-- 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 array = require "util.array";

local logger = require "util.logger";

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

local config = require "core.configmanager";

local pluginloader = require "util.pluginloader";

local envload = require "util.envload";

local set = require "util.set";

local core_features = require "core.features".available;

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

local api = require "core.moduleapi"; -- Module API container

local prosody = prosody;

local hosts = prosody.hosts;

local xpcall = require "util.xpcall".xpcall;

local debug_traceback = debug.traceback;

local setmetatable, rawget = setmetatable, rawget;

local ipairs, pairs, type, t_insert = ipairs, pairs, type, table.insert;

local lua_version = _VERSION:match("5%.%d$");

local autoload_modules = {

	prosody.platform,

	"presence",

	"message",

	"iq",

	"offline",

	"c2s",

	"s2s",

	"s2s_auth_certs",

};

local component_inheritable_modules = {

	"tls",

	"saslauth",

	"dialback",

	"iq",

	"s2s",

	"s2s_bidi",

	"smacks",

	"server_contact_info",

};

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

local _G = _G;

local _ENV = nil;

-- luacheck: std none

local loader = pluginloader.init({

	load_filter_cb = function (path, content)

		local metadata = {};

		for line in content:gmatch("([^\r\n]+)\r?\n") do

			local key, value = line:match("^%-%-%% *([%w_]+): *(.+)$");

			if key then

				value = value:gsub("%s+$", "");

				metadata[key] = value;

			end

		end

		if metadata.conflicts then

			local conflicts_features = set.new(array.collect(metadata.conflicts:gmatch("[^, ]+")));

			local conflicted_features = set.intersection(conflicts_features, core_features);

			if not conflicted_features:empty() then

				log("warn", "Not loading module, due to conflicting features '%s': %s", conflicted_features, path);

				return; -- Don't load this module

			end

		end

		if metadata.requires then

			local required_features = set.new(array.collect(metadata.requires:gmatch("[^, ]+")));

			local missing_features = required_features - core_features;

			if not missing_features:empty() then

				log("warn", "Not loading module, due to missing features '%s': %s", missing_features, path);

				return; -- Don't load this module

			end

		end

		return path, content, metadata;

	end;

});

local load_modules_for_host, load, unload, reload, get_module, get_items;

local get_modules, is_loaded, module_has_method, call_module_method;

-- [host] = { [module] = module_env }

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

-- Get the list of modules to be loaded on a host

local function get_modules_for_host(host)

	local component = config.get(host, "component_module");

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

	local global_modules_disabled = config.get("*", "modules_disabled");

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

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

	if host_modules_enabled == global_modules_enabled then host_modules_enabled = nil; end

	if host_modules_disabled == global_modules_disabled then host_modules_disabled = nil; end

	local global_modules = set.new(autoload_modules) + set.new(global_modules_enabled) - set.new(global_modules_disabled);

	if component then

		global_modules = set.intersection(set.new(component_inheritable_modules), global_modules);

	end

	local modules = (global_modules + set.new(host_modules_enabled)) - set.new(host_modules_disabled);

	if modules:contains("vcard") and modules:contains("vcard_legacy") then

		log("error", "The mod_vcard_legacy plugin replaces mod_vcard but both are enabled. Please update your config.");

		modules:remove("vcard");

	end

	return modules, component;

end

-- Load modules when a host is activated

function load_modules_for_host(host)

	local modules, component_module = get_modules_for_host(host);

	-- Ensure component module is loaded first

	if component_module then

		load(host, component_module);

	end

	for module in modules do

		load(host, module);

	end

end

prosody.events.add_handler("host-activated", load_modules_for_host);

prosody.events.add_handler("host-deactivated", function (host)

	modulemap[host] = nil;

end);

--- Private helpers ---

local function do_unload_module(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

	for object, event, handler in mod.module.event_handlers:iter(nil, nil, nil) do

		object.remove_handler(event, handler);

	end

	if mod.module.items then -- remove items

		local events = (host == "*" and prosody.events) or hosts[host].events;

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

			for i = #t,1,-1 do

				local value = t[i];

				t[i] = nil;

				events.fire_event("item-removed/"..key, {source = mod.module, item = value});

			end

		end

	end

	mod.module.loaded = false;

	modulemap[host][name] = nil;

	return true;

end

local function do_load_module(host, module_name, state)

	if not (host and module_name) then

		return nil, "insufficient-parameters";

	elseif not hosts[host] and host ~= "*"then

		return nil, "unknown-host";

	end

	if not modulemap[host] then

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

	end

	if modulemap[host][module_name] then

		if not modulemap["*"][module_name] then

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

		end

		return nil, "module-already-loaded";

	elseif modulemap["*"][module_name] then

		local mod = modulemap["*"][module_name];

		if module_has_method(mod, "add_host") then

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

			local host_module_api = setmetatable({

				global = false,

				host = host, event_handlers = new_multitable(), items = {};

