/*
 * Copyright (C) 2010 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.mtp;

import android.content.BroadcastReceiver;
import android.content.ContentProviderClient;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.media.MediaScanner;
import android.net.Uri;
import android.os.BatteryManager;
import android.os.RemoteException;
import android.os.SystemProperties;
import android.os.storage.StorageVolume;
import android.provider.MediaStore;
import android.provider.MediaStore.Audio;
import android.provider.MediaStore.Files;
import android.provider.MediaStore.MediaColumns;
import android.system.ErrnoException;
import android.system.Os;
import android.system.OsConstants;
import android.util.Log;
import android.view.Display;
import android.view.WindowManager;

import dalvik.system.CloseGuard;

import com.google.android.collect.Sets;

import java.io.File;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Locale;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.stream.IntStream;
import java.util.stream.Stream;

MtpDatabase provides an interface for MTP operations that MtpServer can use. To do this, it uses
MtpStorageManager for filesystem operations and MediaProvider to get media metadata. File
operations are also reflected in MediaProvider if possible.
operations
{@hide}
/**
 * MtpDatabase provides an interface for MTP operations that MtpServer can use. To do this, it uses
 * MtpStorageManager for filesystem operations and MediaProvider to get media metadata. File
 * operations are also reflected in MediaProvider if possible.
 * operations
 * {@hide}
 */
public class MtpDatabase implements AutoCloseable {
    private static final String TAG = MtpDatabase.class.getSimpleName();

    private final Context mContext;
    private final ContentProviderClient mMediaProvider;
    private final String mVolumeName;
    private final Uri mObjectsUri;
    private final MediaScanner mMediaScanner;

    private final AtomicBoolean mClosed = new AtomicBoolean();
    private final CloseGuard mCloseGuard = CloseGuard.get();

    private final HashMap<String, MtpStorage> mStorageMap = new HashMap<>();

    // cached property groups for single properties
    private final HashMap<Integer, MtpPropertyGroup> mPropertyGroupsByProperty = new HashMap<>();

    // cached property groups for all properties for a given format
    private final HashMap<Integer, MtpPropertyGroup> mPropertyGroupsByFormat = new HashMap<>();

    // SharedPreferences for writable MTP device properties
    private SharedPreferences mDeviceProperties;

    // Cached device properties
    private int mBatteryLevel;
    private int mBatteryScale;
    private int mDeviceType;

    private MtpServer mServer;
    private MtpStorageManager mManager;

    private static final String PATH_WHERE = Files.FileColumns.DATA + "=?";
    private static final String[] ID_PROJECTION = new String[] {Files.FileColumns._ID};
    private static final String[] PATH_PROJECTION = new String[] {Files.FileColumns.DATA};
    private static final String NO_MEDIA = ".nomedia";

    static {
        System.loadLibrary("media_jni");
    }

    private static final int[] PLAYBACK_FORMATS = {
            // allow transferring arbitrary files
            MtpConstants.FORMAT_UNDEFINED,

            MtpConstants.FORMAT_ASSOCIATION,
            MtpConstants.FORMAT_TEXT,
            MtpConstants.FORMAT_HTML,
            MtpConstants.FORMAT_WAV,
            MtpConstants.FORMAT_MP3,
            MtpConstants.FORMAT_MPEG,
            MtpConstants.FORMAT_EXIF_JPEG,
            MtpConstants.FORMAT_TIFF_EP,
            MtpConstants.FORMAT_BMP,
            MtpConstants.FORMAT_GIF,
            MtpConstants.FORMAT_JFIF,
            MtpConstants.FORMAT_PNG,
            MtpConstants.FORMAT_TIFF,
            MtpConstants.FORMAT_WMA,
            MtpConstants.FORMAT_OGG,
            MtpConstants.FORMAT_AAC,
            MtpConstants.FORMAT_MP4_CONTAINER,
            MtpConstants.FORMAT_MP2,
            MtpConstants.FORMAT_3GP_CONTAINER,
            MtpConstants.FORMAT_ABSTRACT_AV_PLAYLIST,
            MtpConstants.FORMAT_WPL_PLAYLIST,
            MtpConstants.FORMAT_M3U_PLAYLIST,
            MtpConstants.FORMAT_PLS_PLAYLIST,
            MtpConstants.FORMAT_XML_DOCUMENT,
            MtpConstants.FORMAT_FLAC,
            MtpConstants.FORMAT_DNG,
            MtpConstants.FORMAT_HEIF,
    };

