/*
 * Copyright (C) 2017 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.content.pm;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.RequiresPermission;
import android.annotation.SystemApi;
import android.app.AppOpsManager.Mode;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.RemoteException;
import android.os.UserHandle;
import android.os.UserManager;
import android.provider.Settings;

import com.android.internal.R;
import com.android.internal.util.UserIcons;

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

/**
 * Class for handling cross profile operations. Apps can use this class to interact with its
 * instance in any profile that is in {@link #getTargetUserProfiles()}. For example, app can
 * use this class to start its main activity in managed profile.
 */
public class CrossProfileApps {

    /**
     * Broadcast signalling that the receiving app's ability to interact across profiles has
     * changed, as defined by the return value of {@link #canInteractAcrossProfiles()}.
     *
     * <p>Apps that have set the {@code android:crossProfile} manifest attribute to {@code true}
     * can receive this broadcast in manifest broadcast receivers. Otherwise, it can only be
     * received by dynamically-registered broadcast receivers.
     */
    public static final String ACTION_CAN_INTERACT_ACROSS_PROFILES_CHANGED =
            "android.content.pm.action.CAN_INTERACT_ACROSS_PROFILES_CHANGED";

    private final Context mContext;
    private final ICrossProfileApps mService;
    private final UserManager mUserManager;
    private final Resources mResources;

    /** @hide */
    public CrossProfileApps(Context context, ICrossProfileApps service) {
        mContext = context;
        mService = service;
        mUserManager = context.getSystemService(UserManager.class);
        mResources = context.getResources();
    }

    /**
     * Starts the specified main activity of the caller package in the specified profile.
     *
     * @param component The ComponentName of the activity to launch, it must be exported and has
     *        action {@link android.content.Intent#ACTION_MAIN}, category
     *        {@link android.content.Intent#CATEGORY_LAUNCHER}. Otherwise, SecurityException will
     *        be thrown.
     * @param targetUser The UserHandle of the profile, must be one of the users returned by
     *        {@link #getTargetUserProfiles()}, otherwise a {@link SecurityException} will
     *        be thrown.
     */
    public void startMainActivity(@NonNull ComponentName component,
            @NonNull UserHandle targetUser) {
        try {
            mService.startActivityAsUser(
                    mContext.getIApplicationThread(),
                    mContext.getPackageName(),
                    mContext.getFeatureId(),
                    component,
                    targetUser.getIdentifier(),
                    true);
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Starts the specified activity of the caller package in the specified profile.
     *
     * <p>The caller must have the {@link android.Manifest.permission#INTERACT_ACROSS_PROFILES}
     * permission and both the caller and target user profiles must be in the same profile group.
     *
     * @param intent The intent to launch. A component in the caller package must be specified.
     * @param targetUser The {@link UserHandle} of the profile; must be one of the users returned by
     *        {@link #getTargetUserProfiles()} if different to the calling user, otherwise a
     *        {@link SecurityException} will be thrown.
     */
    @RequiresPermission(anyOf = {
            android.Manifest.permission.INTERACT_ACROSS_PROFILES,
            android.Manifest.permission.INTERACT_ACROSS_USERS})
    public void startActivity(@NonNull Intent intent, @NonNull UserHandle targetUser) {
        try {
            mService.startActivityAsUserByIntent(
                    mContext.getIApplicationThread(),
                    mContext.getPackageName(),
                    mContext.getFeatureId(),
                    intent,
                    targetUser.getIdentifier());
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Starts the specified activity of the caller package in the specified profile. Unlike
     * {@link #startMainActivity}, this can start any activity of the caller package, not just
     * the main activity.
     * The caller must have the {@link android.Manifest.permission#INTERACT_ACROSS_PROFILES}
     * permission and both the caller and target user profiles must be in the same profile group.
     *
     * @param component The ComponentName of the activity to launch. It must be exported.
     * @param targetUser The UserHandle of the profile, must be one of the users returned by
     *        {@link #getTargetUserProfiles()}, otherwise a {@link SecurityException} will
     *        be thrown.
     * @hide
     */
    @SystemApi
    @RequiresPermission(android.Manifest.permission.INTERACT_ACROSS_PROFILES)
    public void startActivity(@NonNull ComponentName component, @NonNull UserHandle targetUser) {
        try {
            mService.startActivityAsUser(mContext.getIApplicationThread(),
                    mContext.getPackageName(), mContext.getFeatureId(), component,
                    targetUser.getIdentifier(), false);
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Return a list of user profiles that that the caller can use when calling other APIs in this
     * class.
     * <p>
     * A user profile would be considered as a valid target user profile, provided that:
     * <ul>
     * <li>It gets caller app installed</li>
     * <li>It is not equal to the calling user</li>
     * <li>It is in the same profile group of calling user profile</li>
     * <li>It is enabled</li>
     * </ul>
     *
     * @see UserManager#getUserProfiles()
     */
    public @NonNull List<UserHandle> getTargetUserProfiles() {
        try {
            return mService.getTargetUserProfiles(mContext.getPackageName());
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Return a label that calling app can show to user for the semantic of profile switching --
     * launching its own activity in specified user profile. For example, it may return
     * "Switch to work" if the given user handle is the managed profile one.
     *
     * @param userHandle The UserHandle of the target profile, must be one of the users returned by
     *        {@link #getTargetUserProfiles()}, otherwise a {@link SecurityException} will
     *        be thrown.
     * @return a label that calling app can show user for the semantic of launching its own
     *         activity in the specified user profile.
     *
     * @see #startMainActivity(ComponentName, UserHandle)
     */
    public @NonNull CharSequence getProfileSwitchingLabel(@NonNull UserHandle userHandle) {
        verifyCanAccessUser(userHandle);

