/*
 * Copyright (C) 2009 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.accessibility;

import android.accessibilityservice.AccessibilityServiceInfo;
import android.accessibilityservice.AccessibilityShortcutInfo;
import android.app.settings.SettingsEnums;
import android.content.ComponentName;
import android.content.Context;
import android.content.pm.ServiceInfo;
import android.hardware.input.InputManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.UserHandle;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.ArrayMap;
import android.util.Pair;
import android.view.InputDevice;
import android.view.accessibility.AccessibilityManager;

import androidx.annotation.NonNull;
import androidx.annotation.VisibleForTesting;
import androidx.preference.Preference;
import androidx.preference.PreferenceCategory;

import com.android.internal.accessibility.AccessibilityShortcutController;
import com.android.internal.accessibility.util.AccessibilityUtils;
import com.android.internal.content.PackageMonitor;
import com.android.settings.R;
import com.android.settings.accessibility.AccessibilityUtil.AccessibilityServiceFragmentType;
import com.android.settings.dashboard.DashboardFragment;
import com.android.settings.inputmethod.PhysicalKeyboardFragment;
import com.android.settings.overlay.FeatureFactory;
import com.android.settings.search.BaseSearchIndexProvider;
import com.android.settingslib.RestrictedPreference;
import com.android.settingslib.core.AbstractPreferenceController;
import com.android.settingslib.search.SearchIndexable;
import com.android.settingslib.search.SearchIndexableRaw;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

/** Activity with the accessibility settings. */
@SearchIndexable(forTarget = SearchIndexable.ALL & ~SearchIndexable.ARC)
public class AccessibilitySettings extends DashboardFragment implements
        InputManager.InputDeviceListener {

    private static final String TAG = "AccessibilitySettings";

    // Preference categories
    private static final String CATEGORY_SCREEN_READER = "screen_reader_category";
    private static final String CATEGORY_CAPTIONS = "captions_category";
    private static final String CATEGORY_AUDIO = "audio_category";
    private static final String CATEGORY_SPEECH = "speech_category";
    private static final String CATEGORY_DISPLAY = "display_category";
    private static final String CATEGORY_DOWNLOADED_SERVICES = "user_installed_services_category";
    private static final String CATEGORY_KEYBOARD_OPTIONS = "physical_keyboard_options_category";
    @VisibleForTesting
    static final String CATEGORY_INTERACTION_CONTROL = "interaction_control_category";

    private static final String[] CATEGORIES = new String[]{
            CATEGORY_SCREEN_READER, CATEGORY_CAPTIONS, CATEGORY_AUDIO, CATEGORY_DISPLAY,
            CATEGORY_SPEECH, CATEGORY_INTERACTION_CONTROL,
            CATEGORY_KEYBOARD_OPTIONS, CATEGORY_DOWNLOADED_SERVICES
    };

    // Extras passed to sub-fragments.
    static final String EXTRA_PREFERENCE_KEY = "preference_key";
    static final String EXTRA_CHECKED = "checked";
    static final String EXTRA_TITLE = "title";
    static final String EXTRA_RESOLVE_INFO = "resolve_info";
    static final String EXTRA_SUMMARY = "summary";
    static final String EXTRA_INTRO = "intro";
    static final String EXTRA_SETTINGS_TITLE = "settings_title";
    static final String EXTRA_COMPONENT_NAME = "component_name";
    static final String EXTRA_SETTINGS_COMPONENT_NAME = "settings_component_name";
    static final String EXTRA_TILE_SERVICE_COMPONENT_NAME = "tile_service_component_name";
    static final String EXTRA_LAUNCHED_FROM_SUW = "from_suw";
    static final String EXTRA_ANIMATED_IMAGE_RES = "animated_image_res";
    static final String EXTRA_HTML_DESCRIPTION = "html_description";
    static final String EXTRA_TIME_FOR_LOGGING = "start_time_to_log_a11y_tool";
    static final String EXTRA_METRICS_CATEGORY = "metrics_category";

    // Timeout before we update the services if packages are added/removed
    // since the AccessibilityManagerService has to do that processing first
    // to generate the AccessibilityServiceInfo we need for proper
    // presentation.
    private static final long DELAY_UPDATE_SERVICES_MILLIS = 1000;

    private final Handler mHandler = new Handler();

    private final Runnable mUpdateRunnable = new Runnable() {
        @Override
        public void run() {
            if (getActivity() != null) {
                onContentChanged();
            }
        }
    };

