-- 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 _G = _G;

local setmetatable, loadfile, pcall, rawget, rawset, io, error, dofile, type, pairs, table =

      setmetatable, loadfile, pcall, rawget, rawset, io, error, dofile, type, pairs, table;

local format, math_max = string.format, math.max;

local fire_event = prosody and prosody.events.fire_event or function () end;

local lfs = require "lfs";

local path_sep = package.config:sub(1,1);

module "configmanager"

local parsers = {};

local config_mt = { __index = function (t, k) return rawget(t, "*"); end};

local config = setmetatable({ ["*"] = { core = {} } }, config_mt);

-- When host not found, use global

local host_mt = { };

-- When key not found in section, check key in global's section

function section_mt(section_name)

	return { __index = 	function (t, k)

					local section = rawget(config["*"], section_name);

					if not section then return nil; end

					return section[k];

				end

	};

end

function getconfig()

	return config;

end

function get(host, section, key)

	local sec = config[host][section];

	if sec then

		return sec[key];

	end

	return nil;

end

local function set(config, host, section, key, value)

	if host and section and key then

		local hostconfig = rawget(config, host);

		if not hostconfig then

			hostconfig = rawset(config, host, setmetatable({}, host_mt))[host];

		end

		if not rawget(hostconfig, section) then

			hostconfig[section] = setmetatable({}, section_mt(section));

		end

		hostconfig[section][key] = value;

		return true;

	end

	return false;

end

function _M.set(host, section, key, value)

	return set(config, host, section, key, value);

end

-- Helper function to resolve relative paths (needed by config)

do

	local rel_path_start = ".."..path_sep;

	function resolve_relative_path(parent_path, path)

		if path then

			-- Some normalization

			parent_path = parent_path:gsub("%"..path_sep.."+$", "");

			path = path:gsub("^%.%"..path_sep.."+", "");

			local is_relative;

			if path_sep == "/" and path:sub(1,1) ~= "/" then

				is_relative = true;

			elseif path_sep == "\\" and (path:sub(1,1) ~= "/" and path:sub(2,3) ~= ":\\") then

				is_relative = true;

			end

			if is_relative then

				return parent_path..path_sep..path;

			end

		end

		return path;

	end	

end

-- Helper function to convert a glob to a Lua pattern

local function glob_to_pattern(glob)

	return "^"..glob:gsub("[%p*?]", function (c)

		if c == "*" then

			return ".*";

		elseif c == "?" then

			return ".";

		else

			return "%"..c;

		end

	end).."$";

end

function load(filename, format)

	format = format or filename:match("%w+$");

	if parsers[format] and parsers[format].load then

		local f, err = io.open(filename);

		if f then

			local new_config = setmetatable({ ["*"] = { core = {} } }, config_mt);

			local ok, err = parsers[format].load(f:read("*a"), filename, new_config);

			f:close();

			if ok then

				config = new_config;

				fire_event("config-reloaded", {

					filename = filename,

					format = format,

					config = config

				});

			end

			return ok, "parser", err;

		end

		return f, "file", err;

	end

	if not format then

		return nil, "file", "no parser specified";

	else

		return nil, "file", "no parser for "..(format);

	end

end

function save(filename, format)

end

function addparser(format, parser)

	if format and parser then

		parsers[format] = parser;

	end

end

-- _M needed to avoid name clash with local 'parsers'

function _M.parsers()

	local p = {};

	for format in pairs(parsers) do

		table.insert(p, format);

	end

	return p;

end

-- Built-in Lua parser

do

	local loadstring, pcall, setmetatable = _G.loadstring, _G.pcall, _G.setmetatable;

	local setfenv, rawget, tostring = _G.setfenv, _G.rawget, _G.tostring;

	parsers.lua = {};

	function parsers.lua.load(data, config_file, config)

		local env;

		-- The ' = true' are needed so as not to set off __newindex when we assign the functions below

		env = setmetatable({

			Host = true, host = true, VirtualHost = true,

			Component = true, component = true,

			Include = true, include = true, RunScript = true }, {

				__index = function (t, k)

					return rawget(_G, k) or

						function (settings_table)

							config[__currenthost or "*"][k] = settings_table;

						end;

				end,

				__newindex = function (t, k, v)

					set(config, env.__currenthost or "*", "core", k, v);

				end

		});

		rawset(env, "__currenthost", "*") -- Default is global

		function env.VirtualHost(name)

			if rawget(config, name) and rawget(config[name].core, "component_module") then

				error(format("Host %q clashes with previously defined %s Component %q, for services use a sub-domain like conference.%s",

					name, config[name].core.component_module:gsub("^%a+$", { component = "external", muc = "MUC"}), name, name), 0);

			end

			rawset(env, "__currenthost", name);

			-- Needs at least one setting to logically exist :)

			set(config, name or "*", "core", "defined", true);

			return function (config_options)

				rawset(env, "__currenthost", "*"); -- Return to global scope

				for option_name, option_value in pairs(config_options) do

					set(config, name or "*", "core", option_name, option_value);

				end

			end;

		end

		env.Host, env.host = env.VirtualHost, env.VirtualHost;

		function env.Component(name)

			if rawget(config, name) and rawget(config[name].core, "defined") and not rawget(config[name].core, "component_module") then

				error(format("Component %q clashes with previously defined Host %q, for services use a sub-domain like conference.%s",

					name, name, name), 0);

			end

			set(config, name, "core", "component_module", "component");

			-- Don't load the global modules by default

			set(config, name, "core", "load_global_modules", false);

			rawset(env, "__currenthost", name);

			local function handle_config_options(config_options)

				rawset(env, "__currenthost", "*"); -- Return to global scope

				for option_name, option_value in pairs(config_options) do

					set(config, name or "*", "core", option_name, option_value);

				end

			end

			return function (module)

					if type(module) == "string" then

						set(config, name, "core", "component_module", module);

						return handle_config_options;

					end

					return handle_config_options(module);

				end

		end

		env.component = env.Component;

		function env.Include(file, wildcard)

			if file:match("[*?]") then

				local path_pos, glob = file:match("()([^"..path_sep.."]+)$");

				local path = file:sub(1, math_max(path_pos-2,0));

				local config_path = config_file:gsub("[^"..path_sep.."]+$", "");

				if #path > 0 then

					path = resolve_relative_path(config_path, path);

				else

					path = config_path;

				end

				local patt = glob_to_pattern(glob);

				for f in lfs.dir(path) do

					if f:sub(1,1) ~= "." and f:match(patt) then

						env.Include(path..path_sep..f);

					end

				end

			else

				local f, err = io.open(file);

				if f then

					local data = f:read("*a");

					local file = resolve_relative_path(config_file:gsub("[^"..path_sep.."]+$", ""), file);

					local ret, err = parsers.lua.load(data, file, config);

					if not ret then error(err:gsub("%[string.-%]", file), 0); end

				end

				if not f then error("Error loading included "..file..": "..err, 0); end

				return f, err;

			end

		end

		env.include = env.Include;

		function env.RunScript(file)

			return dofile(resolve_relative_path(config_file:gsub("[^"..path_sep.."]+$", ""), file));

		end

		local chunk, err = loadstring(data, "@"..config_file);

		if not chunk then

			return nil, err;

		end

		setfenv(chunk, env);

		local ok, err = pcall(chunk);

		if not ok then

			return nil, err;

		end

		return true;

	end

end

return _M;