    private static final int[] FILE_PROPERTIES = {
            MtpConstants.PROPERTY_STORAGE_ID,
            MtpConstants.PROPERTY_OBJECT_FORMAT,
            MtpConstants.PROPERTY_PROTECTION_STATUS,
            MtpConstants.PROPERTY_OBJECT_SIZE,
            MtpConstants.PROPERTY_OBJECT_FILE_NAME,
            MtpConstants.PROPERTY_DATE_MODIFIED,
            MtpConstants.PROPERTY_PERSISTENT_UID,
            MtpConstants.PROPERTY_PARENT_OBJECT,
            MtpConstants.PROPERTY_NAME,
            MtpConstants.PROPERTY_DISPLAY_NAME,
            MtpConstants.PROPERTY_DATE_ADDED,
    };

    private static final int[] AUDIO_PROPERTIES = {
            MtpConstants.PROPERTY_ARTIST,
            MtpConstants.PROPERTY_ALBUM_NAME,
            MtpConstants.PROPERTY_ALBUM_ARTIST,
            MtpConstants.PROPERTY_TRACK,
            MtpConstants.PROPERTY_ORIGINAL_RELEASE_DATE,
            MtpConstants.PROPERTY_DURATION,
            MtpConstants.PROPERTY_GENRE,
            MtpConstants.PROPERTY_COMPOSER,
            MtpConstants.PROPERTY_AUDIO_WAVE_CODEC,
            MtpConstants.PROPERTY_BITRATE_TYPE,
            MtpConstants.PROPERTY_AUDIO_BITRATE,
            MtpConstants.PROPERTY_NUMBER_OF_CHANNELS,
            MtpConstants.PROPERTY_SAMPLE_RATE,
    };

    private static final int[] VIDEO_PROPERTIES = {
            MtpConstants.PROPERTY_ARTIST,
            MtpConstants.PROPERTY_ALBUM_NAME,
            MtpConstants.PROPERTY_DURATION,
            MtpConstants.PROPERTY_DESCRIPTION,
    };

    private static final int[] IMAGE_PROPERTIES = {
            MtpConstants.PROPERTY_DESCRIPTION,
    };

    private static final int[] DEVICE_PROPERTIES = {
            MtpConstants.DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER,
            MtpConstants.DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME,
            MtpConstants.DEVICE_PROPERTY_IMAGE_SIZE,
            MtpConstants.DEVICE_PROPERTY_BATTERY_LEVEL,
            MtpConstants.DEVICE_PROPERTY_PERCEIVED_DEVICE_TYPE,
    };

    private int[] getSupportedObjectProperties(int format) {
        switch (format) {
            case MtpConstants.FORMAT_MP3:
            case MtpConstants.FORMAT_WAV:
            case MtpConstants.FORMAT_WMA:
            case MtpConstants.FORMAT_OGG:
            case MtpConstants.FORMAT_AAC:
                return IntStream.concat(Arrays.stream(FILE_PROPERTIES),
                        Arrays.stream(AUDIO_PROPERTIES)).toArray();
            case MtpConstants.FORMAT_MPEG:
            case MtpConstants.FORMAT_3GP_CONTAINER:
            case MtpConstants.FORMAT_WMV:
                return IntStream.concat(Arrays.stream(FILE_PROPERTIES),
                        Arrays.stream(VIDEO_PROPERTIES)).toArray();
            case MtpConstants.FORMAT_EXIF_JPEG:
            case MtpConstants.FORMAT_GIF:
            case MtpConstants.FORMAT_PNG:
            case MtpConstants.FORMAT_BMP:
            case MtpConstants.FORMAT_DNG:
            case MtpConstants.FORMAT_HEIF:
                return IntStream.concat(Arrays.stream(FILE_PROPERTIES),
                        Arrays.stream(IMAGE_PROPERTIES)).toArray();
            default:
                return FILE_PROPERTIES;
        }
    }

    private int[] getSupportedDeviceProperties() {
        return DEVICE_PROPERTIES;
    }

    private int[] getSupportedPlaybackFormats() {
        return PLAYBACK_FORMATS;
    }

    private int[] getSupportedCaptureFormats() {
        // no capture formats yet
        return null;
    }

