/*
 * Copyright (C) 2016 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.server.usb;

import android.annotation.NonNull;
import android.annotation.UserIdInt;
import android.content.Context;
import android.content.pm.UserInfo;
import android.os.UserHandle;
import android.os.UserManager;
import android.service.usb.UsbSettingsManagerProto;
import android.util.SparseArray;

import com.android.internal.annotations.GuardedBy;
import com.android.internal.util.dump.DualDumpOutputStream;

import java.util.List;

/**
 * Maintains all {@link UsbUserSettingsManager} for all users.
 */
class UsbSettingsManager {
    private static final String LOG_TAG = UsbSettingsManager.class.getSimpleName();
    private static final boolean DEBUG = false;

    /** Context to be used by this module */
    private final @NonNull Context mContext;

    /** Map from user id to {@link UsbUserSettingsManager} for the user */
    @GuardedBy("mSettingsByUser")
    private final SparseArray<UsbUserSettingsManager> mSettingsByUser = new SparseArray<>();

    /**
     * Map from the parent profile's user id to {@link UsbProfileGroupSettingsManager} for the
     * group.
     */
    @GuardedBy("mSettingsByProfileGroup")
    private final SparseArray<UsbProfileGroupSettingsManager> mSettingsByProfileGroup
            = new SparseArray<>();
    private UserManager mUserManager;
    private UsbHandlerManager mUsbHandlerManager;

    final UsbService mUsbService;

    UsbSettingsManager(@NonNull Context context, UsbService usbService) {
        mContext = context;
        mUsbService = usbService;
        mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
        mUsbHandlerManager = new UsbHandlerManager(context);
    }

    /**
     * Get the {@link UsbUserSettingsManager} for a user.
     *
     * @param userId The id of the user
     *
     * @return The settings for the user
     */
    @NonNull UsbUserSettingsManager getSettingsForUser(@UserIdInt int userId) {
        synchronized (mSettingsByUser) {
            UsbUserSettingsManager settings = mSettingsByUser.get(userId);
            if (settings == null) {
                settings = new UsbUserSettingsManager(mContext, UserHandle.of(userId));
                mSettingsByUser.put(userId, settings);
            }
            return settings;
        }
    }

    /**
     * Get the {@link UsbProfileGroupSettingsManager} for a user.
     *
     * @param user Any user of the profile group
     *
     * @return The settings for the profile group
     */
    @NonNull UsbProfileGroupSettingsManager getSettingsForProfileGroup(@NonNull UserHandle user) {
        UserHandle parentUser;

        UserInfo parentUserInfo = mUserManager.getProfileParent(user.getIdentifier());
        if (parentUserInfo != null) {
            parentUser = parentUserInfo.getUserHandle();
        } else {
            parentUser = user;
        }

        synchronized (mSettingsByProfileGroup) {
            UsbProfileGroupSettingsManager settings = mSettingsByProfileGroup.get(
                    parentUser.getIdentifier());
            if (settings == null) {
                settings = new UsbProfileGroupSettingsManager(mContext, parentUser, this,
                      mUsbHandlerManager);
                mSettingsByProfileGroup.put(parentUser.getIdentifier(), settings);
            }
            return settings;
        }
    }

    /**
     * Remove the settings for a user.
     *
     * @param userToRemove The user to remove
     */
    void remove(@NonNull UserHandle userToRemove) {
        synchronized (mSettingsByUser) {
            mSettingsByUser.remove(userToRemove.getIdentifier());
        }

        synchronized (mSettingsByProfileGroup) {
            if (mSettingsByProfileGroup.indexOfKey(userToRemove.getIdentifier()) >= 0) {
                // The user to remove is the parent user of the group. The parent is the last user
                // that gets removed. All state will be removed with the user
                mSettingsByProfileGroup.get(userToRemove.getIdentifier()).unregisterReceivers();
                mSettingsByProfileGroup.remove(userToRemove.getIdentifier());
            } else {
                // We cannot find the parent user of the user that is removed, hence try to remove
                // it from all profile groups.
                int numProfileGroups = mSettingsByProfileGroup.size();
                for (int i = 0; i < numProfileGroups; i++) {
                    mSettingsByProfileGroup.valueAt(i).removeUser(userToRemove);
                }
            }
        }
    }

    /**
     * Dump all settings of all users.
     */
    void dump(@NonNull DualDumpOutputStream dump, String idName, long id) {
        long token = dump.start(idName, id);

        synchronized (mSettingsByUser) {
            List<UserInfo> users = mUserManager.getUsers();
            int numUsers = users.size();
            for (int i = 0; i < numUsers; i++) {
                getSettingsForUser(users.get(i).id).dump(dump, "user_settings",
                        UsbSettingsManagerProto.USER_SETTINGS);
            }
        }

        synchronized (mSettingsByProfileGroup) {
            int numProfileGroups = mSettingsByProfileGroup.size();
            for (int i = 0; i < numProfileGroups; i++) {
                mSettingsByProfileGroup.valueAt(i).dump(dump, "profile_group_settings",
                        UsbSettingsManagerProto.PROFILE_GROUP_SETTINGS);
            }
        }

        dump.end(token);
    }
}