        final int stringRes = mUserManager.isManagedProfile(userHandle.getIdentifier())
                ? R.string.managed_profile_label
                : R.string.user_owner_label;
        return mResources.getString(stringRes);
    }

    /**
     * Return a drawable that calling app can show to user for the semantic of profile switching --
     * launching its own activity in specified user profile. For example, it may return a briefcase
     * icon if the given user handle is the managed profile one.
     *
     * @param userHandle The UserHandle of the target profile, must be one of the users returned by
     *        {@link #getTargetUserProfiles()}, otherwise a {@link SecurityException} will
     *        be thrown.
     * @return an icon that calling app can show user for the semantic of launching its own
     *         activity in specified user profile.
     *
     * @see #startMainActivity(ComponentName, UserHandle)
     */
    public @NonNull Drawable getProfileSwitchingIconDrawable(@NonNull UserHandle userHandle) {
        verifyCanAccessUser(userHandle);

        final boolean isManagedProfile =
                mUserManager.isManagedProfile(userHandle.getIdentifier());
        if (isManagedProfile) {
            return mResources.getDrawable(R.drawable.ic_corp_badge, null);
        } else {
            return UserIcons.getDefaultUserIcon(
                    mResources, UserHandle.USER_SYSTEM, true /* light */);
        }
    }

    /**
     * Returns whether the calling package can request to interact across profiles.
     *
     * <p>The package's current ability to interact across profiles can be checked with
     * {@link #canInteractAcrossProfiles()}.
     *
     * <p>Specifically, returns whether the following are all true:
     * <ul>
     * <li>{@link #getTargetUserProfiles()} returns a non-empty list for the calling user.</li>
     * <li>The calling app has requested</li>
     * {@code android.Manifest.permission.INTERACT_ACROSS_PROFILES} in its manifest.
     * <li>The calling package has either been whitelisted by default by the OEM or has been
     * explicitly whitelisted by the admin via
     * {@link android.app.admin.DevicePolicyManager#setCrossProfilePackages(ComponentName, Set)}.
     * </li>
     * </ul>
     *
     * @return true if the calling package can request to interact across profiles.
     */
    public boolean canRequestInteractAcrossProfiles() {
        try {
            return mService.canRequestInteractAcrossProfiles(mContext.getPackageName());
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Returns whether the calling package can interact across profiles.
     *
     * <p>The package's current ability to request to interact across profiles can be checked with
     * {@link #canRequestInteractAcrossProfiles()}.
     *
     * <p>Specifically, returns whether the following are all true:
     * <ul>
     * <li>{@link #getTargetUserProfiles()} returns a non-empty list for the calling user.</li>
     * <li>The user has previously consented to cross-profile communication for the calling
     * package.</li>
     * <li>The calling package has either been whitelisted by default by the OEM or has been
     * explicitly whitelisted by the admin via
     * {@link android.app.admin.DevicePolicyManager#setCrossProfilePackages(ComponentName, Set)}.
     * </li>
     * </ul>
     *
     * @return true if the calling package can interact across profiles.
     * @throws SecurityException if {@code mContext.getPackageName()} does not belong to the
     * calling UID.
     */
    public boolean canInteractAcrossProfiles() {
        try {
            return mService.canInteractAcrossProfiles(mContext.getPackageName());
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Returns an {@link Intent} to open the settings page that allows the user to decide whether
     * the calling app can interact across profiles. The current state is given by
     * {@link #canInteractAcrossProfiles()}.
     *
     * <p>Returns {@code null} if {@link #canRequestInteractAcrossProfiles()} is {@code false}.
     *
     * @return an {@link Intent} to open the settings page that allows the user to decide whether
     * the app can interact across profiles
     *
     * @throws SecurityException if {@code mContext.getPackageName()} does not belong to the
     * calling UID.
     */
    public @Nullable Intent createRequestInteractAcrossProfilesIntent() {
        if (!canRequestInteractAcrossProfiles()) {
            return null;
        }
        final Intent settingsIntent = new Intent();
        settingsIntent.setAction(Settings.ACTION_MANAGE_CROSS_PROFILE_ACCESS);
        final Uri packageUri = Uri.parse("package:" + mContext.getPackageName());
        settingsIntent.setData(packageUri);
        return settingsIntent;
    }

