jQuery(function($) {
  var app = new ExplorerApp({
    el: $('.recline-app')
  })
});

var ExplorerApp = Backbone.View.extend({
  events: {
    'submit form.js-import-url': '_onImportURL',
    'submit .js-import-dialog-file form': '_onImportFile'
  },

  initialize: function() {
    this.el = $(this.el);
    this.explorer = null;
    this.explorerDiv = $('.data-explorer-here');
    _.bindAll(this, 'viewExplorer', 'viewHome');

    this.router = new Backbone.Router();
    this.router.route('', 'home', this.viewHome);
    this.router.route(/explorer/, 'explorer', this.viewExplorer);
    Backbone.history.start();

    var state = recline.Util.parseQueryString(window.location.search);
    if (state) {
      _.each(state, function(value, key) {
        try {
          value = JSON.parse(value);
        } catch(e) {}
        state[key] = value;
      });
      if (state.embed) {
        $('.navbar').hide();
        $('body').attr('style', 'padding-top: 0px');
      }
    }
    var dataset = null;
    // special cases for demo / memory dataset
    if (state.url === 'demo' || state.backend === 'memory') {
      dataset = localDataset();
    }
    else if (state.dataset || state.url) {
      dataset = recline.Model.Dataset.restore(state);
    }
    if (dataset) {
      this.createExplorer(dataset, state);
    }
  },

  viewHome: function() {
    this.switchView('home');
  },

  viewExplorer: function() {
    this.router.navigate('explorer');
    this.switchView('explorer');
  },

  switchView: function(path) {
    $('.backbone-page').hide(); 
    var cssClass = path.replace('/', '-');
    $('.page-' + cssClass).show();
  },


  // make Explorer creation / initialization in a function so we can call it
  // again and again
  createExplorer: function(dataset, state) {
    var self = this;
    // remove existing data explorer view
    var reload = false;
    if (this.dataExplorer) {
      this.dataExplorer.remove();
      reload = true;
    }
    this.dataExplorer = null;
    var $el = $('<div />');
    $el.appendTo(this.explorerDiv);
    this.dataExplorer = new recline.View.DataExplorer({
      model: dataset,
      el: $el,
      state: state
    });
    this._setupPermaLink(this.dataExplorer);
    this._setupEmbed(this.dataExplorer);

    this.viewExplorer();
  },

  _setupPermaLink: function(explorer) {
    var self = this;
    var $viewLink = this.el.find('.js-share-and-embed-dialog .view-link');
    explorer.state.bind('change', function() {
      $viewLink.val(self.makePermaLink(explorer.state));
    });
    $viewLink.val(self.makePermaLink(explorer.state));
  },

  _setupEmbed: function(explorer) {
    var self = this;
    var $embedLink = this.el.find('.js-share-and-embed-dialog .view-embed');
    function makeEmbedLink(state) {
      var link = self.makePermaLink(state);
      link = link + '&amp;embed=true';
      var out = $.mustache('<iframe src="{{link}}" width="100%" min-height="500px;"></iframe>', {link: link});
      return out;
    }
    explorer.state.bind('change', function() {
      $embedLink.val(makeEmbedLink(explorer.state));
    });
    $embedLink.val(makeEmbedLink(explorer.state));
  },

  makePermaLink: function(state) {
    var qs = recline.Util.composeQueryString(state.toJSON());
    return window.location.origin + window.location.pathname + qs;
  },

  // setup the loader menu in top bar
  setupLoader: function(callback) {
    // pre-populate webstore load form with an example url
    var demoUrl = 'http://thedatahub.org/api/data/b9aae52b-b082-4159-b46f-7bb9c158d013';
    $('form.js-import-url input[name="source"]').val(demoUrl);
  },

  _onImportURL: function(e) {
    e.preventDefault();
    $('.modal.js-import-dialog-url').modal('hide');
    var $form = $(e.target);
    var source = $form.find('input[name="source"]').val();
    var type = $form.find('select[name="backend_type"]').val();
    var dataset = new recline.Model.Dataset({
        id: 'my-dataset',
        url: source,
        webstore_url: source
      },
      type
    );
    this.createExplorer(dataset);
  },

  _onImportFile: function(e) {
    var self = this;
    e.preventDefault();
    var $form = $(e.target);
    $('.modal.js-import-dialog-file').modal('hide');
    var $file = $form.find('input[type="file"]')[0];
    var file = $file.files[0];
    var options = {
      separator : $form.find('input[name="separator"]').val(),
      delimiter : $form.find('input[name="delimiter"]').val(),
      encoding : $form.find('input[name="encoding"]').val()
    };
    recline.Backend.loadFromCSVFile(file, function(dataset) {
        self.createExplorer(dataset)
      },
      options
    );
  }
});

// provide a demonstration in memory dataset
function localDataset() {
  var dataset = Fixture.getDataset();
  dataset.queryState.addFacet('country');
  return dataset;
}