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

        @Override
        public void onPackageModified(@NonNull String packageName) {
            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_SERVICES_MILLIS);
        }
    };

    @VisibleForTesting
    final AccessibilitySettingsContentObserver mSettingsContentObserver;

    private final Map<String, PreferenceCategory> mCategoryToPrefCategoryMap =
            new ArrayMap<>();
    @VisibleForTesting
    final Map<Preference, PreferenceCategory> mServicePreferenceToPreferenceCategoryMap =
            new ArrayMap<>();
    private final Map<ComponentName, PreferenceCategory> mPreBundledServiceComponentToCategoryMap =
            new ArrayMap<>();

    private boolean mNeedPreferencesUpdate = false;
    private boolean mIsForeground = true;

    public AccessibilitySettings() {
        // Observe changes to anything that the shortcut can toggle, so we can reflect updates
        final Collection<AccessibilityShortcutController.FrameworkFeatureInfo> features =
                AccessibilityShortcutController.getFrameworkShortcutFeaturesMap().values();
        final List<String> shortcutFeatureKeys = new ArrayList<>(features.size());
        for (AccessibilityShortcutController.FrameworkFeatureInfo feature : features) {
            final String key = feature.getSettingKey();
            if (key != null) {
                shortcutFeatureKeys.add(key);
            }
        }

        // Observe changes from accessibility selection menu
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_BUTTON_TARGETS);
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_SHORTCUT_TARGET_SERVICE);
        if (android.view.accessibility.Flags.a11yQsShortcut()) {
            shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_QS_TARGETS);
        }
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_STICKY_KEYS);
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_SLOW_KEYS);
        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_BOUNCE_KEYS);
        mSettingsContentObserver = new AccessibilitySettingsContentObserver(mHandler);
        mSettingsContentObserver.registerKeysToObserverCallback(shortcutFeatureKeys,
                key -> onContentChanged());
    }

    @Override
    public int getMetricsCategory() {
        return SettingsEnums.ACCESSIBILITY;
    }

    @Override
    public int getHelpResource() {
        return R.string.help_uri_accessibility;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        use(AccessibilityHearingAidPreferenceController.class)
                .setFragmentManager(getFragmentManager());
    }

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        initializeAllPreferences();
        updateAllPreferences();
        mNeedPreferencesUpdate = false;
        registerContentMonitors();
        registerInputDeviceListener();
    }

    @Override
    public void onStart() {
        super.onStart();
        mIsForeground = true;
    }

    @Override
    public void onResume() {
        super.onResume();
        if (mNeedPreferencesUpdate) {
            updateAllPreferences();
            mNeedPreferencesUpdate = false;
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        mNeedPreferencesUpdate = true;
    }

    @Override
    public void onStop() {
        mIsForeground = false;
        super.onStop();
    }

    @Override
    public void onDestroy() {
        unregisterContentMonitors();
        unRegisterInputDeviceListener();
        super.onDestroy();
    }

    @Override
    protected int getPreferenceScreenResId() {
        return R.xml.accessibility_settings;
    }

    @Override
    protected String getLogTag() {
        return TAG;
    }

    /**
     * Returns the summary for the current state of this accessibilityService.
     *
     * @param context        A valid context
     * @param info           The accessibilityService's info
     * @param serviceEnabled Whether the accessibility service is enabled.
     * @return The service summary
     */
    public static CharSequence getServiceSummary(Context context, AccessibilityServiceInfo info,
                                                 boolean serviceEnabled) {
        if (serviceEnabled && info.crashed) {
            return context.getText(R.string.accessibility_summary_state_stopped);
        }

        final CharSequence serviceState;
        final int fragmentType = AccessibilityUtil.getAccessibilityServiceFragmentType(info);
        if (fragmentType == AccessibilityServiceFragmentType.INVISIBLE_TOGGLE) {
            final ComponentName componentName = new ComponentName(
                    info.getResolveInfo().serviceInfo.packageName,
                    info.getResolveInfo().serviceInfo.name);
            final boolean shortcutEnabled = AccessibilityUtil.getUserShortcutTypesFromSettings(
                    context, componentName) != AccessibilityUtil.UserShortcutType.EMPTY;
            serviceState = shortcutEnabled
                    ? context.getText(R.string.accessibility_summary_shortcut_enabled)
                    : context.getText(R.string.generic_accessibility_feature_shortcut_off);
        } else {
            serviceState = serviceEnabled
                    ? context.getText(R.string.generic_accessibility_service_on)
                    : context.getText(R.string.generic_accessibility_service_off);
        }

        final CharSequence serviceSummary = info.loadSummary(context.getPackageManager());
        final String stateSummaryCombo = context.getString(
                R.string.preference_summary_default_combination,
                serviceState, serviceSummary);

        return TextUtils.isEmpty(serviceSummary) ? serviceState : stateSummaryCombo;
    }