    private BroadcastReceiver mBatteryReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (action.equals(Intent.ACTION_BATTERY_CHANGED)) {
                mBatteryScale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, 0);
                int newLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
                if (newLevel != mBatteryLevel) {
                    mBatteryLevel = newLevel;
                    if (mServer != null) {
                        // send device property changed event
                        mServer.sendDevicePropertyChanged(
                                MtpConstants.DEVICE_PROPERTY_BATTERY_LEVEL);
                    }
                }
            }
        }
    };

    public MtpDatabase(Context context, String volumeName,
            String[] subDirectories) {
        native_setup();
        mContext = context;
        mMediaProvider = context.getContentResolver()
                .acquireContentProviderClient(MediaStore.AUTHORITY);
        mVolumeName = volumeName;
        mObjectsUri = Files.getMtpObjectsUri(volumeName);
        mMediaScanner = new MediaScanner(context, mVolumeName);
        mManager = new MtpStorageManager(new MtpStorageManager.MtpNotifier() {
            @Override
            public void sendObjectAdded(int id) {
                if (MtpDatabase.this.mServer != null)
                    MtpDatabase.this.mServer.sendObjectAdded(id);
            }

            @Override
            public void sendObjectRemoved(int id) {
                if (MtpDatabase.this.mServer != null)
                    MtpDatabase.this.mServer.sendObjectRemoved(id);
            }
        }, subDirectories == null ? null : Sets.newHashSet(subDirectories));

        initDeviceProperties(context);
        mDeviceType = SystemProperties.getInt("sys.usb.mtp.device_type", 0);
        mCloseGuard.open("close");
    }

    public void setServer(MtpServer server) {
        mServer = server;
        // always unregister before registering
        try {
            mContext.unregisterReceiver(mBatteryReceiver);
        } catch (IllegalArgumentException e) {
            // wasn't previously registered, ignore
        }
        // register for battery notifications when we are connected
        if (server != null) {
            mContext.registerReceiver(mBatteryReceiver,
                    new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
        }
    }

    @Override
    public void close() {
        mManager.close();
        mCloseGuard.close();
        if (mClosed.compareAndSet(false, true)) {
            mMediaScanner.close();
            if (mMediaProvider != null) {
                mMediaProvider.close();
            }
            native_finalize();
        }
    }

    @Override
    protected void finalize() throws Throwable {
        try {
            if (mCloseGuard != null) {
                mCloseGuard.warnIfOpen();
            }
            close();
        } finally {
            super.finalize();
        }
    }

    public void addStorage(StorageVolume storage) {
        MtpStorage mtpStorage = mManager.addMtpStorage(storage);
        mStorageMap.put(storage.getPath(), mtpStorage);
        if (mServer != null) {
            mServer.addStorage(mtpStorage);
        }
    }

    public void removeStorage(StorageVolume storage) {
        MtpStorage mtpStorage = mStorageMap.get(storage.getPath());
        if (mtpStorage == null) {
            return;
        }
        if (mServer != null) {
            mServer.removeStorage(mtpStorage);
        }
        mManager.removeMtpStorage(mtpStorage);
        mStorageMap.remove(storage.getPath());
    }

    private void initDeviceProperties(Context context) {
        final String devicePropertiesName = "device-properties";
        mDeviceProperties = context.getSharedPreferences(devicePropertiesName,
                Context.MODE_PRIVATE);
        File databaseFile = context.getDatabasePath(devicePropertiesName);

        if (databaseFile.exists()) {
            // for backward compatibility - read device properties from sqlite database
            // and migrate them to shared prefs
            SQLiteDatabase db = null;
            Cursor c = null;
            try {
                db = context.openOrCreateDatabase("device-properties", Context.MODE_PRIVATE, null);
                if (db != null) {
                    c = db.query("properties", new String[]{"_id", "code", "value"},
                            null, null, null, null, null);
                    if (c != null) {
                        SharedPreferences.Editor e = mDeviceProperties.edit();
                        while (c.moveToNext()) {
                            String name = c.getString(1);
                            String value = c.getString(2);
                            e.putString(name, value);
                        }
                        e.commit();
                    }
                }
            } catch (Exception e) {
                Log.e(TAG, "failed to migrate device properties", e);
            } finally {
                if (c != null) c.close();
                if (db != null) db.close();
            }
            context.deleteDatabase(devicePropertiesName);
        }
    }

    private int beginSendObject(String path, int format, int parent, int storageId) {
        MtpStorageManager.MtpObject parentObj =
                parent == 0 ? mManager.getStorageRoot(storageId) : mManager.getObject(parent);
        if (parentObj == null) {
            return -1;
        }

