/*
 * 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.settings.applications;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.UserHandle;
import android.provider.SearchIndexableResource;
import android.provider.Settings;
import android.support.v4.util.ArrayMap;
import android.support.v7.preference.Preference;
import android.support.v7.preference.PreferenceScreen;
import android.text.TextUtils;
import android.util.Log;

import com.android.internal.content.PackageMonitor;
import com.android.internal.logging.MetricsProto.MetricsEvent;
import com.android.settings.PreferenceAvailabilityProvider;
import com.android.settings.R;
import com.android.settings.search.BaseSearchIndexProvider;
import com.android.settings.search.Index;
import com.android.settings.search.Indexable;
import com.android.settings.utils.ProfileSettingsPreferenceFragment;

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

public class ManageDefaultApps extends ProfileSettingsPreferenceFragment
        implements Preference.OnPreferenceClickListener, Indexable {

    private static final String TAG = ManageDefaultApps.class.getSimpleName();

    private static final String KEY_DEFAULT_HOME = "default_home";
    private static final String KEY_ASSIST_AND_VOICE_INPUT = "assist_and_voice_input";
    private static final String KEY_DEFAULT_BROWSER = "default_browser";
    private static final String KEY_DEFAULT_PHONE_APP = "default_phone_app";
    private static final String KEY_DEFAULT_EMERGENCY_APP = "default_emergency_app";
    private static final String KEY_SMS_APPLICATION = "default_sms_app";
    private static final String KEY_DEFAULT_NOTIFICATION_ASST = "default_notification_asst_app";
    private static final String[] PREFERENCE_KEYS = new String[] {
            KEY_DEFAULT_HOME, KEY_ASSIST_AND_VOICE_INPUT, KEY_DEFAULT_BROWSER,
            KEY_DEFAULT_PHONE_APP, KEY_DEFAULT_EMERGENCY_APP, KEY_SMS_APPLICATION,
            KEY_DEFAULT_NOTIFICATION_ASST
    };

    private DefaultBrowserPreference mDefaultBrowserPreference;
    private PackageManager mPm;
    private int myUserId;

    private static final long DELAY_UPDATE_BROWSER_MILLIS = 500;

    private final Handler mHandler = new Handler();

    private final Runnable mUpdateRunnable = new Runnable() {
        @Override
        public void run() {
            updateDefaultBrowserPreference();
        }
    };

    private final PackageMonitor mPackageMonitor = new PackageMonitor() {
        @Override
        public void onPackageAdded(String packageName, int uid) {
            sendUpdate();
        }

        @Override
        public void onPackageAppeared(String packageName, int reason) {
            sendUpdate();
        }

        @Override
        public void onPackageDisappeared(String packageName, int reason) {
            sendUpdate();
        }

        @Override
        public void onPackageRemoved(String packageName, int uid) {
            sendUpdate();
        }

        private void sendUpdate() {
            mHandler.postDelayed(mUpdateRunnable, DELAY_UPDATE_BROWSER_MILLIS);
        }
    };

    private void updateDefaultBrowserPreference() {
        mDefaultBrowserPreference.refreshBrowserApps();

        final PackageManager pm = getPackageManager();

        String packageName = pm.getDefaultBrowserPackageNameAsUser(UserHandle.myUserId());
        if (!TextUtils.isEmpty(packageName)) {
            // Check if the default Browser package is still there
            Intent intent = new Intent();
            intent.setPackage(packageName);
            intent.setAction(Intent.ACTION_VIEW);
            intent.addCategory(Intent.CATEGORY_BROWSABLE);
            intent.setData(Uri.parse("http:"));

            ResolveInfo info = mPm.resolveActivityAsUser(intent, 0, myUserId);
            if (info != null) {
                mDefaultBrowserPreference.setValue(packageName);
                CharSequence label = info.loadLabel(pm);
                mDefaultBrowserPreference.setSummary(label);
            } else {
                mDefaultBrowserPreference.setSummary(R.string.default_browser_title_none);
            }
        } else {
            mDefaultBrowserPreference.setSummary(R.string.default_browser_title_none);
            Log.d(TAG, "Cannot set empty default Browser value!");
        }
    }

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

        addPreferencesFromResource(R.xml.default_apps);

        mPm = getPackageManager();
        myUserId = UserHandle.myUserId();


        mDefaultBrowserPreference = (DefaultBrowserPreference) findPreference(KEY_DEFAULT_BROWSER);
        mDefaultBrowserPreference.setOnPreferenceChangeListener(
                new Preference.OnPreferenceChangeListener() {
                    @Override
                    public boolean onPreferenceChange(Preference preference, Object newValue) {