    /**
     * Returns the description for the current state of this accessibilityService.
     *
     * @param context        A valid context
     * @param info           The accessibilityService's info
     * @param serviceEnabled Whether the accessibility service is enabled.
     * @return The service description
     */
    public static CharSequence getServiceDescription(Context context, AccessibilityServiceInfo info,
            boolean serviceEnabled) {
        if (serviceEnabled && info.crashed) {
            return context.getText(R.string.accessibility_description_state_stopped);
        }

        return info.loadDescription(context.getPackageManager());
    }

    @VisibleForTesting
    void onContentChanged() {
        // If the fragment is visible then update preferences immediately, else set the flag then
        // wait for the fragment to show up to update preferences.
        if (mIsForeground) {
            updateAllPreferences();
        } else {
            mNeedPreferencesUpdate = true;
        }
    }

    private void initializeAllPreferences() {
        for (int i = 0; i < CATEGORIES.length; i++) {
            PreferenceCategory prefCategory = findPreference(CATEGORIES[i]);
            mCategoryToPrefCategoryMap.put(CATEGORIES[i], prefCategory);
        }
    }

    @VisibleForTesting
    void updateAllPreferences() {
        updateServicePreferences();
        updatePreferencesState();
        updateSystemPreferences();
    }

    private void registerContentMonitors() {
        final Context context = getActivity();

        mSettingsPackageMonitor.register(context, context.getMainLooper(), /* externalStorage= */
                false);
        mSettingsContentObserver.register(getContentResolver());
    }

    private void registerInputDeviceListener() {
        InputManager mIm = getSystemService(InputManager.class);
        if (mIm == null) {
            return;
        }
        mIm.registerInputDeviceListener(this, null);
    }

    private void unRegisterInputDeviceListener() {
        InputManager mIm = getSystemService(InputManager.class);
        if (mIm == null) {
            return;
        }
        mIm.unregisterInputDeviceListener(this);
    }

    private void unregisterContentMonitors() {
        mSettingsPackageMonitor.unregister();
        mSettingsContentObserver.unregister(getContentResolver());
    }

    protected void updateServicePreferences() {
        // Since services category is auto generated we have to do a pass
        // to generate it since services can come and go and then based on
        // the global accessibility state to decided whether it is enabled.
        final ArrayList<Preference> servicePreferences =
                new ArrayList<>(mServicePreferenceToPreferenceCategoryMap.keySet());
        for (int i = 0; i < servicePreferences.size(); i++) {
            Preference service = servicePreferences.get(i);
            PreferenceCategory category = mServicePreferenceToPreferenceCategoryMap.get(service);
            category.removePreference(service);
        }

        initializePreBundledServicesMapFromArray(CATEGORY_SCREEN_READER,
                R.array.config_preinstalled_screen_reader_services);
        initializePreBundledServicesMapFromArray(CATEGORY_CAPTIONS,
                R.array.config_preinstalled_captions_services);
        initializePreBundledServicesMapFromArray(CATEGORY_AUDIO,
                R.array.config_preinstalled_audio_services);
        initializePreBundledServicesMapFromArray(CATEGORY_DISPLAY,
                R.array.config_preinstalled_display_services);
        initializePreBundledServicesMapFromArray(CATEGORY_SPEECH,
                R.array.config_preinstalled_speech_services);
        initializePreBundledServicesMapFromArray(CATEGORY_INTERACTION_CONTROL,
                R.array.config_preinstalled_interaction_control_services);

        // ACCESSIBILITY_MENU_IN_SYSTEM is a default pre-bundled interaction control service.
        // If the device opts out of including this service then this is a no-op.
        mPreBundledServiceComponentToCategoryMap.put(
                AccessibilityUtils.ACCESSIBILITY_MENU_IN_SYSTEM,
                mCategoryToPrefCategoryMap.get(CATEGORY_INTERACTION_CONTROL));

        final List<RestrictedPreference> preferenceList = getInstalledAccessibilityList(
                getPrefContext());

        final PreferenceCategory downloadedServicesCategory =
                mCategoryToPrefCategoryMap.get(CATEGORY_DOWNLOADED_SERVICES);