        Path objPath = Paths.get(path);
        return mManager.beginSendObject(parentObj, objPath.getFileName().toString(), format);
    }

    private void endSendObject(int handle, boolean succeeded) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null || !mManager.endSendObject(obj, succeeded)) {
            Log.e(TAG, "Failed to successfully end send object");
            return;
        }
        // Add the new file to MediaProvider
        if (succeeded) {
            String path = obj.getPath().toString();
            int format = obj.getFormat();
            // Get parent info from MediaProvider, since the id is different from MTP's
            ContentValues values = new ContentValues();
            values.put(Files.FileColumns.DATA, path);
            values.put(Files.FileColumns.FORMAT, format);
            values.put(Files.FileColumns.SIZE, obj.getSize());
            values.put(Files.FileColumns.DATE_MODIFIED, obj.getModifiedTime());
            try {
                if (obj.getParent().isRoot()) {
                    values.put(Files.FileColumns.PARENT, 0);
                } else {
                    int parentId = findInMedia(obj.getParent().getPath());
                    if (parentId != -1) {
                        values.put(Files.FileColumns.PARENT, parentId);
                    } else {
                        // The parent isn't in MediaProvider. Don't add the new file.
                        return;
                    }
                }

                Uri uri = mMediaProvider.insert(mObjectsUri, values);
                if (uri != null) {
                    rescanFile(path, Integer.parseInt(uri.getPathSegments().get(2)), format);
                }
            } catch (RemoteException e) {
                Log.e(TAG, "RemoteException in beginSendObject", e);
            }
        }
    }

    private void rescanFile(String path, int handle, int format) {
        // handle abstract playlists separately
        // they do not exist in the file system so don't use the media scanner here
        if (format == MtpConstants.FORMAT_ABSTRACT_AV_PLAYLIST) {
            // extract name from path
            String name = path;
            int lastSlash = name.lastIndexOf('/');
            if (lastSlash >= 0) {
                name = name.substring(lastSlash + 1);
            }
            // strip trailing ".pla" from the name
            if (name.endsWith(".pla")) {
                name = name.substring(0, name.length() - 4);
            }

            ContentValues values = new ContentValues(1);
            values.put(Audio.Playlists.DATA, path);
            values.put(Audio.Playlists.NAME, name);
            values.put(Files.FileColumns.FORMAT, format);
            values.put(Files.FileColumns.DATE_MODIFIED, System.currentTimeMillis() / 1000);
            values.put(MediaColumns.MEDIA_SCANNER_NEW_OBJECT_ID, handle);
            try {
                mMediaProvider.insert(
                        Audio.Playlists.EXTERNAL_CONTENT_URI, values);
            } catch (RemoteException e) {
                Log.e(TAG, "RemoteException in endSendObject", e);
            }
        } else {
            mMediaScanner.scanMtpFile(path, handle, format);
        }
    }

    private int[] getObjectList(int storageID, int format, int parent) {
        Stream<MtpStorageManager.MtpObject> objectStream = mManager.getObjects(parent,
                format, storageID);
        if (objectStream == null) {
            return null;
        }
        return objectStream.mapToInt(MtpStorageManager.MtpObject::getId).toArray();
    }

    private int getNumObjects(int storageID, int format, int parent) {
        Stream<MtpStorageManager.MtpObject> objectStream = mManager.getObjects(parent,
                format, storageID);
        if (objectStream == null) {
            return -1;
        }
        return (int) objectStream.count();
    }

    private MtpPropertyList getObjectPropertyList(int handle, int format, int property,
            int groupCode, int depth) {
        // FIXME - implement group support
        if (property == 0) {
            if (groupCode == 0) {
                return new MtpPropertyList(MtpConstants.RESPONSE_PARAMETER_NOT_SUPPORTED);
            }
            return new MtpPropertyList(MtpConstants.RESPONSE_SPECIFICATION_BY_GROUP_UNSUPPORTED);
        }
        if (depth == 0xFFFFFFFF && (handle == 0 || handle == 0xFFFFFFFF)) {
            // request all objects starting at root
            handle = 0xFFFFFFFF;
            depth = 0;
        }
        if (!(depth == 0 || depth == 1)) {
            // we only support depth 0 and 1
            // depth 0: single object, depth 1: immediate children
            return new MtpPropertyList(MtpConstants.RESPONSE_SPECIFICATION_BY_DEPTH_UNSUPPORTED);
        }
        Stream<MtpStorageManager.MtpObject> objectStream = Stream.of();
        if (handle == 0xFFFFFFFF) {
            // All objects are requested
            objectStream = mManager.getObjects(0, format, 0xFFFFFFFF);
            if (objectStream == null) {
                return new MtpPropertyList(MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE);
            }
        } else if (handle != 0) {
            // Add the requested object if format matches
            MtpStorageManager.MtpObject obj = mManager.getObject(handle);
            if (obj == null) {
                return new MtpPropertyList(MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE);
            }
            if (obj.getFormat() == format || format == 0) {
                objectStream = Stream.of(obj);
            }
        }
        if (handle == 0 || depth == 1) {
            if (handle == 0) {
                handle = 0xFFFFFFFF;
            }
            // Get the direct children of root or this object.
            Stream<MtpStorageManager.MtpObject> childStream = mManager.getObjects(handle, format,
                    0xFFFFFFFF);
            if (childStream == null) {
                return new MtpPropertyList(MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE);
            }
            objectStream = Stream.concat(objectStream, childStream);
        }