				_log = _log, log = function (self, ...) return _log(...); end; --luacheck: ignore 212/self

			},{

				__index = modulemap["*"][module_name].module;

			});

			local host_module = setmetatable({ module = host_module_api }, { __index = mod });

			host_module_api.environment = host_module;

			modulemap[host][module_name] = host_module;

			local ok, result, module_err = call_module_method(mod, "add_host", host_module_api);

			if not ok or result == false then

				modulemap[host][module_name] = nil;

				return nil, ok and module_err or result;

			end

			return host_module;

		end

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

	end

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

	local api_instance = setmetatable({ name = module_name, host = host,

		_log = _log, log = function (self, ...) return _log(...); end, --luacheck: ignore 212/self

		event_handlers = new_multitable(), reloading = not not state,

		saved_state = state~=true and state or nil }

		, { __index = api });

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

	api_instance.environment = pluginenv;

	local mod, err, meta = loader:load_code(module_name, nil, pluginenv);

	if not mod then

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

		api_instance:set_status("error", "Failed to load (see log)");

		return nil, err;

	end

	api_instance.path = err;

	api_instance.meta = meta;

	local custom_plugins = prosody.paths.installer;

	if custom_plugins and err:sub(1, #custom_plugins+1) == custom_plugins.."/" then

		-- Stage 1: Make it work (you are here)

		-- Stage 2: Make it less hacky (TODO)

		local manifest = {};

		local luarocks_path = custom_plugins.."/lib/luarocks/rocks-"..lua_version;

		local manifest_filename = luarocks_path.."/manifest";

		local load_manifest, err = envload.envloadfile(manifest_filename, manifest);

		if not load_manifest then

			-- COMPAT Luarocks 2.x

			log("debug", "Could not load LuaRocks 3.x manifest, trying 2.x", err);

			luarocks_path = custom_plugins.."/lib/luarocks/rocks";

			manifest_filename = luarocks_path.."/manifest";

			load_manifest, err = envload.envloadfile(manifest_filename, manifest);

		end

		if not load_manifest then

			log("error", "Could not load manifest of installed plugins: %s", err, load_manifest);

		else

			local ok, err = xpcall(load_manifest, debug_traceback);

			if not ok then

				log("error", "Could not load manifest of installed plugins: %s", err);

			elseif type(manifest.modules) ~= "table" then

				log("debug", "Expected 'table' but manifest.modules = %q", manifest.modules);

				log("error", "Can't look up resource path for mod_%s because '%s' does not appear to be a LuaRocks manifest", module_name, manifest_filename);

			else

				local versions = manifest.modules["mod_"..module_name];

				if type(versions) == "table" and versions[1] then

					-- Not going to deal with multiple installed versions

					api_instance.resource_path = luarocks_path.."/"..versions[1];

				else

					log("debug", "mod_%s does not appear in the installation manifest", module_name);

				end

			end

		end

	end

	modulemap[host][module_name] = pluginenv;

	local ok, err = xpcall(mod, debug_traceback);

	if ok then

		-- Call module's "load"

		if module_has_method(pluginenv, "load") then

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

			if not ok then

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

				api_instance:set_status("warn", "Error during load (see log)");

			end

		end

		api_instance.reloading, api_instance.saved_state = nil, nil;

		if api_instance.host == "*" then

			if not api_instance.global then -- COMPAT w/pre-0.9

				if host ~= "*" then

					log("warn", "mod_%s: Setting module.host = '*' deprecated, call module:set_global() instead", module_name);

				end

				api_instance:set_global();

			end

			modulemap[host][module_name] = nil;

			modulemap[api_instance.host][module_name] = pluginenv;

			if host ~= api_instance.host and module_has_method(pluginenv, "add_host") then

				-- Now load the module again onto the host it was originally being loaded on

				ok, err = do_load_module(host, module_name);

			end

		end

	end

	if not ok then

		modulemap[api_instance.host][module_name] = nil;

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

		api_instance:set_status("warn", "Error during load (see log)");

	else

		api_instance:set_status("core", "Loaded", false);

	end

	return ok and pluginenv, err;

end

local function do_reload_module(host, name)

	local mod = get_module(host, name);

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

	local _mod, err = loader: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

		-- FIXME What goes in 'err' here?

		local ok, ret, err = call_module_method(mod, "save"); -- luacheck: ignore 211/err

		if ok then

			saved = ret;

		else

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

			if not config.get(host, "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

	mod.module.reloading = true;

	do_unload_module(host, name);

	local ok, err = do_load_module(host, name, saved or true);

	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

	end

	return ok and mod, err;

end

--- Public API ---

-- Load a module and fire module-loaded event

function load(host, name)

	local mod, err = do_load_module(host, name);

	if mod then

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

	end

	return mod, err;

end