        for (int i = 0, count = preferenceList.size(); i < count; ++i) {
            final RestrictedPreference preference = preferenceList.get(i);
            final ComponentName componentName = preference.getExtras().getParcelable(
                    EXTRA_COMPONENT_NAME);
            PreferenceCategory prefCategory = downloadedServicesCategory;
            // Set the appropriate category if the service comes pre-installed.
            if (mPreBundledServiceComponentToCategoryMap.containsKey(componentName)) {
                prefCategory = mPreBundledServiceComponentToCategoryMap.get(componentName);
            }
            prefCategory.addPreference(preference);
            mServicePreferenceToPreferenceCategoryMap.put(preference, prefCategory);
        }

        // Update the order of all the category according to the order defined in xml file.
        updateCategoryOrderFromArray(CATEGORY_SCREEN_READER,
                R.array.config_order_screen_reader_services);
        updateCategoryOrderFromArray(CATEGORY_CAPTIONS,
                R.array.config_order_captions_services);
        updateCategoryOrderFromArray(CATEGORY_AUDIO,
                R.array.config_order_audio_services);
        updateCategoryOrderFromArray(CATEGORY_INTERACTION_CONTROL,
                R.array.config_order_interaction_control_services);
        updateCategoryOrderFromArray(CATEGORY_DISPLAY,
                R.array.config_order_display_services);
        updateCategoryOrderFromArray(CATEGORY_SPEECH,
                R.array.config_order_speech_services);

        // Need to check each time when updateServicePreferences() called.
        if (downloadedServicesCategory.getPreferenceCount() == 0) {
            getPreferenceScreen().removePreference(downloadedServicesCategory);
        } else {
            getPreferenceScreen().addPreference(downloadedServicesCategory);
        }

        // Hide category if it is empty.
        updatePreferenceCategoryVisibility(CATEGORY_SCREEN_READER);
        updatePreferenceCategoryVisibility(CATEGORY_SPEECH);
        updatePreferenceCategoryVisibility(CATEGORY_KEYBOARD_OPTIONS);
    }

    private List<RestrictedPreference> getInstalledAccessibilityList(Context context) {
        final AccessibilityManager a11yManager = AccessibilityManager.getInstance(context);
        final RestrictedPreferenceHelper preferenceHelper = new RestrictedPreferenceHelper(context);

        final List<AccessibilityShortcutInfo> installedShortcutList =
                a11yManager.getInstalledAccessibilityShortcutListAsUser(context,
                        UserHandle.myUserId());
        final List<AccessibilityActivityPreference> activityList =
                preferenceHelper.createAccessibilityActivityPreferenceList(installedShortcutList);
        final Set<Pair<String, CharSequence>> packageLabelPairs =
                activityList.stream()
                        .map(a11yActivityPref -> new Pair<>(
                                a11yActivityPref.getPackageName(), a11yActivityPref.getLabel())
                        ).collect(Collectors.toSet());

        // Remove duplicate item here, new a ArrayList to copy unmodifiable list result
        // (getInstalledAccessibilityServiceList).
        final List<AccessibilityServiceInfo> installedServiceList = new ArrayList<>(
                a11yManager.getInstalledAccessibilityServiceList());
        if (!packageLabelPairs.isEmpty()) {
            installedServiceList.removeIf(
                    target -> containsPackageAndLabelInList(packageLabelPairs, target));
        }
        final List<RestrictedPreference> serviceList =
                preferenceHelper.createAccessibilityServicePreferenceList(installedServiceList);

        final List<RestrictedPreference> preferenceList = new ArrayList<>();
        preferenceList.addAll(activityList);
        preferenceList.addAll(serviceList);

        return preferenceList;
    }

    private boolean containsPackageAndLabelInList(
            Set<Pair<String, CharSequence>> packageLabelPairs,
            AccessibilityServiceInfo targetServiceInfo) {
        final ServiceInfo serviceInfo = targetServiceInfo.getResolveInfo().serviceInfo;
        final String servicePackageName = serviceInfo.packageName;
        final CharSequence serviceLabel = serviceInfo.loadLabel(getPackageManager());

        return packageLabelPairs.contains(new Pair<>(servicePackageName, serviceLabel));
    }

    private void initializePreBundledServicesMapFromArray(String categoryKey, int key) {
        String[] services = getResources().getStringArray(key);
        PreferenceCategory category = mCategoryToPrefCategoryMap.get(categoryKey);
        for (int i = 0; i < services.length; i++) {
            ComponentName component = ComponentName.unflattenFromString(services[i]);
            mPreBundledServiceComponentToCategoryMap.put(component, category);
        }
    }

