/*

 * Copyright (C) 2008 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;

import android.app.Dialog;

import android.app.DatePickerDialog;

import android.app.TimePickerDialog;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.content.SharedPreferences;

import android.content.SharedPreferences.OnSharedPreferenceChangeListener;

import android.os.Bundle;

import android.os.SystemClock;

import android.preference.CheckBoxPreference;

import android.preference.ListPreference;

import android.preference.Preference;

import android.preference.PreferenceActivity;

import android.preference.PreferenceScreen;

import android.provider.Settings;

import android.provider.Settings.SettingNotFoundException;

import android.text.format.DateFormat;

import android.widget.DatePicker;

import android.widget.TimePicker;

import java.util.Calendar;

import java.util.Date;

import java.util.TimeZone;

public class DateTimeSettings 

        extends PreferenceActivity 

        implements OnSharedPreferenceChangeListener,

                TimePickerDialog.OnTimeSetListener , DatePickerDialog.OnDateSetListener {

    private static final String HOURS_12 = "12";

    private static final String HOURS_24 = "24";

    private Calendar mDummyDate;

    private static final String KEY_DATE_FORMAT = "date_format";

    private static final String KEY_AUTO_TIME = "auto_time";

    private static final int DIALOG_DATEPICKER = 0;

    private static final int DIALOG_TIMEPICKER = 1;

    private CheckBoxPreference mAutoPref;

    private Preference mTimePref;

    private Preference mTime24Pref;

    private Preference mTimeZone;

    private Preference mDatePref;

    private ListPreference mDateFormat;

    @Override

    protected void onCreate(Bundle icicle) {

        super.onCreate(icicle);

        addPreferencesFromResource(R.xml.date_time_prefs);

        initUI();        

    }

    private void initUI() {

        boolean autoEnabled = getAutoState();

        mDummyDate = Calendar.getInstance();

        mDummyDate.set(mDummyDate.get(Calendar.YEAR), 11, 31, 13, 0, 0);

        mAutoPref = (CheckBoxPreference) findPreference(KEY_AUTO_TIME);

        mAutoPref.setChecked(autoEnabled);

        mTimePref = findPreference("time");

        mTime24Pref = findPreference("24 hour");

        mTimeZone = findPreference("timezone");

        mDatePref = findPreference("date");

        mDateFormat = (ListPreference) findPreference(KEY_DATE_FORMAT);

        String [] dateFormats = getResources().getStringArray(R.array.date_format_values);

        String [] formattedDates = new String[dateFormats.length];

        String currentFormat = getDateFormat();

        // Initialize if DATE_FORMAT is not set in the system settings

        // This can happen after a factory reset (or data wipe)

        if (currentFormat == null) {

            currentFormat = "";

        }

        for (int i = 0; i < formattedDates.length; i++) {

            String formatted =

                DateFormat.getDateFormatForSetting(this, dateFormats[i]).

                    format(mDummyDate.getTime());

            if (dateFormats[i].length() == 0) {

                formattedDates[i] = getResources().

                    getString(R.string.normal_date_format, formatted);

            } else {

                formattedDates[i] = formatted;

            }

        }

        mDateFormat.setEntries(formattedDates);

        mDateFormat.setEntryValues(R.array.date_format_values);

        mDateFormat.setValue(currentFormat);

        mTimePref.setEnabled(!autoEnabled);

        mDatePref.setEnabled(!autoEnabled);

        mTimeZone.setEnabled(!autoEnabled);

    }

    @Override

    protected void onResume() {

        super.onResume();

        getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);

        ((CheckBoxPreference)mTime24Pref).setChecked(is24Hour());

        // Register for time ticks and other reasons for time change

        IntentFilter filter = new IntentFilter();

        filter.addAction(Intent.ACTION_TIME_TICK);

        filter.addAction(Intent.ACTION_TIME_CHANGED);

        filter.addAction(Intent.ACTION_TIMEZONE_CHANGED);

        registerReceiver(mIntentReceiver, filter, null, null);

        updateTimeAndDateDisplay();

    }

    @Override 

    protected void onPause() {

        super.onPause();

        unregisterReceiver(mIntentReceiver);

        getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);

    }

    private void updateTimeAndDateDisplay() {

        java.text.DateFormat shortDateFormat = DateFormat.getDateFormat(this);

        Date now = Calendar.getInstance().getTime();

        Date dummyDate = mDummyDate.getTime();

        mTimePref.setSummary(DateFormat.getTimeFormat(this).format(now));

        mTimeZone.setSummary(getTimeZoneText());

        mDatePref.setSummary(shortDateFormat.format(now));

        mDateFormat.setSummary(shortDateFormat.format(dummyDate));

    }

    public void onDateSet(DatePicker view, int year, int month, int day) {

        Calendar c = Calendar.getInstance();

        c.set(Calendar.YEAR, year);

        c.set(Calendar.MONTH, month);

        c.set(Calendar.DAY_OF_MONTH, day);

        long when = c.getTimeInMillis();

        if (when / 1000 < Integer.MAX_VALUE) {

            SystemClock.setCurrentTimeMillis(when);

        }

        updateTimeAndDateDisplay();

    }

    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {

        Calendar c = Calendar.getInstance();

        c.set(Calendar.HOUR_OF_DAY, hourOfDay);

        c.set(Calendar.MINUTE, minute);

        long when = c.getTimeInMillis();

        if (when / 1000 < Integer.MAX_VALUE) {

            SystemClock.setCurrentTimeMillis(when);

        }

        updateTimeAndDateDisplay();

        // We don't need to call timeUpdated() here because the TIME_CHANGED

        // broadcast is sent by the AlarmManager as a side effect of setting the

        // SystemClock time.

