/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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
 *
 *      http://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.android.dialer.assisteddialing.ui;

import android.annotation.TargetApi;
import android.os.Build.VERSION_CODES;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceFragment;
import android.preference.SwitchPreference;
import android.text.TextUtils;
import com.android.dialer.assisteddialing.ConcreteCreator;
import com.android.dialer.assisteddialing.CountryCodeProvider;
import com.android.dialer.configprovider.ConfigProviderBindings;
import com.android.dialer.logging.DialerImpression;
import com.android.dialer.logging.Logger;
import com.google.auto.value.AutoValue;
import java.util.ArrayList;
import java.util.List;

/** The setting for Assisted Dialing */
@TargetApi(VERSION_CODES.N)
@SuppressWarnings("AndroidApiChecker") // Java 8 APIs
public class AssistedDialingSettingFragment extends PreferenceFragment {

  private CountryCodeProvider countryCodeProvider;

  @AutoValue
  abstract static class DisplayNameAndCountryCodeTuple {

    static DisplayNameAndCountryCodeTuple create(
        CharSequence countryDisplayName, CharSequence countryCode) {
      return new AutoValue_AssistedDialingSettingFragment_DisplayNameAndCountryCodeTuple(
          countryDisplayName, countryCode);
    }

    // The user-readable name of the country.
    abstract CharSequence countryDisplayname();

    // The ISO 3166-2 country code of the country.
    abstract CharSequence countryCode();
  }

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    countryCodeProvider =
        ConcreteCreator.getCountryCodeProvider(ConfigProviderBindings.get(getContext()));

    // Load the preferences from an XML resource
    addPreferencesFromResource(R.xml.assisted_dialing_setting);
    SwitchPreference switchPref =
        (SwitchPreference)
            findPreference(getContext().getString(R.string.assisted_dialing_setting_toggle_key));

    ListPreference countryChooserPref =
        (ListPreference)
            findPreference(getContext().getString(R.string.assisted_dialing_setting_cc_key));

    updateCountryChoices(countryChooserPref);

    if (!TextUtils.isEmpty(countryChooserPref.getEntry())) {
      countryChooserPref.setSummary(countryChooserPref.getEntry());
    }
    countryChooserPref.setOnPreferenceChangeListener(this::updateListSummary);
    switchPref.setOnPreferenceChangeListener(this::logIfUserDisabledFeature);
  }

  /**
   * Filters the default entries in the country chooser by only showing those countries in which the
   * feature in enabled.
   */
  private void updateCountryChoices(ListPreference countryChooserPref) {

    List<DisplayNameAndCountryCodeTuple> defaultCountryChoices =
        buildDefaultCountryChooserKeysAndValues(countryChooserPref);

    // Always include the default preference.
    List<CharSequence> newKeys = new ArrayList<>();
    List<CharSequence> newValues = new ArrayList<>();
    newKeys.add(countryChooserPref.getEntries()[0]);
    newValues.add(countryChooserPref.getEntryValues()[0]);

    for (DisplayNameAndCountryCodeTuple tuple : defaultCountryChoices) {
      if (countryCodeProvider.isSupportedCountryCode(tuple.countryCode().toString())) {
        newKeys.add(tuple.countryDisplayname());
        newValues.add(tuple.countryCode());
      }
    }

    countryChooserPref.setEntries(newKeys.toArray(new CharSequence[newKeys.size()]));
    countryChooserPref.setEntryValues(newValues.toArray(new CharSequence[newValues.size()]));
  }

  private List<DisplayNameAndCountryCodeTuple> buildDefaultCountryChooserKeysAndValues(
      ListPreference countryChooserPref) {
    CharSequence[] keys = countryChooserPref.getEntries();
    CharSequence[] values = countryChooserPref.getEntryValues();

    if (keys.length != values.length) {
      throw new IllegalStateException("Unexpected mismatch in country chooser key/value size");
    }

    List<DisplayNameAndCountryCodeTuple> displayNamesandCountryCodes = new ArrayList<>();
    for (int i = 0; i < keys.length; i++) {
      displayNamesandCountryCodes.add(DisplayNameAndCountryCodeTuple.create(keys[i], values[i]));
    }

    return displayNamesandCountryCodes;
  }

  boolean updateListSummary(Preference pref, Object newValue) {
    ListPreference listPref = (ListPreference) pref;
    CharSequence[] entries = listPref.getEntries();
    listPref.setSummary(entries[listPref.findIndexOfValue(newValue.toString())]);
    return true;
  }

  boolean logIfUserDisabledFeature(Preference pref, Object newValue) {
    if (!((boolean) newValue)) {
      Logger.get(getActivity().getApplicationContext())
          .logImpression(DialerImpression.Type.ASSISTED_DIALING_FEATURE_DISABLED_BY_USER);
    }

    return true;
  }
}