    /**
     * Update the order of preferences in the category by matching their preference
     * key with the string array of preference order which is defined in the xml.
     *
     * @param categoryKey The key of the category need to update the order
     * @param key         The key of the string array which defines the order of category
     */
    private void updateCategoryOrderFromArray(String categoryKey, int key) {
        String[] services = getResources().getStringArray(key);
        PreferenceCategory category = mCategoryToPrefCategoryMap.get(categoryKey);
        int preferenceCount = category.getPreferenceCount();
        int serviceLength = services.length;
        for (int preferenceIndex = 0; preferenceIndex < preferenceCount; preferenceIndex++) {
            for (int serviceIndex = 0; serviceIndex < serviceLength; serviceIndex++) {
                if (category.getPreference(preferenceIndex).getKey()
                        .equals(services[serviceIndex])) {
                    category.getPreference(preferenceIndex).setOrder(serviceIndex);
                    break;
                }
            }
        }
    }

    /**
     * Updates the visibility of a category according to its child preference count.
     *
     * @param categoryKey The key of the category which needs to check
     */
    private void updatePreferenceCategoryVisibility(String categoryKey) {
        final PreferenceCategory category = mCategoryToPrefCategoryMap.get(categoryKey);
        category.setVisible(category.getPreferenceCount() != 0);
    }

    /**
     * Updates preferences related to system configurations.
     */
    protected void updateSystemPreferences() {
        updateKeyboardPreferencesVisibility();
    }

    private void updatePreferencesState() {
        final List<AbstractPreferenceController> controllers = new ArrayList<>();
        getPreferenceControllers().forEach(controllers::addAll);
        controllers.forEach(controller -> controller.updateState(
                findPreference(controller.getPreferenceKey())));
    }

    private void updateKeyboardPreferencesVisibility() {
        if (!mCategoryToPrefCategoryMap.containsKey(CATEGORY_KEYBOARD_OPTIONS)) {
            return;
        }
        boolean isVisible = isAnyHardKeyboardsExist()
                && isAnyKeyboardPreferenceAvailable();
        mCategoryToPrefCategoryMap.get(CATEGORY_KEYBOARD_OPTIONS).setVisible(
                isVisible);
        if (isVisible) {
            //set summary here.
            findPreference(KeyboardBounceKeyPreferenceController.PREF_KEY).setSummary(
                    getContext().getString(R.string.bounce_keys_summary,
                            PhysicalKeyboardFragment.BOUNCE_KEYS_THRESHOLD));
            findPreference(KeyboardSlowKeyPreferenceController.PREF_KEY).setSummary(
                    getContext().getString(R.string.slow_keys_summary,
                            PhysicalKeyboardFragment.SLOW_KEYS_THRESHOLD));
        }
    }

    private boolean isAnyHardKeyboardsExist() {
        for (int deviceId : InputDevice.getDeviceIds()) {
            final InputDevice device = InputDevice.getDevice(deviceId);
            if (device != null && !device.isVirtual() && device.isFullKeyboard()) {
                return true;
            }
        }
        return false;
    }

    private boolean isAnyKeyboardPreferenceAvailable() {
        for (List<AbstractPreferenceController> controllerList : getPreferenceControllers()) {
            for (AbstractPreferenceController controller : controllerList) {
                if (controller.getPreferenceKey().equals(
                        KeyboardBounceKeyPreferenceController.PREF_KEY)
                        || controller.getPreferenceKey().equals(
                        KeyboardSlowKeyPreferenceController.PREF_KEY)
                        || controller.getPreferenceKey().equals(
                        KeyboardStickyKeyPreferenceController.PREF_KEY)) {
                    if (controller.isAvailable()) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
            new BaseSearchIndexProvider(R.xml.accessibility_settings) {
                @Override
                public List<SearchIndexableRaw> getRawDataToIndex(Context context,
                        boolean enabled) {
                    return FeatureFactory.getFeatureFactory()
                            .getAccessibilitySearchFeatureProvider().getSearchIndexableRawData(
                                    context);
                }
            };

    @Override
    public void onInputDeviceAdded(int deviceId) {}

    @Override
    public void onInputDeviceRemoved(int deviceId) {}

    @Override
    public void onInputDeviceChanged(int deviceId) {
        mHandler.postDelayed(mUpdateRunnable, DELAY_UPDATE_SERVICES_MILLIS);
    }
}