    /**
     * Sets the app-op for {@link android.Manifest.permission#INTERACT_ACROSS_PROFILES} that is
     * configurable by users in Settings. This configures it for the profile group of the calling
     * package.
     *
     * <p>Before calling, check {@link #canConfigureInteractAcrossProfiles(String)} and do not call
     * if it is {@code false}. If presenting a user interface, do not allow the user to configure
     * the app-op in that case.
     *
     * <p>The underlying app-op {@link android.app.AppOpsManager#OP_INTERACT_ACROSS_PROFILES} should
     * never be set directly. This method ensures that the app-op is kept in sync for the app across
     * each user in the profile group and that those apps are sent a broadcast when their ability to
     * interact across profiles changes.
     *
     * <p>This method should be used directly whenever a user's action results in a change in an
     * app's ability to interact across profiles, as defined by the return value of {@link
     * #canInteractAcrossProfiles()}. This includes user consent changes in Settings or during
     * provisioning.
     *
     * <p>If other changes could have affected the app's ability to interact across profiles, as
     * defined by the return value of {@link #canInteractAcrossProfiles()}, such as changes to the
     * admin or OEM consent whitelists, then {@link
     * #resetInteractAcrossProfilesAppOpsIfInvalid(List)} should be used.
     *
     * @hide
     */
    @RequiresPermission(
            allOf={android.Manifest.permission.MANAGE_APP_OPS_MODES,
                    android.Manifest.permission.INTERACT_ACROSS_USERS})
    public void setInteractAcrossProfilesAppOp(@NonNull String packageName, @Mode int newMode) {
        try {
            mService.setInteractAcrossProfilesAppOp(packageName, newMode);
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * Returns whether the given package can have its ability to interact across profiles configured
     * by the user. This means that every other condition to interact across profiles has been set.
     *
     * <p>This differs from {@link #canRequestInteractAcrossProfiles()} since it will not return
     * {@code false} simply when the target profile is disabled.
     *
     * @hide
     */
    public boolean canConfigureInteractAcrossProfiles(@NonNull String packageName) {
        try {
            return mService.canConfigureInteractAcrossProfiles(packageName);
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    /**
     * For each of the packages defined in {@code previousCrossProfilePackages} but not included in
     * {@code newCrossProfilePackages}, resets the app-op for {@link android.Manifest.permission
     * #INTERACT_ACROSS_PROFILES} back to its default value if it can no longer be configured by
     * users in Settings, as defined by {@link #canConfigureInteractAcrossProfiles(String)}.
     *
     * <p>This method should be used whenever an app's ability to interact across profiles could
     * have changed as a result of non-user actions, such as changes to admin or OEM consent
     * whitelists.
     *
     * @hide
     */
    @RequiresPermission(
            allOf={android.Manifest.permission.MANAGE_APP_OPS_MODES,
                    android.Manifest.permission.INTERACT_ACROSS_USERS})
    public void resetInteractAcrossProfilesAppOps(
            @NonNull Collection<String> previousCrossProfilePackages,
            @NonNull Set<String> newCrossProfilePackages) {
        if (previousCrossProfilePackages.isEmpty()) {
            return;
        }
        final List<String> unsetCrossProfilePackages =
                previousCrossProfilePackages.stream()
                        .filter(packageName -> !newCrossProfilePackages.contains(packageName))
                        .collect(Collectors.toList());
        if (unsetCrossProfilePackages.isEmpty()) {
            return;
        }
        try {
            mService.resetInteractAcrossProfilesAppOps(unsetCrossProfilePackages);
        } catch (RemoteException ex) {
            throw ex.rethrowFromSystemServer();
        }
    }

    private void verifyCanAccessUser(UserHandle userHandle) {
        if (!getTargetUserProfiles().contains(userHandle)) {
            throw new SecurityException("Not allowed to access " + userHandle);
        }
    }
}