/* jslint node: true */
'use strict';

//	ENiGMA½
const Config	= require('./config.js').config;

//	deps
const fs 		= require('graceful-fs');
const paths		= require('path');
const _			= require('lodash');
const assert	= require('assert');
const async		= require('async');

//	exports
exports.loadModuleEx			= loadModuleEx;
exports.loadModule				= loadModule;
exports.loadModulesForCategory	= loadModulesForCategory;

function loadModuleEx(options, cb) {
	assert(_.isObject(options));
	assert(_.isString(options.name));
	assert(_.isString(options.path));

	const modConfig = _.isObject(Config[options.category]) ? Config[options.category][options.name] : null;

	if(_.isObject(modConfig) && false === modConfig.enabled) {
		const err	= new Error(`Module "${options.name}" is disabled`);
		err.code	= 'EENIGMODDISABLED'; 
		return cb(err);
	}

	//
	//	Modules are allowed to live in /path/to/<moduleName>/<moduleName>.js or
	//	simply in /path/to/<moduleName>.js. This allows for more advanced modules
	//	to have their own containing folder, package.json & dependencies, etc.
	//
	let mod;
	let modPath = paths.join(options.path, `${options.name}.js`);	//	general case first
	try {		
		mod = require(modPath);
	} catch(e) {
		if('MODULE_NOT_FOUND' === e.code) {
			modPath = paths.join(options.path, options.name, `${options.name}.js`);
			try {
				mod = require(modPath);
			} catch(e) {
				return cb(e);
			}
		} else {
			return cb(e);
		}		
	}

	if(!_.isObject(mod.moduleInfo)) {
		return cb(new Error('Module is missing "moduleInfo" section'));
	}

	if(!_.isFunction(mod.getModule)) {
		return cb(new Error('Invalid or missing "getModule" method for module!'));
	}

	return cb(null, mod);
}

function loadModule(name, category, cb) {
	const path = Config.paths[category];

	if(!_.isString(path)) {
		return cb(new Error(`Not sure where to look for "${name}" of category "${category}"`));
	}

	loadModuleEx( { name : name, path : path, category : category }, function loaded(err, mod) {
		return cb(err, mod);
	});
}

function loadModulesForCategory(category, iterator, complete) {
	
	fs.readdir(Config.paths[category], (err, files) => {
		if(err) {
			return iterator(err);
		}

		const jsModules = files.filter(file => {
			return '.js' === paths.extname(file);
		});

		async.each(jsModules, (file, next) => {
			loadModule(paths.basename(file, '.js'), category, (err, mod) => {
				iterator(err, mod);
				return next();
			});
		}, err => {
			if(complete) {
				return complete(err);
			}
		});
	});
}