    }

    public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {

        if (key.equals(KEY_DATE_FORMAT)) {

            String format = preferences.getString(key, 

                    getResources().getString(R.string.default_date_format));

            Settings.System.putString(getContentResolver(), 

                    Settings.System.DATE_FORMAT, format);

            updateTimeAndDateDisplay();

        } else if (key.equals(KEY_AUTO_TIME)) {

            boolean autoEnabled = preferences.getBoolean(key, true);

            Settings.System.putInt(getContentResolver(), 

                    Settings.System.AUTO_TIME, 

                    autoEnabled ? 1 : 0);

            mTimePref.setEnabled(!autoEnabled);

            mDatePref.setEnabled(!autoEnabled);

            mTimeZone.setEnabled(!autoEnabled);

        }

    }

    @Override

    public Dialog onCreateDialog(int id) {

        Dialog d;

        switch (id) {

        case DIALOG_DATEPICKER: {

            final Calendar calendar = Calendar.getInstance();

            d = new DatePickerDialog(

                this,

                this,

                calendar.get(Calendar.YEAR),

                calendar.get(Calendar.MONTH),

                calendar.get(Calendar.DAY_OF_MONTH));

            d.setTitle(getResources().getString(R.string.date_time_changeDate_text));

            break;

        }

        case DIALOG_TIMEPICKER: {

            final Calendar calendar = Calendar.getInstance();

            d = new TimePickerDialog(

                    this,

                    this,

                    calendar.get(Calendar.HOUR_OF_DAY),

                    calendar.get(Calendar.MINUTE),

                    DateFormat.is24HourFormat(this));

            d.setTitle(getResources().getString(R.string.date_time_changeTime_text));

            break;

        }

        default:

            d = null;

            break;

        }

        return d;

    }

    @Override

    public void onPrepareDialog(int id, Dialog d) {

        switch (id) {

        case DIALOG_DATEPICKER: {

            DatePickerDialog datePicker = (DatePickerDialog)d;

            final Calendar calendar = Calendar.getInstance();

            datePicker.updateDate(

                    calendar.get(Calendar.YEAR),

                    calendar.get(Calendar.MONTH),

                    calendar.get(Calendar.DAY_OF_MONTH));

            break;

        }

        case DIALOG_TIMEPICKER: {

            TimePickerDialog timePicker = (TimePickerDialog)d;

            final Calendar calendar = Calendar.getInstance();

            timePicker.updateTime(

                    calendar.get(Calendar.HOUR_OF_DAY),

                    calendar.get(Calendar.MINUTE));

            break;

        }

        default:

            break;

        }

    }

    @Override

    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {

        if (preference == mDatePref) {

            showDialog(DIALOG_DATEPICKER);

        } else if (preference == mTimePref) {

            // The 24-hour mode may have changed, so recreate the dialog

            removeDialog(DIALOG_TIMEPICKER);

            showDialog(DIALOG_TIMEPICKER);

        } else if (preference == mTime24Pref) {

            set24Hour(((CheckBoxPreference)mTime24Pref).isChecked());

            updateTimeAndDateDisplay();

            timeUpdated();

        } else if (preference == mTimeZone) {

            Intent intent = new Intent();

            intent.setClass(this, ZoneList.class);

            startActivityForResult(intent, 0);

        }

        return false;

    }

    @Override

    protected void onActivityResult(int requestCode, int resultCode,

            Intent data) {

        updateTimeAndDateDisplay();

    }

    private void timeUpdated() {

        Intent timeChanged = new Intent(Intent.ACTION_TIME_CHANGED);

        sendBroadcast(timeChanged);

    }

    /*  Get & Set values from the system settings  */

    private boolean is24Hour() {

        return DateFormat.is24HourFormat(this);

    }

    private void set24Hour(boolean is24Hour) {

        Settings.System.putString(getContentResolver(),

                Settings.System.TIME_12_24,

                is24Hour? HOURS_24 : HOURS_12);

    }

    private String getDateFormat() {

        return Settings.System.getString(getContentResolver(), 

                Settings.System.DATE_FORMAT);

    }

    private boolean getAutoState() {

        try {

            return Settings.System.getInt(getContentResolver(), 

                Settings.System.AUTO_TIME) > 0;            

        } catch (SettingNotFoundException snfe) {

            return true;

        }

    }

    private void setDateFormat(String format) {

        if (format.length() == 0) {

            format = null;

        }

        Settings.System.putString(getContentResolver(), Settings.System.DATE_FORMAT, format);        

    }

    /*  Helper routines to format timezone */

    private String getTimeZoneText() {

        TimeZone    tz = java.util.Calendar.getInstance().getTimeZone();

        boolean daylight = tz.inDaylightTime(new Date());

        StringBuilder sb = new StringBuilder();

        sb.append(formatOffset(tz.getRawOffset() +

                               (daylight ? tz.getDSTSavings() : 0))).

            append(", ").

            append(tz.getDisplayName(daylight, TimeZone.LONG));

        return sb.toString();        

    }

    private char[] formatOffset(int off) {

        off = off / 1000 / 60;

        char[] buf = new char[9];

        buf[0] = 'G';

        buf[1] = 'M';

        buf[2] = 'T';

        if (off < 0) {

            buf[3] = '-';

            off = -off;

        } else {

            buf[3] = '+';

        }

        int hours = off / 60; 

        int minutes = off % 60;

        buf[4] = (char) ('0' + hours / 10);

        buf[5] = (char) ('0' + hours % 10);

        buf[6] = ':';

        buf[7] = (char) ('0' + minutes / 10);

        buf[8] = (char) ('0' + minutes % 10);

        return buf;

    }

    private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {

        @Override

        public void onReceive(Context context, Intent intent) {

            updateTimeAndDateDisplay();

        }

    };

}