/*
 * 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.RequiresPermission;
import android.annotation.SystemApi;
import android.content.ComponentName;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.os.RemoteException;
import android.os.UserHandle;
import android.os.UserManager;

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

import java.util.List;

/**
 * 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 {
    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(),
                    component,
                    targetUser.getIdentifier(),
                    true);
        } 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(), 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 */);
        }
    }

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