var AppDispatcher = require('../dispatcher/appDispatcher');
var EventEmitter = require('events').EventEmitter;
var ItemConstants = require('../constants/itemConstants');
var ItemCollection = require('../models/itemCollection');
var ItemWithDetails = require('../models/itemWithDetails');
var _ = require('underscore');

// Define initial data points
var _items = new ItemCollection(), _selectedItem = new ItemWithDetails();


var loadItemsForFrontpage = function() { 
        items = _items
        items.setClassificationType(0);
        items.setLimit(30);
        items.setOffset(0);
        
        items.fetch({success: function() {
            ItemStore.emitChange();
        }});
};

var setSelected  = function(id) {
  var item = new ItemWithDetails({id: id });
  item.fetch({
    success: function() {            
       _selectedItem = item;
       ItemStore.emitChange();      
     } 
    }
  );
}


// Extend ItemStore with EventEmitter to add eventing capabilities
var ItemStore = _.extend({}, EventEmitter.prototype, {

  // Return Single Item With Details 
  getSelectedItem: function() {
    return _selectedItem;
  },

  // Return All Items
  getItems: function() {
    return _items;
  },

  // Emit Change event
  emitChange: function() {
    console.log("Emitting change!");
    this.emit('change');
  },

  // Add change listener
  addChangeListener: function(callback) {
    this.on('change', callback);
  },

  // Remove change listener
  removeChangeListener: function(callback) {
    this.removeListener('change', callback);
  }

});


// Register callback with AppDispatcher
AppDispatcher.register(function(payload) {
  var action = payload.action;
  var text;

  switch(action.actionType) {

    // Respond to SELECT_ITEM action
    case ItemConstants.SELECT_ITEM:
      setSelected(action.item.id);      
      break;

    case ItemConstants.LOAD_FOR_FRONTPAGE:
      loadItemsForFrontpage();
      break;

    default:
      return true;
  }

  // If action was responded to, emit change event
  ItemStore.emitChange();
  return true;

});

module.exports = ItemStore;