/*
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.gnd.ui.editobservation;

import android.content.Context;
import android.content.DialogInterface;
import androidx.appcompat.app.AlertDialog;
import com.google.android.gnd.model.form.MultipleChoice;
import com.google.android.gnd.model.form.Option;
import com.google.android.gnd.model.observation.MultipleChoiceResponse;
import com.google.android.gnd.model.observation.Response;
import com.google.auto.value.AutoValue;
import com.google.common.collect.ImmutableList;
import java8.util.Optional;
import java8.util.function.Consumer;

@AutoValue
abstract class SingleSelectDialogFactory extends SelectDialogFactory {

  private int checkedItem;

  private static Builder builder() {
    return new AutoValue_SingleSelectDialogFactory.Builder();
  }

  public static void showSelectDialog(
      Context context,
      String title,
      MultipleChoice multipleChoice,
      Optional<MultipleChoiceResponse> response,
      Consumer<Optional<Response>> consumer) {
    builder()
        .setContext(context)
        .setTitle(title)
        .setMultipleChoice(multipleChoice)
        .setCurrentValue(response)
        .setValueConsumer(consumer)
        .build()
        .show();
  }

  @Override
  protected ImmutableList<Option> getSelectedOptions() {
    if (checkedItem >= 0) {
      return ImmutableList.of(getOption(checkedItem));
    } else {
      return ImmutableList.of();
    }
  }

  @Override
  protected AlertDialog.Builder createDialogBuilder() {
    return super.createDialogBuilder()
        .setSingleChoiceItems(getLabels(), checkedItem, this::onSelect);
  }

  @Override
  protected void initSelectedState() {
    checkedItem =
        getCurrentValue()
            .flatMap(MultipleChoiceResponse::getFirstId)
            .flatMap(getMultipleChoice()::getIndex)
            .orElse(-1);
  }

  private void onSelect(DialogInterface dialog, int which) {
    if (checkedItem == which) {
      // Allow user to toggle values off by tapping selected item.
      checkedItem = -1;
      ((AlertDialog) dialog).getListView().setItemChecked(which, false);
    } else {
      checkedItem = which;
    }
  }

  @AutoValue.Builder
  public abstract static class Builder extends SelectDialogFactory.Builder<Builder> {
    public abstract SingleSelectDialogFactory build();
  }
}

@@ -1254,16 +1254,21 @@
 ckedItem
+ = -1
 ;%0A%0A  pri

Set default checked value for single select