var a11yCheckboxGroupBinding = new Shiny.InputBinding();
$.extend(a11yCheckboxGroupBinding, {
  find: function(scope) {
    return $(scope).find(".shiny-input-a11ycheckboxgroup");
  },
  getValue: function(el) {
    // Select the checkbox objects that have name equal to the grouping div's id
    const $objs = $('input:checkbox[name="' + el.id + '"]:checked');
    const values = new Array($objs.length);

    for (let i = 0; i < $objs.length; i++) {
      values[i] = $objs[i].value;
    }

    return values;
  },
  setValue: function(el, value) {
    // Null value should be treated as empty array
    value = value || [];

    // Clear all checkboxes
    $('input:checkbox[name="' + el.id + '"]').prop("checked", false);

    // Accept array
    if (value instanceof Array) {
      for (let i = 0; i < value.length; i++) {
        $('input:checkbox[name="' + el.id + '"][value="' + value[i] + '"]')
          .prop("checked", true);
      }
      // Else assume it's a single value
    } else {
      $('input:checkbox[name="' + el.id + '"][value="' + value + '"]')
      .prop("checked", true);
    }
  },

  getState: function(el) {
    const $objs = $('input:checkbox[name="' + el.id + '"]');

    // Store options in an array of objects, each with with value and label
    const options = new Array($objs.length);

    for (let i = 0; i < options.length; i++) {
      options[i] = {
        value: $objs[i].value,
        label: getLabel($objs[i])
      };
    }

    return {
      label: getLabelNode(el).text(),
      value: this.getValue(el),
      options: options,
    };
  },
  receiveMessage: async function(el, data) {
    const $el = $(el);

    // This will replace all the options
    if (Object.prototype.hasOwnProperty.call(data, "options") && data["options"] !== undefined) {
      // Clear existing options and add each new one
      $el.find("div.shiny-options-group").remove();
      // Backward compatibility: for HTML generated by shinybootstrap2 package
      $el.find("label.checkbox").remove();
      $el.append(data.options);
      $el.find('.select-all-container').appendTo($el)
    }

    if (Object.prototype.hasOwnProperty.call(data, "value") && data["value"] !== undefined) {
      this.setValue(el, data.value);
    }

    if (Object.prototype.hasOwnProperty.call(data, "label") && data["label"] !== undefined) {
       await updateLabel(data.label, $el.find("legend"));
    }

    $(el).trigger("change");
  },
  subscribe: function(el, callback) {
    $(el).on("change.checkboxGroupInputBinding", function () {
      callback(false);
    });
  },
  unsubscribe: function(el) {
    $(el).off(".checkboxGroupInputBinding");
  }
});

Shiny.inputBindings.register(a11yCheckboxGroupBinding);