _log = logger.init("mod_"..self.name);

	self.log = function (self, ...) return _log(...); end;

	self._log = _log;

end

function api:add_feature(xmlns)

	self:add_item("feature", xmlns);

end

function api:add_identity(category, type, name)

	self:add_item("identity", {category = category, type = type, name = name});

end

function api:fire_event(...)

	return (hosts[self.host] or prosody).events.fire_event(...);

end

function api:hook(event, handler, priority)

	hooks:set(self.host, self.name, event, handler, true);

	(hosts[self.host] or prosody).events.add_handler(event, handler, priority);

end

function api:hook_stanza(xmlns, name, handler, priority)

	if not handler and type(name) == "function" then

		-- If only 2 options then they specified no xmlns

		xmlns, name, handler, priority = nil, xmlns, name, handler;

	elseif not (handler and name) then

		self:log("warn", "Error: Insufficient parameters to module:hook_stanza()");

		return;

	end

	return api.hook(self, "stanza/"..(xmlns and (xmlns..":") or "")..name, function (data) return handler(data.origin, data.stanza, data); end, priority);

end

function api:require(lib)

	local f, n = pluginloader.load_code(self.name, lib..".lib.lua");

	if not f then

		f, n = pluginloader.load_code(lib, lib..".lib.lua");

	end

	if not f then error("Failed to load plugin library '"..lib.."', error: "..n); end -- FIXME better error message

	setfenv(f, self.environment);

	return f();

end

function api:get_option(name, default_value)

	local value = config.get(self.host, self.name, name);

	if value == nil then

		value = config.get(self.host, "core", name);

		if value == nil then

			value = default_value;

		end

	end

	return value;

end

function api:get_option_string(name, default_value)

	local value = self:get_option(name, default_value);

	if type(value) == "table" then

		if #value > 1 then

			self:log("error", "Config option '%s' does not take a list, using just the first item", name);

		end

		value = value[1];

	end

	if value == nil then

		return nil;

	end

	return tostring(value);

end

function api:get_option_number(name, ...)

	local value = self:get_option(name, ...);

	if type(value) == "table" then

		if #value > 1 then

			self:log("error", "Config option '%s' does not take a list, using just the first item", name);

		end

		value = value[1];

	end

	local ret = tonumber(value);