/*
 * Copyright (C) 2023 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.credentials;

import android.app.Activity;
import android.app.settings.SettingsEnums;
import android.content.ComponentName;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.UserHandle;
import android.provider.Settings;
import android.service.autofill.AutofillService;
import android.service.autofill.AutofillServiceInfo;
import android.text.Html;
import android.text.TextUtils;

import androidx.preference.Preference;

import com.android.internal.content.PackageMonitor;
import com.android.settings.R;
import com.android.settings.applications.defaultapps.DefaultAppPickerFragment;
import com.android.settingslib.applications.DefaultAppInfo;
import com.android.settingslib.utils.ThreadUtils;
import com.android.settingslib.widget.CandidateInfo;

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

public class DefaultCombinedPicker extends DefaultAppPickerFragment {

    private static final String TAG = "DefaultCombinedPicker";

    public static final String SETTING = Settings.Secure.AUTOFILL_SERVICE;
    public static final Intent AUTOFILL_PROBE = new Intent(AutofillService.SERVICE_INTERFACE);

    /** Extra set when the fragment is implementing ACTION_REQUEST_SET_AUTOFILL_SERVICE. */
    public static final String EXTRA_PACKAGE_NAME = "package_name";

    /** Set when the fragment is implementing ACTION_REQUEST_SET_AUTOFILL_SERVICE. */
    private DialogInterface.OnClickListener mCancelListener;

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

        final Activity activity = getActivity();
        if (activity != null && activity.getIntent().getStringExtra(EXTRA_PACKAGE_NAME) != null) {
            mCancelListener =
                    (d, w) -> {
                        activity.setResult(Activity.RESULT_CANCELED);
                        activity.finish();
                    };
            // If mCancelListener is not null, fragment is started from
            // ACTION_REQUEST_SET_AUTOFILL_SERVICE and we should always use the calling uid.
            mUserId = UserHandle.myUserId();
        }
        mSettingsPackageMonitor.register(activity, activity.getMainLooper(), false);
        update();
    }

    @Override
    protected DefaultAppPickerFragment.ConfirmationDialogFragment newConfirmationDialogFragment(
            String selectedKey, CharSequence confirmationMessage) {
        final AutofillPickerConfirmationDialogFragment fragment =
                new AutofillPickerConfirmationDialogFragment();
        fragment.init(this, selectedKey, confirmationMessage);
        return fragment;
    }

    /**
     * Custom dialog fragment that has a cancel listener used to propagate the result back to caller
     * (for the cases where the picker is launched by {@code
     * android.settings.REQUEST_SET_AUTOFILL_SERVICE}.
     */
    public static class AutofillPickerConfirmationDialogFragment
            extends DefaultAppPickerFragment.ConfirmationDialogFragment {

        @Override
        public void onCreate(Bundle savedInstanceState) {
            final DefaultCombinedPicker target = (DefaultCombinedPicker) getTargetFragment();
            setCancelListener(target.mCancelListener);
            super.onCreate(savedInstanceState);
        }
    }

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

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

    @Override
    protected boolean shouldShowItemNone() {
        return true;
    }

    /** Monitor coming and going auto fill services and calls {@link #update()} when necessary */
    private final PackageMonitor mSettingsPackageMonitor =
            new PackageMonitor() {
                @Override
                public void onPackageAdded(String packageName, int uid) {
                    ThreadUtils.postOnMainThread(() -> update());
                }

                @Override
                public void onPackageModified(String packageName) {
                    ThreadUtils.postOnMainThread(() -> update());
                }

                @Override
                public void onPackageRemoved(String packageName, int uid) {
                    ThreadUtils.postOnMainThread(() -> update());
                }
            };

    /** Update the data in this UI. */
    private void update() {
        updateCandidates();
        addAddServicePreference();
    }

    @Override
    public void onDestroy() {
        mSettingsPackageMonitor.unregister();
        super.onDestroy();
    }

    /**
     * Gets the preference that allows to add a new autofill service.
     *
     * @return The preference or {@code null} if no service can be added
     */
    private Preference newAddServicePreferenceOrNull() {
        final String searchUri =
                Settings.Secure.getStringForUser(
                        getActivity().getContentResolver(),
                        Settings.Secure.AUTOFILL_SERVICE_SEARCH_URI,
                        mUserId);
        if (TextUtils.isEmpty(searchUri)) {
            return null;
        }

        final Intent addNewServiceIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(searchUri));
        final Context context = getPrefContext();
        final Preference preference = new Preference(context);
        preference.setOnPreferenceClickListener(
                p -> {
                    context.startActivityAsUser(addNewServiceIntent, UserHandle.of(mUserId));
                    return true;
                });
        preference.setTitle(R.string.print_menu_item_add_service);
        preference.setIcon(R.drawable.ic_add_24dp);
        preference.setOrder(Integer.MAX_VALUE - 1);
        preference.setPersistent(false);
        return preference;
    }

    /**
     * Add a preference that allows the user to add a service if the market link for that is
     * configured.
     */
    private void addAddServicePreference() {
        final Preference addNewServicePreference = newAddServicePreferenceOrNull();
        if (addNewServicePreference != null) {
            getPreferenceScreen().addPreference(addNewServicePreference);
        }
    }

    @Override
    protected List<DefaultAppInfo> getCandidates() {
        final List<DefaultAppInfo> candidates = new ArrayList<>();
        final List<AutofillServiceInfo> services =
                AutofillServiceInfo.getAvailableServices(getContext(), mUserId);
        for (AutofillServiceInfo asi : services) {
            candidates.add(
                    new DefaultAppInfo(
                            getContext(), mPm, mUserId, asi.getServiceInfo().getComponentName()));
        }

        return candidates;
    }

    public static String getDefaultKey(Context context, int userId) {
        String setting =
                Settings.Secure.getStringForUser(context.getContentResolver(), SETTING, userId);
        if (setting != null) {
            ComponentName componentName = ComponentName.unflattenFromString(setting);
            if (componentName != null) {
                return componentName.flattenToString();
            }
        }
        return null;
    }

    @Override
    protected String getDefaultKey() {
        return getDefaultKey(getContext(), mUserId);
    }

    @Override
    protected CharSequence getConfirmationMessage(CandidateInfo appInfo) {
        if (appInfo == null) {
            return null;
        }
        final CharSequence appName = appInfo.loadLabel();
        final String message =
                getContext()
                        .getString(
                                R.string.credman_autofill_confirmation_message,
                                Html.escapeHtml(appName));
        return Html.fromHtml(message);
    }

    @Override
    protected boolean setDefaultKey(String key) {
        Settings.Secure.putStringForUser(getContext().getContentResolver(), SETTING, key, mUserId);

        // Check if activity was launched from Settings.ACTION_REQUEST_SET_AUTOFILL_SERVICE
        // intent, and set proper result if so...
        final Activity activity = getActivity();
        if (activity != null) {
            final String packageName = activity.getIntent().getStringExtra(EXTRA_PACKAGE_NAME);
            if (packageName != null) {
                final int result =
                        key != null && key.startsWith(packageName)
                                ? Activity.RESULT_OK
                                : Activity.RESULT_CANCELED;
                activity.setResult(result);
                activity.finish();
            }
        }

        // TODO: Notify the rest

        return true;
    }
}