                        if (newValue == null) {
                            return false;
                        }
                        final CharSequence packageName = (CharSequence) newValue;
                        if (TextUtils.isEmpty(packageName)) {
                            return false;
                        }
                        boolean result = mPm.setDefaultBrowserPackageNameAsUser(
                                packageName.toString(), myUserId);
                        if (result) {
                            mDefaultBrowserPreference.setValue(packageName.toString());
                            final CharSequence appName = mDefaultBrowserPreference.getEntry();
                            mDefaultBrowserPreference.setSummary(appName);
                        }
                        return result;
                    }
                });

        updatePreferenceVisibility();
        // Update the index.
        Index.getInstance(getActivity()).updateFromClassNameResource(
                ManageDefaultApps.class.getName(), true, true);
    }

    /**
     * Iterate all preferences and hide it if it is unavailable.
     */
    private void updatePreferenceVisibility() {
        PreferenceScreen preferenceScreen = getPreferenceScreen();
        int count = preferenceScreen.getPreferenceCount();
        List<String> preferenceKeys = new ArrayList<>();
        for (int i = 0; i < count; i++) {
            String preferenceKey = preferenceScreen.getPreference(i).getKey();
            if (!TextUtils.isEmpty(preferenceKey)) {
                preferenceKeys.add(preferenceKey);
            }
        }
        for (String preferenceKey : preferenceKeys) {
            boolean isAvailable = getPreferenceAvailability(getContext(), preferenceKey);
            if (!isAvailable) {
                Preference preference = preferenceScreen.findPreference(preferenceKey);
                preferenceScreen.removePreference(preference);
            }
        }
    }

    /**
     * Get availability of preference from {@link PreferenceAvailabilityProvider}.
     */
    private static boolean getPreferenceAvailability(Context context,
                                              String preferenceKey) {
        // Consider the preference is unavailable if no corresponding provider is found.
        PreferenceAvailabilityProvider provider = getPreferenceAvailabilityProvider(preferenceKey);
        return (provider == null) ? false : provider.isAvailable(context);
    }

    private static PreferenceAvailabilityProvider getPreferenceAvailabilityProvider(
            String preferenceKey) {
        switch (preferenceKey) {
            case KEY_ASSIST_AND_VOICE_INPUT:
                return new ManageAssist.AvailabilityProvider();
            case KEY_DEFAULT_BROWSER:
                return new DefaultBrowserPreference.AvailabilityProvider();
            case KEY_DEFAULT_EMERGENCY_APP:
                return new DefaultEmergencyPreference.AvailabilityProvider();
            case KEY_DEFAULT_HOME:
                return new DefaultHomePreference.AvailabilityProvider();
            case KEY_DEFAULT_NOTIFICATION_ASST:
                return new DefaultNotificationAssistantPreference.AvailabilityProvider();
            case KEY_DEFAULT_PHONE_APP:
                return new DefaultPhonePreference.AvailabilityProvider();
            case KEY_SMS_APPLICATION:
                return new DefaultSmsPreference.AvailabilityProvider();
        }
        Log.w(TAG, "getPreferenceAvailabilityProvider: Cannot find provider for " + preferenceKey);
        return null;
    }

    @Override
    public void onResume() {
        super.onResume();
        updateDefaultBrowserPreference();
        mPackageMonitor.register(getActivity(), getActivity().getMainLooper(), false);
    }

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

        mPackageMonitor.unregister();
    }

    @Override
    protected int getMetricsCategory() {
        return MetricsEvent.APPLICATIONS_DEFAULT_APPS;
    }

    @Override
    public boolean onPreferenceClick(Preference preference) {
        return false;
    }

    public static final Indexable.SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
            new BaseSearchIndexProvider() {
                @Override
                public List<SearchIndexableResource> getXmlResourcesToIndex(
                        Context context, boolean enabled) {
                    SearchIndexableResource sir = new SearchIndexableResource(context);
                    sir.xmlResId = R.xml.default_apps;
                    return Arrays.asList(sir);
                }

                @Override
                public List<String> getNonIndexableKeys(Context context) {
                    // Iterate all preferences to see which is not available.
                    final ArrayList<String> result = new ArrayList<>();
                    for (String key : PREFERENCE_KEYS) {
                        boolean isAvailable = getPreferenceAvailability(context, key);
                        if (!isAvailable) {
                            result.add(key);
                        }
                    }
                    return result;
                }
            };

    protected String getIntentActionString() {
        return Settings.ACTION_MANAGE_DEFAULT_APPS_SETTINGS;
    }

}