define([
  'summernote/base/core/key'
], function (key) {
  var LinkDialog = function (context) {
    var self = this;
    var ui = $.summernote.ui;

    var $editor = context.layoutInfo.editor;
    var options = context.options;
    var lang = options.langInfo;

    this.initialize = function () {
      var $container = options.dialogsInBody ? $(document.body) : $editor;

      var body = '<div class="form-group">' +
                   '<label>' + lang.link.textToDisplay + '</label>' +
                   '<input class="note-link-text form-control" type="text" />' +
                 '</div>' +
                 '<div class="form-group">' +
                   '<label>' + lang.link.url + '</label>' +
                   '<input class="note-link-url form-control" type="text" value="http://" />' +
                 '</div>' +
                 (!options.disableLinkTarget ?
                   '<div class="checkbox">' +
                     '<label for="sn-checkbox-open-in-new-window">' + 
                       '<input type="checkbox" id="sn-checkbox-open-in-new-window" checked />' + lang.link.openInNewWindow +
                     '</label>' +
                   '</div>' : ''
                 );
      var footer = '<button href="#" class="btn btn-primary note-link-btn disabled" disabled>' + lang.link.insert + '</button>';

      this.$dialog = ui.dialog({
        className: 'link-dialog',
        title: lang.link.insert,
        fade: options.dialogsFade,
        body: body,
        footer: footer
      }).render().appendTo($container);
    };

    this.destroy = function () {
      ui.hideDialog(this.$dialog);
      this.$dialog.remove();
    };

    this.bindEnterKey = function ($input, $btn) {
      $input.on('keypress', function (event) {
        if (event.keyCode === key.code.ENTER) {
          $btn.trigger('click');
        }
      });
    };

    /**
     * toggle update button
     */
    this.toggleLinkBtn = function ($linkBtn, $linkText, $linkUrl) {
      ui.toggleBtn($linkBtn, $linkText.val() && $linkUrl.val());
    };

    /**
     * Show link dialog and set event handlers on dialog controls.
     *
     * @param {Object} linkInfo
     * @return {Promise}
     */
    this.showLinkDialog = function (linkInfo) {
      return $.Deferred(function (deferred) {
        var $linkText = self.$dialog.find('.note-link-text'),
        $linkUrl = self.$dialog.find('.note-link-url'),
        $linkBtn = self.$dialog.find('.note-link-btn'),
        $openInNewWindow = self.$dialog.find('input[type=checkbox]');

        ui.onDialogShown(self.$dialog, function () {
          context.triggerEvent('dialog.shown');

          // if no url was given, copy text to url
          if (!linkInfo.url) {
            linkInfo.url = linkInfo.text;
          }

          $linkText.val(linkInfo.text);

          var handleLinkTextUpdate = function () {
            self.toggleLinkBtn($linkBtn, $linkText, $linkUrl);
            // if linktext was modified by keyup,
            // stop cloning text from linkUrl
            linkInfo.text = $linkText.val();
          };

          $linkText.on('input', handleLinkTextUpdate).on('paste', function () {
            setTimeout(handleLinkTextUpdate, 0);
          });

          var handleLinkUrlUpdate = function () {
            self.toggleLinkBtn($linkBtn, $linkText, $linkUrl);
            // display same link on `Text to display` input
            // when create a new link
            if (!linkInfo.text) {
              $linkText.val($linkUrl.val());
            }
          };

          $linkUrl.on('input', handleLinkUrlUpdate).on('paste', function () {
            setTimeout(handleLinkUrlUpdate, 0);
          }).val(linkInfo.url).trigger('focus');

          self.toggleLinkBtn($linkBtn, $linkText, $linkUrl);
          self.bindEnterKey($linkUrl, $linkBtn);
          self.bindEnterKey($linkText, $linkBtn);

          var isChecked = linkInfo.isNewWindow !== undefined ?
            linkInfo.isNewWindow : context.options.linkTargetBlank;

          $openInNewWindow.prop('checked', isChecked);

          $linkBtn.one('click', function (event) {
            event.preventDefault();

            deferred.resolve({
              range: linkInfo.range,
              url: $linkUrl.val(),
              text: $linkText.val(),
              isNewWindow: $openInNewWindow.is(':checked')
            });
            self.$dialog.modal('hide');
          });
        });

        ui.onDialogHidden(self.$dialog, function () {
          // detach events
          $linkText.off('input paste keypress');
          $linkUrl.off('input paste keypress');
          $linkBtn.off('click');

          if (deferred.state() === 'pending') {
            deferred.reject();
          }
        });

        ui.showDialog(self.$dialog);
      }).promise();
    };

    /**
     * @param {Object} layoutInfo
     */
    this.show = function () {
      var linkInfo = context.invoke('editor.getLinkInfo');

      context.invoke('editor.saveRange');
      this.showLinkDialog(linkInfo).then(function (linkInfo) {
        context.invoke('editor.restoreRange');
        context.invoke('editor.createLink', linkInfo);
      }).fail(function () {
        context.invoke('editor.restoreRange');
      });
    };
    context.memo('help.linkDialog.show', options.langInfo.help['linkDialog.show']);
  };

  return LinkDialog;
});
