/*

* class ActionAppend
*
* This action stores a list, and appends each argument value to the list.
* This is useful to allow an option to be specified multiple times.
* This class inherided from [[Action]]
*
**/

'use strict';

var util = require('util');

var Action = require('../action');

// Constants var c = require('../const');

/*

* new ActionAppend(options)
* - options (object): options hash see [[Action.new]]
*
* Note: options.nargs should be optional for constants
* and more then zero for other
**/

var ActionAppend = module.exports = function ActionAppend(options) {

options = options || {};
if (this.nargs <= 0) {
  throw new Error('nargs for append actions must be > 0; if arg ' +
      'strings are not supplying the value to append, ' +
      'the append const action may be more appropriate');
}
if (!!this.constant && this.nargs !== c.OPTIONAL) {
  throw new Error('nargs must be OPTIONAL to supply const');
}
Action.call(this, options);

}; util.inherits(ActionAppend, Action);

/*

* ActionAppend#call(parser, namespace, values, optionString) -> Void
* - parser (ArgumentParser): current parser
* - namespace (Namespace): namespace for output data
* - values (Array): parsed values
* - optionString (Array): input option string(not parsed)
*
* Call the action. Save result in namespace object
**/

ActionAppend.prototype.call = function (parser, namespace, values) {

var items = (namespace[this.dest] || []).slice();
items.push(values);
namespace.set(this.dest, items);

};