/*
 * Copyright (C) 2016 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.settings.display;

import android.app.Dialog;
import android.app.TimePickerDialog;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.preference.DropDownPreference;
import android.support.v7.preference.Preference;
import android.support.v7.preference.TwoStatePreference;
import android.widget.TimePicker;

import com.android.internal.app.NightDisplayController;
import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
import com.android.settings.R;
import com.android.settings.widget.SeekBarPreference;
import com.android.settings.SettingsPreferenceFragment;

import java.text.DateFormat;
import java.time.LocalTime;
import java.util.Calendar;
import java.util.TimeZone;

/**
 * Settings screen for Night display.
 */
public class NightDisplaySettings extends SettingsPreferenceFragment
        implements NightDisplayController.Callback, Preference.OnPreferenceChangeListener {

    private static final String KEY_NIGHT_DISPLAY_AUTO_MODE = "night_display_auto_mode";
    private static final String KEY_NIGHT_DISPLAY_START_TIME = "night_display_start_time";
    private static final String KEY_NIGHT_DISPLAY_END_TIME = "night_display_end_time";
    private static final String KEY_NIGHT_DISPLAY_ACTIVATED = "night_display_activated";
    private static final String KEY_NIGHT_DISPLAY_TEMPERATURE = "night_display_temperature";

    private static final int DIALOG_START_TIME = 0;
    private static final int DIALOG_END_TIME = 1;

    private NightDisplayController mController;
    private DateFormat mTimeFormatter;

    private DropDownPreference mAutoModePreference;
    private Preference mStartTimePreference;
    private Preference mEndTimePreference;
    private TwoStatePreference mActivatedPreference;
    private SeekBarPreference mTemperaturePreference;

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

        final Context context = getContext();
        mController = new NightDisplayController(context);

        mTimeFormatter = android.text.format.DateFormat.getTimeFormat(context);
        mTimeFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));

        mTemperaturePreference.setMax(convertTemperature(mController.getMinimumColorTemperature()));
        mTemperaturePreference.setContinuousUpdates(true);
    }

    @Override
    protected int getHelpResource() {
        return R.string.help_url_night_display;
    }

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        super.onCreatePreferences(savedInstanceState, rootKey);

        // Load the preferences from xml.
        addPreferencesFromResource(R.xml.night_display_settings);
        mFooterPreferenceMixin.createFooterPreference().setTitle(R.string.night_display_text);
        mAutoModePreference = (DropDownPreference) findPreference(KEY_NIGHT_DISPLAY_AUTO_MODE);
        mStartTimePreference = findPreference(KEY_NIGHT_DISPLAY_START_TIME);
        mEndTimePreference = findPreference(KEY_NIGHT_DISPLAY_END_TIME);
        mActivatedPreference = (TwoStatePreference) findPreference(KEY_NIGHT_DISPLAY_ACTIVATED);
        mTemperaturePreference = (SeekBarPreference) findPreference(KEY_NIGHT_DISPLAY_TEMPERATURE);

        mAutoModePreference.setEntries(new CharSequence[] {
                getString(R.string.night_display_auto_mode_never),
                getString(R.string.night_display_auto_mode_custom),
                getString(R.string.night_display_auto_mode_twilight)
        });
        mAutoModePreference.setEntryValues(new CharSequence[] {
                String.valueOf(NightDisplayController.AUTO_MODE_DISABLED),
                String.valueOf(NightDisplayController.AUTO_MODE_CUSTOM),
                String.valueOf(NightDisplayController.AUTO_MODE_TWILIGHT)
        });
        mAutoModePreference.setOnPreferenceChangeListener(this);
        mActivatedPreference.setOnPreferenceChangeListener(this);
        mTemperaturePreference.setOnPreferenceChangeListener(this);
    }

    @Override
    public void onStart() {
        super.onStart();

        // Listen for changes only while visible.
        mController.setListener(this);

        // Update the current state since it have changed while not visible.
        onActivated(mController.isActivated());
        onAutoModeChanged(mController.getAutoMode());
        onCustomStartTimeChanged(mController.getCustomStartTime());
        onCustomEndTimeChanged(mController.getCustomEndTime());
        onColorTemperatureChanged(mController.getColorTemperature());
        onDisplayColorModeChanged(mController.getColorMode());
    }

