/*
 * Copyright (C) 2015 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.tv.settings.system;

import android.app.ActivityManager;
import android.app.tvsettings.TvSettingsEnums;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.RemoteException;
import android.util.ArrayMap;
import android.util.Log;

import androidx.annotation.Keep;
import androidx.preference.Preference;
import androidx.preference.PreferenceScreen;

import com.android.internal.app.LocalePicker;
import com.android.internal.logging.nano.MetricsProto;
import com.android.settingslib.development.DevelopmentSettingsEnabler;
import com.android.tv.settings.R;
import com.android.tv.settings.RadioPreference;
import com.android.tv.settings.SettingsPreferenceFragment;

import java.util.List;
import java.util.Locale;
import java.util.Map;

/**
 * The language settings screen in TV Settings.
 */
@Keep
public class LanguageFragment extends SettingsPreferenceFragment {
    private static final String TAG = "LanguageFragment";

    // Pseudo locales used for internal purposes only should not be shown in the
    // language picker.
    private static final String PSEUDO_LOCALE_EN_XC = "en-XC";

    private static final String LANGUAGE_RADIO_GROUP = "language";

    private final Map<String, LocalePicker.LocaleInfo> mLocaleInfoMap = new ArrayMap<>();

    // Adjust this value to keep things relatively responsive without janking animations
    private static final int LANGUAGE_SET_DELAY_MS = 500;
    private final Handler mDelayHandler = new Handler();
    private Locale mNewLocale;
    private final Runnable mSetLanguageRunnable = new Runnable() {
        @Override
        public void run() {
            LocalePicker.updateLocale(mNewLocale);
        }
    };

    public static LanguageFragment newInstance() {
        return new LanguageFragment();
    }

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        final Context themedContext = getPreferenceManager().getContext();
        final PreferenceScreen screen =
                getPreferenceManager().createPreferenceScreen(themedContext);
        screen.setTitle(R.string.system_language);

        Locale currentLocale = null;
        try {
            currentLocale = ActivityManager.getService().getConfiguration()
                    .getLocales().get(0);
        } catch (RemoteException e) {
            Log.e(TAG, "Could not retrieve locale", e);
        }

        final List<LocalePicker.LocaleInfo> localeInfoList =
                LocalePicker.getAllAssetLocales(themedContext,
                        DevelopmentSettingsEnabler.isDevelopmentSettingsEnabled(getContext()));

        Preference activePref = null;
        for (final LocalePicker.LocaleInfo localeInfo : localeInfoList) {
            final String languageTag = localeInfo.getLocale().toLanguageTag();
            if (PSEUDO_LOCALE_EN_XC.equals(languageTag)) {
                continue;
            }
            mLocaleInfoMap.put(languageTag, localeInfo);

            final RadioPreference radioPreference = new RadioPreference(themedContext);
            radioPreference.setKey(languageTag);
            radioPreference.setPersistent(false);
            radioPreference.setTitle(localeInfo.getLabel());
            radioPreference.setRadioGroup(LANGUAGE_RADIO_GROUP);
            radioPreference.setLayoutResource(R.layout.preference_reversed_widget);

            if (localeInfo.getLocale().equals(currentLocale)) {
                radioPreference.setChecked(true);
                activePref = radioPreference;
            }

            screen.addPreference(radioPreference);
        }

        if (activePref != null && savedInstanceState == null) {
            scrollToPreference(activePref);
        }

        setPreferenceScreen(screen);
    }

    @Override
    public boolean onPreferenceTreeClick(Preference preference) {
        if (preference instanceof RadioPreference) {
            final RadioPreference radioPreference = (RadioPreference) preference;
            radioPreference.clearOtherRadioPreferences(getPreferenceScreen());
            if (radioPreference.isChecked()) {
                mNewLocale = mLocaleInfoMap.get(radioPreference.getKey()).getLocale();
                mDelayHandler.removeCallbacks(mSetLanguageRunnable);
                mDelayHandler.postDelayed(mSetLanguageRunnable, LANGUAGE_SET_DELAY_MS);
            } else {
                radioPreference.setChecked(true);
            }
        }
        return super.onPreferenceTreeClick(preference);
    }

    @Override
    public int getMetricsCategory() {
        return MetricsProto.MetricsEvent.SETTINGS_LANGUAGE_CATEGORY;
    }

    @Override
    protected int getPageId() {
        return TvSettingsEnums.SYSTEM_LANGUAGE;
    }
}