require('ember-runtime/mixins/observable');
require('ember-runtime/mixins/mutable_array');
require('ember-runtime/mixins/copyable');

/**
@module ember
@submodule ember-runtime
*/


var get = Ember.get, set = Ember.set;

// Add Ember.Array to Array.prototype. Remove methods with native
// implementations and supply some more optimized versions of generic methods
// because they are so common.
var NativeArray = Ember.Mixin.create(Ember.MutableArray, Ember.Observable, Ember.Copyable, {

  // because length is a built-in property we need to know to just get the
  // original property.
  get: function(key) {
    if (key==='length') return this.length;
    else if ('number' === typeof key) return this[key];
    else return this._super(key);
  },

  objectAt: function(idx) {
    return this[idx];
  },

  // primitive for array support.
  replace: function(idx, amt, objects) {

    if (this.isFrozen) throw Ember.FROZEN_ERROR ;

    // if we replaced exactly the same number of items, then pass only the
    // replaced range. Otherwise, pass the full remaining array length
    // since everything has shifted
    var len = objects ? get(objects, 'length') : 0;
    this.arrayContentWillChange(idx, amt, len);

    if (!objects || objects.length === 0) {
      this.splice(idx, amt) ;
    } else {
      var args = [idx, amt].concat(objects) ;
      this.splice.apply(this,args) ;
    }

    this.arrayContentDidChange(idx, amt, len);
    return this ;
  },

  // If you ask for an unknown property, then try to collect the value
  // from member items.
  unknownProperty: function(key, value) {
    var ret;// = this.reducedProperty(key, value) ;
    if ((value !== undefined) && ret === undefined) {
      ret = this[key] = value;
    }
    return ret ;
  },

  // If browser did not implement indexOf natively, then override with
  // specialized version
  indexOf: function(object, startAt) {
    var idx, len = this.length;

    if (startAt === undefined) startAt = 0;
    else startAt = (startAt < 0) ? Math.ceil(startAt) : Math.floor(startAt);
    if (startAt < 0) startAt += len;

    for(idx=startAt;idx<len;idx++) {
      if (this[idx] === object) return idx ;
    }
    return -1;
  },

  lastIndexOf: function(object, startAt) {
    var idx, len = this.length;

    if (startAt === undefined) startAt = len-1;
    else startAt = (startAt < 0) ? Math.ceil(startAt) : Math.floor(startAt);
    if (startAt < 0) startAt += len;

    for(idx=startAt;idx>=0;idx--) {
      if (this[idx] === object) return idx ;
    }
    return -1;
  },

  copy: function(deep) {
    if (deep) {
      return this.map(function(item){ return Ember.copy(item, true); });
    }

    return this.slice();
  }
});

// Remove any methods implemented natively so we don't override them
var ignore = ['length'];
Ember.EnumerableUtils.forEach(NativeArray.keys(), function(methodName) {
  if (Array.prototype[methodName]) ignore.push(methodName);
});

if (ignore.length>0) {
  NativeArray = NativeArray.without.apply(NativeArray, ignore);
}

/**
  The NativeArray mixin contains the properties needed to to make the native
  Array support Ember.MutableArray and all of its dependent APIs. Unless you
  have `Ember.EXTEND_PROTOTYPES or `Ember.EXTEND_PROTOTYPES.Array` set to
  false, this will be applied automatically. Otherwise you can apply the mixin
  at anytime by calling `Ember.NativeArray.activate`.

  @class NativeArray
  @namespace Ember
  @extends Ember.Mixin
  @uses Ember.MutableArray
  @uses Ember.MutableEnumerable
  @uses Ember.Copyable
  @uses Ember.Freezable
*/
Ember.NativeArray = NativeArray;

/**
  Creates an `Ember.NativeArray` from an Array like object.
  Does not modify the original object.

  @method A
  @for Ember
  @return {Ember.NativeArray}
*/
Ember.A = function(arr){
  if (arr === undefined) { arr = []; }
  return Ember.Array.detect(arr) ? arr : Ember.NativeArray.apply(arr);
};

/**
  Activates the mixin on the Array.prototype if not already applied. Calling
  this method more than once is safe.

  @method activate
  @for Ember.NativeArray
  @static
  @return {void}
*/
Ember.NativeArray.activate = function() {
  NativeArray.apply(Array.prototype);

  Ember.A = function(arr) { return arr || []; };
};

if (Ember.EXTEND_PROTOTYPES === true || Ember.EXTEND_PROTOTYPES.Array) {
  Ember.NativeArray.activate();
}

