Handle changes in call metadata and trigger syncs

/*

 * 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.server.companion;

import android.provider.DeviceConfig;

/**

 * Feature flags for companion.

 */

public class CompanionDeviceConfig {

    private static final String NAMESPACE_COMPANION = "companion";

    /**

     * Whether system data syncing for telecom-type data is enabled.

     */

    public static final String ENABLE_CONTEXT_SYNC_TELECOM = "enable_context_sync_telecom";

    /**

     * Returns whether the given flag is currently enabled, with a default value of {@code true}.

     */

    public static boolean isEnabled(String flag) {

        return DeviceConfig.getBoolean(NAMESPACE_COMPANION, flag, /* defaultValue= */ true);

    }

    /**

     * Returns whether the given flag is currently enabled.

     */

    public static boolean isEnabled(String flag, boolean defaultValue) {

        return DeviceConfig.getBoolean(NAMESPACE_COMPANION, flag, defaultValue);

    }

}

/*

 * 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.server.companion.datatransfer.contextsync;

import android.app.admin.DevicePolicyManager;

import android.companion.AssociationInfo;

import android.companion.ContextSyncMessage;

import android.companion.Telecom;

import android.companion.Telecom.Call;

import android.content.Context;

import android.os.UserHandle;

import android.util.Pair;

import android.util.Slog;

import android.util.proto.ProtoOutputStream;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.util.Collection;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

/**

 * Monitors connections and sending / receiving of synced data.

 */

public class CrossDeviceSyncController {

    private static final String TAG = "CrossDeviceSyncController";

    private static final int BYTE_ARRAY_SIZE = 64;

    private final Context mContext;

    private final Callback mCdmCallback;

    private final Map<Integer, List<AssociationInfo>> mUserIdToAssociationInfo = new HashMap<>();

    private final Map<Integer, Pair<InputStream, OutputStream>> mAssociationIdToStreams =

            new HashMap<>();

    private final Set<Integer> mBlocklist = new HashSet<>();

    private CallMetadataSyncCallback mInCallServiceCallMetadataSyncCallback;

    public CrossDeviceSyncController(Context context, Callback callback) {

        mContext = context;

        mCdmCallback = callback;

    }

    /** Registers the call metadata callback. */

    public void registerCallMetadataSyncCallback(CallMetadataSyncCallback callback) {

        mInCallServiceCallMetadataSyncCallback = callback;

    }

    /** Allow specific associated devices to enable / disable syncing. */

    public void setSyncEnabled(AssociationInfo associationInfo, boolean enabled) {

        if (enabled) {

            if (mBlocklist.contains(associationInfo.getId())) {

                mBlocklist.remove(associationInfo.getId());

                openChannel(associationInfo);

            }

        } else {

            if (!mBlocklist.contains(associationInfo.getId())) {

                mBlocklist.add(associationInfo.getId());

                closeChannel(associationInfo);

            }

        }

    }

    /**

     * Opens channels to newly associated devices, and closes channels to newly disassociated

     * devices.

     *

     * TODO(b/265466098): this needs to be limited to just connected devices

     */

    public void onAssociationsChanged(int userId, List<AssociationInfo> newAssociationInfoList) {

        final List<AssociationInfo> existingAssociationInfoList = mUserIdToAssociationInfo.get(

                userId);

        // Close channels to newly-disconnected devices.

        for (AssociationInfo existingAssociationInfo : existingAssociationInfoList) {

            if (!newAssociationInfoList.contains(existingAssociationInfo) && !mBlocklist.contains(

                    existingAssociationInfo.getId())) {

                closeChannel(existingAssociationInfo);

            }

        }

        // Open channels to newly-connected devices.

        for (AssociationInfo newAssociationInfo : newAssociationInfoList) {

            if (!existingAssociationInfoList.contains(newAssociationInfo) && !mBlocklist.contains(

                    newAssociationInfo.getId())) {

                openChannel(newAssociationInfo);

            }

        }

        mUserIdToAssociationInfo.put(userId, newAssociationInfoList);

    }

    private boolean isAdminBlocked(int userId) {

        return mContext.getSystemService(DevicePolicyManager.class)

                .getBluetoothContactSharingDisabled(UserHandle.of(userId));

    }

    /** Stop reading, close streams, and close secure channel. */

    private void closeChannel(AssociationInfo associationInfo) {

        // TODO(b/265466098): stop reading from secure channel

        final Pair<InputStream, OutputStream> streams = mAssociationIdToStreams.get(

                associationInfo.getId());

        if (streams != null) {

            try {

                if (streams.first != null) {

                    streams.first.close();

                }

                if (streams.second != null) {

                    streams.second.close();

                }

            } catch (IOException e) {

                Slog.e(TAG, "Could not close streams for association " + associationInfo.getId(),

                        e);

            }

        }

        mCdmCallback.closeSecureChannel(associationInfo.getId());

    }

    /** Sync initial snapshot and start reading. */

    private void openChannel(AssociationInfo associationInfo) {

        final InputStream is = new ByteArrayInputStream(new byte[BYTE_ARRAY_SIZE]);

        final OutputStream os = new ByteArrayOutputStream(BYTE_ARRAY_SIZE);

        mAssociationIdToStreams.put(associationInfo.getId(), new Pair<>(is, os));

        mCdmCallback.createSecureChannel(associationInfo.getId(), is, os);

        // TODO(b/265466098): only requestSync for this specific association / connection?

        mInCallServiceCallMetadataSyncCallback.requestCrossDeviceSync(associationInfo.getUserId());

        // TODO(b/265466098): start reading from secure channel

    }

    /**

     * Sync data to associated devices.

     *

     * @param userId The user whose data should be synced.

     * @param calls The full list of current calls for all users.

     */

    public void crossDeviceSync(int userId, Collection<CrossDeviceCall> calls) {

        final boolean isAdminBlocked = isAdminBlocked(userId);

        for (AssociationInfo associationInfo : mUserIdToAssociationInfo.get(userId)) {

            final Pair<InputStream, OutputStream> streams = mAssociationIdToStreams.get(

                    associationInfo.getId());

            final ProtoOutputStream pos = new ProtoOutputStream(streams.second);

            final long telecomToken = pos.start(ContextSyncMessage.TELECOM);

            for (CrossDeviceCall call : calls) {

                final long callsToken = pos.start(Telecom.CALLS);

                pos.write(Call.ID, call.getId());

                final long originToken = pos.start(Call.ORIGIN);

                pos.write(Call.Origin.CALLER_ID, call.getReadableCallerId(isAdminBlocked));

                pos.write(Call.Origin.APP_ICON, call.getCallingAppIcon());

                pos.write(Call.Origin.APP_NAME, call.getCallingAppName());

                pos.end(originToken);

                pos.write(Call.STATUS, call.getStatus());

                for (int control : call.getControls()) {

                    pos.write(Call.CONTROLS_AVAILABLE, control);

                }

                pos.end(callsToken);

            }

            pos.end(telecomToken);

            pos.flush();

        }

    }

    /**

     * Callback to be implemented by CompanionDeviceManagerService.

     */

    public interface Callback {

        /**

         * Create a secure channel to send messages.

         */

        void createSecureChannel(int associationId, InputStream input, OutputStream output);

        /**

         * Close the secure channel created previously.

         */

        void closeSecureChannel(int associationId);

    }

}