/*
 * Copyright (C) 2014 Vlad Mihalachi
 *
 * This file is part of Turbo Editor.
 *
 * Turbo Editor is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Turbo Editor is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package sharedcode.turboeditor.preferences;

import android.content.Context;
import android.content.res.Configuration;
import android.os.Build;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;

import java.util.ArrayList;
import java.util.List;

import de.greenrobot.event.EventBus;
import sharedcode.turboeditor.R;
import sharedcode.turboeditor.util.EventBusEvents;

/**
 * A {@link PreferenceActivity} that presents a set of application settings. On
 * handset devices, settings are presented as a single list. On tablets,
 * settings are split by category, with category headers shown to the left of
 * the list of settings.
 * <p/>
 * See <a href="http://developer.android.com/design/patterns/settings.html">
 * Android Design: Settings</a> for design guidelines and the <a
 * href="http://developer.android.com/guide/topics/ui/settings.html">Settings
 * API Guide</a> for more information on developing a Settings UI.
 */
public class ExtraSettingsActivity extends PreferenceActivity {
    /**
     * Determines whether to always show the simplified settings UI, where
     * settings are presented in a single list. When false, settings are shown
     * as a master/detail two-pane view on tablets. When true, a single pane is
     * shown on tablets.
     */
    private static final boolean ALWAYS_SIMPLE_PREFS = true;
    boolean encodingChanged = false,
            themeChanged = false,
            keyboardSuggestionsChanged = false;
    /**
     * A preference value change listener that updates the preference's summary
     * to reflect its new value.
     */
    private Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
        @Override
        public boolean onPreferenceChange(Preference preference, Object value) {
            String stringValue = value.toString();

            if (preference instanceof ListPreference) {
                // For list preferences, look up the correct display value in
                // the preference's 'entries' list.
                ListPreference listPreference = (ListPreference) preference;
                int index = listPreference.findIndexOfValue(stringValue);

                // Set the summary to reflect the new value.
                preference.setSummary(
                        index >= 0
                                ? listPreference.getEntries()[index]
                                : null);

            }
            switch (preference.getKey()) {
                case "light_theme":
                    themeChanged = !themeChanged;
                    break;
                case "suggestion_active":
                    keyboardSuggestionsChanged = !keyboardSuggestionsChanged;
                    break;
                case "editor_encoding":
                    encodingChanged = true;
                    break;

            }
            return true;
        }
    };

    /**
     * Helper method to determine if the device has an extra-large screen. For
     * example, 10" tablets are extra-large.
     */
    private static boolean isXLargeTablet(Context context) {
        return (context.getResources().getConfiguration().screenLayout
                & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        boolean light = PreferenceHelper.getLightTheme(this);
        if (light) {
            setTheme(R.style.AppTheme_Light);
        } else {
            setTheme(R.style.AppTheme_Dark);
        }
        super.onCreate(savedInstanceState);
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);

        setupSimplePreferencesScreen();
    }

    /**
     * Shows the simplified settings UI if the device configuration if the
     * device configuration dictates that a simplified, single-pane UI should be
     * shown.
     */
    private void setupSimplePreferencesScreen() {
        if (!isSimplePreferences(this)) {
            return;
        }

        // In the simplified UI, fragments are not used at all and we instead
        // use the older PreferenceActivity APIs.

        // Add 'general' preferences.
        addPreferencesFromResource(R.xml.extra_options);

        // Bind the summaries of EditText/List/Dialog/Ringtone preferences to
        // their values. When their values change, their summaries are updated
        // to reflect the new value, per the Android Design guidelines.
        bindPreferenceSummaryToValue(findPreference("editor_encoding"));

        String[] checkBoxPreferences = {"light_theme", "suggestion_active"};
        for (String key : checkBoxPreferences) {
            // Set the listener to watch for value changes.
            findPreference(key).setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean onIsMultiPane() {
        return isXLargeTablet(this) && !isSimplePreferences(this);
    }

    /**
     * Determines whether the simplified settings UI should be shown. This is
     * true if this is forced via {@link #ALWAYS_SIMPLE_PREFS}, or the device
     * doesn't have newer APIs like {@link PreferenceFragment}, or the device
     * doesn't have an extra-large screen. In these cases, a single-pane
     * "simplified" settings UI should be shown.
     */
    private boolean isSimplePreferences(Context context) {
        return ALWAYS_SIMPLE_PREFS
                || Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB
                || !isXLargeTablet(context);
    }

    @Override
    protected void onDestroy() {
        List<EventBusEvents.APreferenceValueWasChanged.Type> listOfChanges = new ArrayList<>();
        if (themeChanged) {
            listOfChanges.add(EventBusEvents.APreferenceValueWasChanged.Type.THEME_CHANGE);
        }
        if (keyboardSuggestionsChanged) {
            listOfChanges.add(EventBusEvents.APreferenceValueWasChanged.Type.TEXT_SUGGESTIONS);
        }
        if (encodingChanged) {
            listOfChanges.add(EventBusEvents.APreferenceValueWasChanged.Type.ENCODING);
        }


        if (listOfChanges.size() > 0) {
            EventBus.getDefault().postSticky(new EventBusEvents.APreferenceValueWasChanged(listOfChanges));
        }
        super.onDestroy();
    }

    /**
     * Binds a preference's summary to its value. More specifically, when the
     * preference's value is changed, its summary (line of text below the
     * preference title) is updated to reflect the value. The summary is also
     * immediately updated upon calling this method. The exact display format is
     * dependent on the type of preference.
     *
     * @see #sBindPreferenceSummaryToValueListener
     */
    private void bindPreferenceSummaryToValue(Preference preference) {
        // Set the listener to watch for value changes.
        preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);

        // Trigger the listener immediately with the preference's
        // current value.
        sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
                PreferenceManager
                        .getDefaultSharedPreferences(preference.getContext())
                        .getString(preference.getKey(), ""));
    }
}
