'use strict';

var assert = require('assert');
var Separator = require('./separator');
var Choice = require('./choice');
var utils = require('../utils/');

/**
 * Choices collection
 * Collection of multiple `choice` object
 * @constructor
 * @param {Array} choices  All `choice` to keep in the collection
 */

var Choices = module.exports = function(choices, answers) {
  this.choices = choices.map(function(val) {
    if (val.type === 'separator') {
      if (!(val instanceof Separator)) {
        val = new Separator(val.line);
      }
      return val;
    }
    return new Choice(val, answers);
  });

  this.realChoices = this.choices
    .filter(Separator.exclude)
    .filter(function(item) {
      return !item.disabled;
    });

  Object.defineProperty(this, 'length', {
    get: function() {
      return this.choices.length;
    },
    set: function(val) {
      this.choices.length = val;
    }
  });

  Object.defineProperty(this, 'realLength', {
    get: function() {
      return this.realChoices.length;
    },
    set: function() {
      throw new Error('Cannot set `realLength` of a Choices collection');
    }
  });
};

/**
 * Get a valid choice from the collection
 * @param  {Number} selector  The selected choice index
 * @return {Choice|Undefined} Return the matched choice or undefined
 */

Choices.prototype.getChoice = function(selector) {
  assert(typeof selector === 'number');
  return this.realChoices[selector];
};

/**
 * Get a raw element from the collection
 * @param  {Number} selector  The selected index value
 * @return {Choice|Undefined} Return the matched choice or undefined
 */

Choices.prototype.get = function(selector) {
  assert(typeof selector === 'number');
  return this.choices[selector];
};

/**
 * Match the valid choices against a where clause
 * @param  {Object} whereClause Lodash `where` clause
 * @return {Array}              Matching choices or empty array
 */

Choices.prototype.where = function(whereClause) {
  return utils.where(this.realChoices, whereClause);
};

/**
 * Pluck a particular key from the choices
 * @param  {String} propertyName Property name to select
 * @return {Array}               Selected properties
 */

Choices.prototype.pluck = function(propertyName) {
  return utils.pluck(this.realChoices, propertyName);
};

// Expose usual Array methods
Choices.prototype.forEach = function() {
  return this.choices.forEach.apply(this.choices, arguments);
};
Choices.prototype.filter = function() {
  return this.choices.filter.apply(this.choices, arguments);
};
Choices.prototype.push = function() {
  var args = [].slice.call(arguments);
  var objs = args.map(function(val) {
    return new Choice(val);
  });
  this.choices.push.apply(this.choices, objs);
  this.realChoices = this.choices.filter(Separator.exclude);
  return this.choices;
};