/*
 * 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 android.telecom;

import android.app.ActivityManager;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Process;
import android.os.UserHandle;
import android.provider.Settings;
import android.text.TextUtils;

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

Class for managing the default dialer application that will receive incoming calls, and be
allowed to make emergency outgoing calls.
@hide
/**
 * Class for managing the default dialer application that will receive incoming calls, and be
 * allowed to make emergency outgoing calls.
 *
 * @hide
 */
public class DefaultDialerManager {
    private static final String TAG = "DefaultDialerManager";

    
Sets the specified package name as the default dialer application for the current user.
The caller of this method needs to have permission to write to secure settings and
manage users on the device.
Returns:
true if the default dialer application was successfully changed, false otherwise.
@hide
/**
     * Sets the specified package name as the default dialer application for the current user.
     * The caller of this method needs to have permission to write to secure settings and
     * manage users on the device.
     *
     * @return {@code true} if the default dialer application was successfully changed,
     *         {@code false} otherwise.
     *
     * @hide
     * */
    public static boolean setDefaultDialerApplication(Context context, String packageName) {
        return setDefaultDialerApplication(context, packageName, ActivityManager.getCurrentUser());
    }

    
Sets the specified package name as the default dialer application for the specified user.
The caller of this method needs to have permission to write to secure settings and
manage users on the device.
Returns:
true if the default dialer application was successfully changed, false otherwise.
@hide
/**
     * Sets the specified package name as the default dialer application for the specified user.
     * The caller of this method needs to have permission to write to secure settings and
     * manage users on the device.
     *
     * @return {@code true} if the default dialer application was successfully changed,
     *         {@code false} otherwise.
     *
     * @hide
     * */
    public static boolean setDefaultDialerApplication(Context context, String packageName,
            int user) {
        // Get old package name
        String oldPackageName = Settings.Secure.getStringForUser(context.getContentResolver(),
                Settings.Secure.DIALER_DEFAULT_APPLICATION, user);

        if (packageName != null && oldPackageName != null && packageName.equals(oldPackageName)) {
            // No change
            return false;
        }

        // Only make the change if the new package belongs to a valid phone application
        List<String> packageNames = getInstalledDialerApplications(context);

        if (packageNames.contains(packageName)) {
            // Update the secure setting.
            Settings.Secure.putStringForUser(context.getContentResolver(),
                    Settings.Secure.DIALER_DEFAULT_APPLICATION, packageName, user);
            return true;
        }
        return false;
    }

    
Returns the installed dialer application for the current user that will be used to receive
incoming calls, and is allowed to make emergency calls.
The application will be returned in order of preference:
1) User selected phone application (if still installed)
2) Pre-installed system dialer (if not disabled)
3) Null
The caller of this method needs to have permission to manage users on the device.
@hide
/**
     * Returns the installed dialer application for the current user that will be used to receive
     * incoming calls, and is allowed to make emergency calls.
     *
     * The application will be returned in order of preference:
     * 1) User selected phone application (if still installed)
     * 2) Pre-installed system dialer (if not disabled)
     * 3) Null
     *
     * The caller of this method needs to have permission to manage users on the device.
     *
     * @hide
     * */
    public static String getDefaultDialerApplication(Context context) {
        return getDefaultDialerApplication(context, context.getUserId());
    }

    
Returns the installed dialer application for the specified user that will be used to receive
incoming calls, and is allowed to make emergency calls.
The application will be returned in order of preference:
1) User selected phone application (if still installed)
2) Pre-installed system dialer (if not disabled)
3) Null
The caller of this method needs to have permission to manage users on the device.
@hide
/**
     * Returns the installed dialer application for the specified user that will be used to receive
     * incoming calls, and is allowed to make emergency calls.
     *
     * The application will be returned in order of preference:
     * 1) User selected phone application (if still installed)
     * 2) Pre-installed system dialer (if not disabled)
     * 3) Null
     *
     * The caller of this method needs to have permission to manage users on the device.
     *
     * @hide
     * */
    public static String getDefaultDialerApplication(Context context, int user) {
        String defaultPackageName = Settings.Secure.getStringForUser(context.getContentResolver(),
                Settings.Secure.DIALER_DEFAULT_APPLICATION, user);

        final List<String> packageNames = getInstalledDialerApplications(context, user);

        // Verify that the default dialer has not been disabled or uninstalled.
        if (packageNames.contains(defaultPackageName)) {
            return defaultPackageName;
        }

