/*
 * Copyright (C) 2011 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.server.telecom;

import android.app.ActionBar;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.EditTextPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceScreen;
import android.telecom.Log;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.MenuItem;
import android.widget.Button;

// TODO: This class is newly copied into Telecom (com.android.server.telecom) from it previous
// location in Telephony (com.android.phone). User's preferences stored in the old location
// will be lost. We need code here to migrate KLP -> LMP settings values.

/**
 * Settings activity to manage the responses available for the "Respond via SMS Message" feature to
 * respond to incoming calls.
 */
public class RespondViaSmsSettings extends PreferenceActivity
        implements Preference.OnPreferenceChangeListener {

    private SharedPreferences mPrefs;

    @Override
    protected void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        Log.d(this, "Settings: onCreate()...");

        // This function guarantees that QuickResponses will be in our
        // SharedPreferences with the proper values considering there may be
        // old QuickResponses in Telephony pre L.
        QuickResponseUtils.maybeMigrateLegacyQuickResponses(this);

        getPreferenceManager().setSharedPreferencesName(QuickResponseUtils.SHARED_PREFERENCES_NAME);
        mPrefs = getPreferenceManager().getSharedPreferences();
        QuickResponseUtils.maybeResetQuickResponses(this, mPrefs);
    }

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

        PreferenceScreen preferenceScreen = getPreferenceScreen();
        if (preferenceScreen != null) {
            preferenceScreen.removeAll();
        }

        // This preference screen is ultra-simple; it's just 4 plain
        // <EditTextPreference>s, one for each of the 4 "canned responses".
        //
        // The only nontrivial thing we do here is copy the text value of
        // each of those EditTextPreferences and use it as the preference's
        // "title" as well, so that the user will immediately see all 4
        // strings when they arrive here.
        //
        // Also, listen for change events (since we'll need to update the
        // title any time the user edits one of the strings.)

        addPreferencesFromResource(R.xml.respond_via_sms_settings);
        initPref(findPreference(QuickResponseUtils.KEY_CANNED_RESPONSE_PREF_1));
        initPref(findPreference(QuickResponseUtils.KEY_CANNED_RESPONSE_PREF_2));
        initPref(findPreference(QuickResponseUtils.KEY_CANNED_RESPONSE_PREF_3));
        initPref(findPreference(QuickResponseUtils.KEY_CANNED_RESPONSE_PREF_4));

        ActionBar actionBar = getActionBar();
        if (actionBar != null) {
            // android.R.id.home will be triggered in onOptionsItemSelected()
            actionBar.setDisplayHomeAsUpEnabled(true);
            // set the talkback voice prompt to "Back" instead of "Navigate Up"
            actionBar.setHomeActionContentDescription(R.string.back);
        }
    }

    // Preference.OnPreferenceChangeListener implementation
    @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {
        Log.d(this, "onPreferenceChange: key = %s", preference.getKey());
        Log.d(this, "  preference = '%s'", preference);
        Log.d(this, "  newValue = '%s'", newValue);

        EditTextPreference pref = (EditTextPreference)findPreference(preference.getKey());

        // Copy the new text over to the title, just like in onCreate().
        // (Watch out: onPreferenceChange() is called *before* the
        // Preference itself gets updated, so we need to use newValue here
        // rather than pref.getText().)
        // If the newValue is an empty string, skip this to avoid setting an empty response.
        // TODO: Show a popup to inform user that response didn't set because it's empty.
        if (((String) newValue).length() != 0) {
            pref.setTitle((String) newValue);

            // Save the new preference value.
            SharedPreferences.Editor editor = mPrefs.edit();
            editor.putString(pref.getKey(), (String) newValue).commit();
        }

        // If the user just reset the quick response to its original text, clear the pref.
        QuickResponseUtils.maybeResetQuickResponses(this, mPrefs);

        return true;  // means it's OK to update the state of the Preference with the new value
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        final int itemId = item.getItemId();
        switch (itemId) {
            case android.R.id.home:
                goUpToTopLevelSetting(this);
                return true;
            default:
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * Finish current Activity and go up to the top level Settings.
     */
    public static void goUpToTopLevelSetting(Activity activity) {
        activity.finish();
    }

    /**
     * Initialize the preference to the persisted preference value or default text.
     */
    private void initPref(Preference preference) {
        EditTextPreference pref = (EditTextPreference) preference;
        pref.setText(mPrefs.getString(pref.getKey(), pref.getText()));
        pref.setTitle(pref.getText());
        pref.getEditText().addTextChangedListener(new TextWatcher() {

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {
                try {
                    Button button = ((AlertDialog) pref.getDialog())
                            .getButton(AlertDialog.BUTTON_POSITIVE);
                    if (s.toString().length() == 0) {
                        button.setEnabled(false);
                    } else {
                        button.setEnabled(true);
                    }
                } catch (NullPointerException e) {
                    Log.d(this, e.toString());
                }
            }
        });
        pref.setOnPreferenceChangeListener(this);
    }
}