    @Override
    public void onStop() {
        super.onStop();

        // Stop listening for state changes.
        mController.setListener(null);
    }

    @Override
    public boolean onPreferenceTreeClick(Preference preference) {
        if (preference == mStartTimePreference) {
            showDialog(DIALOG_START_TIME);
            return true;
        } else if (preference == mEndTimePreference) {
            showDialog(DIALOG_END_TIME);
            return true;
        }
        return super.onPreferenceTreeClick(preference);
    }

    @Override
    public Dialog onCreateDialog(final int dialogId) {
        if (dialogId == DIALOG_START_TIME || dialogId == DIALOG_END_TIME) {
            final LocalTime initialTime;
            if (dialogId == DIALOG_START_TIME) {
                initialTime = mController.getCustomStartTime();
            } else {
                initialTime = mController.getCustomEndTime();
            }

            final Context context = getContext();
            final boolean use24HourFormat = android.text.format.DateFormat.is24HourFormat(context);
            return new TimePickerDialog(context, new TimePickerDialog.OnTimeSetListener() {
                @Override
                public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                    final LocalTime time = LocalTime.of(hourOfDay, minute);
                    if (dialogId == DIALOG_START_TIME) {
                        mController.setCustomStartTime(time);
                    } else {
                        mController.setCustomEndTime(time);
                    }
                }
            }, initialTime.getHour(), initialTime.getMinute(), use24HourFormat);
        }
        return super.onCreateDialog(dialogId);
    }

    @Override
    public int getDialogMetricsCategory(int dialogId) {
        switch (dialogId) {
            case DIALOG_START_TIME:
                return MetricsEvent.DIALOG_NIGHT_DISPLAY_SET_START_TIME;
            case DIALOG_END_TIME:
                return MetricsEvent.DIALOG_NIGHT_DISPLAY_SET_END_TIME;
            default:
                return 0;
        }
    }

    @Override
    public void onActivated(boolean activated) {
        mActivatedPreference.setChecked(activated);
        mTemperaturePreference.setEnabled(activated);
    }

    @Override
    public void onAutoModeChanged(int autoMode) {
        mAutoModePreference.setValue(String.valueOf(autoMode));

        final boolean showCustomSchedule = autoMode == NightDisplayController.AUTO_MODE_CUSTOM;
        mStartTimePreference.setVisible(showCustomSchedule);
        mEndTimePreference.setVisible(showCustomSchedule);
    }

    @Override
    public void onColorTemperatureChanged(int colorTemperature) {
        mTemperaturePreference.setProgress(convertTemperature(colorTemperature));
    }

    private String getFormattedTimeString(LocalTime localTime) {
        final Calendar c = Calendar.getInstance();
        c.setTimeZone(mTimeFormatter.getTimeZone());
        c.set(Calendar.HOUR_OF_DAY, localTime.getHour());
        c.set(Calendar.MINUTE, localTime.getMinute());
        c.set(Calendar.SECOND, 0);
        c.set(Calendar.MILLISECOND, 0);
        return mTimeFormatter.format(c.getTime());
    }

    /**
     * Inverts and range-adjusts a raw value from the SeekBar (i.e. [0, maxTemp-minTemp]), or
     * converts an inverted and range-adjusted value to the raw SeekBar value, depending on the
     * adjustment status of the input.
     */
    private int convertTemperature(int temperature) {
        return mController.getMaximumColorTemperature() - temperature;
    }

    @Override
    public void onCustomStartTimeChanged(LocalTime startTime) {
        mStartTimePreference.setSummary(getFormattedTimeString(startTime));
    }

    @Override
    public void onCustomEndTimeChanged(LocalTime endTime) {
        mEndTimePreference.setSummary(getFormattedTimeString(endTime));
    }

    @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {
        if (preference == mAutoModePreference) {
            return mController.setAutoMode(Integer.parseInt((String) newValue));
        } else if (preference == mActivatedPreference) {
            return mController.setActivated((Boolean) newValue);
        } else if (preference == mTemperaturePreference) {
            return mController.setColorTemperature(convertTemperature((Integer) newValue));
        }
        return false;
    }

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