        // No user-set dialer found, fallback to system dialer
        String systemDialerPackageName = getTelecomManager(context).getSystemDialerPackage();

        if (TextUtils.isEmpty(systemDialerPackageName)) {
            // No system dialer configured at build time
            return null;
        }

        if (packageNames.contains(systemDialerPackageName)) {
            return systemDialerPackageName;
        } else {
            return null;
        }
    }

    
Returns a list of installed and available dialer applications.
In order to appear in the list, a dialer application must implement an intent-filter with
the DIAL intent for the following schemes:
1) Empty scheme
2) tel Uri scheme
@hide
/**
     * Returns a list of installed and available dialer applications.
     *
     * In order to appear in the list, a dialer application must implement an intent-filter with
     * the DIAL intent for the following schemes:
     *
     * 1) Empty scheme
     * 2) tel Uri scheme
     *
     * @hide
     **/
    public static List<String> getInstalledDialerApplications(Context context, int userId) {
        PackageManager packageManager = context.getPackageManager();

        // Get the list of apps registered for the DIAL intent with empty scheme
        Intent intent = new Intent(Intent.ACTION_DIAL);
        List<ResolveInfo> resolveInfoList =
                packageManager.queryIntentActivitiesAsUser(intent, 0, userId);

        List<String> packageNames = new ArrayList<>();

        for (ResolveInfo resolveInfo : resolveInfoList) {
            final ActivityInfo activityInfo = resolveInfo.activityInfo;
            if (activityInfo != null
                    && !packageNames.contains(activityInfo.packageName)
                    // ignore cross profile intent handler
                    && resolveInfo.targetUserId == UserHandle.USER_CURRENT) {
                packageNames.add(activityInfo.packageName);
            }
        }

        final Intent dialIntentWithTelScheme = new Intent(Intent.ACTION_DIAL);
        dialIntentWithTelScheme.setData(Uri.fromParts(PhoneAccount.SCHEME_TEL, "", null));
        return filterByIntent(context, packageNames, dialIntentWithTelScheme, userId);
    }

    public static List<String> getInstalledDialerApplications(Context context) {
        return getInstalledDialerApplications(context, Process.myUserHandle().getIdentifier());
    }

    
Determines if the package name belongs to the user-selected default dialer or the preloaded
system dialer, and thus should be allowed to perform certain privileged operations.
Params:
context – A valid context.
packageName – of the package to check for.
Returns:
true if the provided package name corresponds to the user-selected default dialer or the preloaded system dialer, false otherwise.
@hide
/**
     * Determines if the package name belongs to the user-selected default dialer or the preloaded
     * system dialer, and thus should be allowed to perform certain privileged operations.
     *
     * @param context A valid context.
     * @param packageName of the package to check for.
     *
     * @return {@code true} if the provided package name corresponds to the user-selected default
     *         dialer or the preloaded system dialer, {@code false} otherwise.
     *
     * @hide
     */
    public static boolean isDefaultOrSystemDialer(Context context, String packageName) {
        if (TextUtils.isEmpty(packageName)) {
            return false;
        }
        final TelecomManager tm = getTelecomManager(context);
        return packageName.equals(tm.getDefaultDialerPackage())
                || packageName.equals(tm.getSystemDialerPackage());
    }

    
Filter a given list of package names for those packages that contain an activity that has
an intent filter for a given intent.
Params:
context – A valid context
packageNames – List of package names to filter.
userId – The UserId
Returns:
The filtered list./**
     * Filter a given list of package names for those packages that contain an activity that has
     * an intent filter for a given intent.
     *
     * @param context A valid context
     * @param packageNames List of package names to filter.
     * @param userId The UserId
     * @return The filtered list.
     */
    private static List<String> filterByIntent(Context context, List<String> packageNames,
            Intent intent, int userId) {
        if (packageNames == null || packageNames.isEmpty()) {
            return new ArrayList<>();
        }

        final List<String> result = new ArrayList<>();
        final List<ResolveInfo> resolveInfoList = context.getPackageManager()
                .queryIntentActivitiesAsUser(intent, 0, userId);
        final int length = resolveInfoList.size();
        for (int i = 0; i < length; i++) {
            final ActivityInfo info = resolveInfoList.get(i).activityInfo;
            if (info != null && packageNames.contains(info.packageName)
                    && !result.contains(info.packageName)) {
                result.add(info.packageName);
            }
        }

        return result;
    }


    private static TelecomManager getTelecomManager(Context context) {
        return (TelecomManager) context.getSystemService(Context.TELECOM_SERVICE);
    }
}