var Backbone = require('backbone');
var CoreView = require('backbone/core-view');
var _ = require('underscore');
var PaginationModel = require('builder/components/pagination/pagination-model');
var PaginationSearchModel = require('./pagination-search-model');
var renderLoading = require('builder/components/loading/render-loading');
var renderNoResults = require('builder/components/no-results/render-no-results');
var ErrorView = require('builder/components/error/error-view');
var template = require('./pagination-search.tpl');
var Utils = require('builder/helpers/utils');
var PaginationView = require('builder/components/pagination/pagination-view');
var paginationTemplate = require('./pagination.tpl');

/**
 * View to render a searchable/pageable collection.
 * Also allows to filter/search list.
 *
 */

var REQUIRED_OPTS = [
  'listCollection',
  'createContentView'
];

var ENTER_KEY_CODE = 13;
var ESCAPE_KEY_CODE = 27;

module.exports = CoreView.extend({

  events: {
    'click .js-search-link': '_onSearchClick',
    'click .js-clean-search': '_onCleanSearchClick',
    'keydown .js-search-input': '_onKeyDown'
  },

  initialize: function (opts) {
    _.each(REQUIRED_OPTS, function (item) {
      if (opts[item] === undefined) throw new Error(item + ' is required');
      this['_' + item] = opts[item];
    }, this);

    this._paginationModel = new PaginationModel({
      current_page: 1
    });

    this._paginationSearchModel = new PaginationSearchModel({}, {
      collection: this._listCollection
    });

    this._stateModel = new Backbone.Model({
      state: 'idle'
    });

    this._initBinds();
    this._initPagination();
    this._paginationSearchModel.fetch();
  },

  render: function () {
    this.clearSubViews();
    this.$el.html(template({
      q: this._paginationSearchModel.get('q')
    }));
    this._initViews();
    return this;
  },

  _initBinds: function () {
    this._paginationSearchModel.on('fetching', this.showLoading, this);
    this._paginationSearchModel.on('fetched', this._updateStateFetched, this);
    this._paginationSearchModel.on('error', this.showError, this);

    this._paginationModel.bind('change:current_page', this._fetchByPagination, this);

    this._stateModel.on('change:state', this.render, this);

    this.add_related_model(this._paginationModel);
    this.add_related_model(this._stateModel);
    this.add_related_model(this._stateModel);
  },

  _fetchByPagination: function () {
    this._paginationSearchModel.set('page', this._paginationModel.get('current_page'));
    this._paginationSearchModel.fetch();
  },

  showError: function () {
    this._stateModel.set('state', 'error');
  },

  showLoading: function () {
    this._stateModel.set('state', 'loading');
  },

  _updateStateFetched: function () {
    this._paginationModel.set({
      per_page: this._paginationSearchModel.get('per_page'),
      total_count: this._listCollection.totalCount()
    });
    if (this._listCollection.length > 0) {
      this._stateModel.set('state', 'show');
    } else {
      this._stateModel.set('state', 'no-results');
    }
  },

  _initPagination: function () {
    this._paginationView = new PaginationView({
      className: 'Pagination Pagination--search Pagination--searchShare',
      model: this._paginationModel,
      template: paginationTemplate
    });
    this.addView(this._paginationView);
  },

  _initViews: function () {
    var state = this._stateModel.get('state');
    var view;

    this.$el.append(this._paginationView.render().el);

    if (state === 'loading') {
      this._content().html(renderLoading({
        title: _t('components.pagination-search.loading.title')
      }));
    }

    if (state === 'error') {
      var errorView = new ErrorView({
        title: _t('components.pagination-search.error.title'),
        desc: _t('components.pagination-search.error.desc')
      });
      this._content().html(errorView.render().el);
      this.addView(errorView);
    }

    if (state === 'show') {
      view = this._createContentView({
        hasOrganization: this._paginationSearchModel.get('q') === ''
      });
      this._content().html(view.render().el);
      this.addView(view);
    }

    if (state === 'no-results') {
      this._content().html(renderNoResults({
        icon: 'CDB-IconFont-defaultUser',
        title: _t('components.pagination-search.no-results.title'),
        desc: _t('components.pagination-search.no-results.desc')
      }));
    }
  },

  _focusSearchInput: function () {
    this._searchInput().focus().val();
  },

  _onSearchClick: function (e) {
    this.killEvent(e);
    this._searchInput().focus();
  },

  _onCleanSearchClick: function (e) {
    this.killEvent(e);
    this._cleanSearch();
  },

  _onKeyDown: function (e) {
    if (e.which === ENTER_KEY_CODE) {
      this.killEvent(e);
      this._submitSearch();
    } else if (e.which === ESCAPE_KEY_CODE) {
      if (this._paginationSearchModel.get('q')) {
        this.killEvent(e);
        this._cleanSearch();
      }
    }
  },

  _submitSearch: function (e) {
    this._makeNewSearch(Utils.stripHTML(this._searchInput().val().trim()));
  },

  _cleanSearch: function () {
    this._searchInput().val('');
    this._makeNewSearch('');
  },

  _makeNewSearch: function (query) {
    this._paginationSearchModel.set({
      q: query,
      page: 1
    });

    this._paginationSearchModel.fetch();
  },

  _searchInput: function () {
    return this.$('.js-search-input');
  },

  _cleanSearchBtn: function () {
    return this.$('.js-clean-search');
  },

  _content: function () {
    return this.$('.js-content');
  }

});