declare function require(name:string);
declare var __filename: string;
declare var __dirname: string;

var $ = require('gulp-load-plugins')({lazy: true});
var logs = require('./logs');
var _ = require('lodash');

function CheckArguments(options, settings, task, tasks, done) {
  var args = Array.prototype.slice.call(arguments);
  var len = args.length;

  //check module setting is not empty
  if(typeof(settings) === 'undefined' || !(len >= 4)) {
    throw new Error('default settings missing');
  }

  //check async module and done callback is not empty
  if(!task.async && !(len >= 5)) {
    throw new Error('no promise callback provided');
  }

  //check module setting is not empty
  if(!task.async && !(len >= 5)) {
    throw new Error('no promise callback provided');
  }

  //check module setting is not empty
  if(task.required) {
    var remainer:Array<string> = Object.keys(_.pick(options.modules, task.required));
    if(remainer.length !== task.required.length) {
      $.util.beep();
      logs('==========================================\n');
      logs('> required modules:\n');
      logs('> ' + $.util.colors.magenta('npm install --save ' + task.required.join(' ')));
      logs('==========================================\n');
      throw new Error(task.taskName + ' requires the following npm modules: ' + task.required.join(' '));
    }
  }
}
export = CheckArguments;