        MtpPropertyList ret = new MtpPropertyList(MtpConstants.RESPONSE_OK);
        MtpPropertyGroup propertyGroup;
        Iterator<MtpStorageManager.MtpObject> iter = objectStream.iterator();
        while (iter.hasNext()) {
            MtpStorageManager.MtpObject obj = iter.next();
            if (property == 0xffffffff) {
                // Get all properties supported by this object
                propertyGroup = mPropertyGroupsByFormat.get(obj.getFormat());
                if (propertyGroup == null) {
                    int[] propertyList = getSupportedObjectProperties(format);
                    propertyGroup = new MtpPropertyGroup(mMediaProvider, mVolumeName,
                            propertyList);
                    mPropertyGroupsByFormat.put(format, propertyGroup);
                }
            } else {
                // Get this property value
                final int[] propertyList = new int[]{property};
                propertyGroup = mPropertyGroupsByProperty.get(property);
                if (propertyGroup == null) {
                    propertyGroup = new MtpPropertyGroup(mMediaProvider, mVolumeName,
                            propertyList);
                    mPropertyGroupsByProperty.put(property, propertyGroup);
                }
            }
            int err = propertyGroup.getPropertyList(obj, ret);
            if (err != MtpConstants.RESPONSE_OK) {
                return new MtpPropertyList(err);
            }
        }
        return ret;
    }

    private int renameFile(int handle, String newName) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null) {
            return MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE;
        }
        Path oldPath = obj.getPath();

        // now rename the file.  make sure this succeeds before updating database
        if (!mManager.beginRenameObject(obj, newName))
            return MtpConstants.RESPONSE_GENERAL_ERROR;
        Path newPath = obj.getPath();
        boolean success = oldPath.toFile().renameTo(newPath.toFile());
        try {
            Os.access(oldPath.toString(), OsConstants.F_OK);
            Os.access(newPath.toString(), OsConstants.F_OK);
        } catch (ErrnoException e) {
            // Ignore. Could fail if the metadata was already updated.
        }

        if (!mManager.endRenameObject(obj, oldPath.getFileName().toString(), success)) {
            Log.e(TAG, "Failed to end rename object");
        }
        if (!success) {
            return MtpConstants.RESPONSE_GENERAL_ERROR;
        }

        // finally update MediaProvider
        ContentValues values = new ContentValues();
        values.put(Files.FileColumns.DATA, newPath.toString());
        String[] whereArgs = new String[]{oldPath.toString()};
        try {
            // note - we are relying on a special case in MediaProvider.update() to update
            // the paths for all children in the case where this is a directory.
            mMediaProvider.update(mObjectsUri, values, PATH_WHERE, whereArgs);
        } catch (RemoteException e) {
            Log.e(TAG, "RemoteException in mMediaProvider.update", e);
        }

        // check if nomedia status changed
        if (obj.isDir()) {
            // for directories, check if renamed from something hidden to something non-hidden
            if (oldPath.getFileName().startsWith(".") && !newPath.startsWith(".")) {
                // directory was unhidden
                try {
                    mMediaProvider.call(MediaStore.UNHIDE_CALL, newPath.toString(), null);
                } catch (RemoteException e) {
                    Log.e(TAG, "failed to unhide/rescan for " + newPath);
                }
            }
        } else {
            // for files, check if renamed from .nomedia to something else
            if (oldPath.getFileName().toString().toLowerCase(Locale.US).equals(NO_MEDIA)
                    && !newPath.getFileName().toString().toLowerCase(Locale.US).equals(NO_MEDIA)) {
                try {
                    mMediaProvider.call(MediaStore.UNHIDE_CALL,
                            oldPath.getParent().toString(), null);
                } catch (RemoteException e) {
                    Log.e(TAG, "failed to unhide/rescan for " + newPath);
                }
            }
        }
        return MtpConstants.RESPONSE_OK;
    }

    private int beginMoveObject(int handle, int newParent, int newStorage) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        MtpStorageManager.MtpObject parent = newParent == 0 ?
                mManager.getStorageRoot(newStorage) : mManager.getObject(newParent);
        if (obj == null || parent == null)
            return MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE;

        boolean allowed = mManager.beginMoveObject(obj, parent);
        return allowed ? MtpConstants.RESPONSE_OK : MtpConstants.RESPONSE_GENERAL_ERROR;
    }

    private void endMoveObject(int oldParent, int newParent, int oldStorage, int newStorage,
            int objId, boolean success) {
        MtpStorageManager.MtpObject oldParentObj = oldParent == 0 ?
                mManager.getStorageRoot(oldStorage) : mManager.getObject(oldParent);
        MtpStorageManager.MtpObject newParentObj = newParent == 0 ?
                mManager.getStorageRoot(newStorage) : mManager.getObject(newParent);
        MtpStorageManager.MtpObject obj = mManager.getObject(objId);
        String name = obj.getName();
        if (newParentObj == null || oldParentObj == null
                ||!mManager.endMoveObject(oldParentObj, newParentObj, name, success)) {
            Log.e(TAG, "Failed to end move object");
            return;
        }

        obj = mManager.getObject(objId);
        if (!success || obj == null)
            return;
        // Get parent info from MediaProvider, since the id is different from MTP's
        ContentValues values = new ContentValues();
        Path path = newParentObj.getPath().resolve(name);
        Path oldPath = oldParentObj.getPath().resolve(name);
        values.put(Files.FileColumns.DATA, path.toString());
        if (obj.getParent().isRoot()) {
            values.put(Files.FileColumns.PARENT, 0);
        } else {
            int parentId = findInMedia(path.getParent());
            if (parentId != -1) {
                values.put(Files.FileColumns.PARENT, parentId);
            } else {
                // The new parent isn't in MediaProvider, so delete the object instead
                deleteFromMedia(oldPath, obj.isDir());
                return;
            }
        }
        // update MediaProvider
        Cursor c = null;
        String[] whereArgs = new String[]{oldPath.toString()};
        try {
            int parentId = -1;
            if (!oldParentObj.isRoot()) {
                parentId = findInMedia(oldPath.getParent());
            }
            if (oldParentObj.isRoot() || parentId != -1) {
                // Old parent exists in MediaProvider - perform a move
                // note - we are relying on a special case in MediaProvider.update() to update
                // the paths for all children in the case where this is a directory.
                mMediaProvider.update(mObjectsUri, values, PATH_WHERE, whereArgs);
            } else {
                // Old parent doesn't exist - add the object
                values.put(Files.FileColumns.FORMAT, obj.getFormat());
                values.put(Files.FileColumns.SIZE, obj.getSize());
                values.put(Files.FileColumns.DATE_MODIFIED, obj.getModifiedTime());
                Uri uri = mMediaProvider.insert(mObjectsUri, values);
                if (uri != null) {
                    rescanFile(path.toString(),
                            Integer.parseInt(uri.getPathSegments().get(2)), obj.getFormat());
                }
            }
        } catch (RemoteException e) {
            Log.e(TAG, "RemoteException in mMediaProvider.update", e);
        }
    }

    private int beginCopyObject(int handle, int newParent, int newStorage) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        MtpStorageManager.MtpObject parent = newParent == 0 ?
                mManager.getStorageRoot(newStorage) : mManager.getObject(newParent);
        if (obj == null || parent == null)
            return MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE;
        return mManager.beginCopyObject(obj, parent);
    }

    private void endCopyObject(int handle, boolean success) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null || !mManager.endCopyObject(obj, success)) {
            Log.e(TAG, "Failed to end copy object");
            return;
        }
        if (!success) {
            return;
        }
        String path = obj.getPath().toString();
        int format = obj.getFormat();
        // Get parent info from MediaProvider, since the id is different from MTP's
        ContentValues values = new ContentValues();
        values.put(Files.FileColumns.DATA, path);
        values.put(Files.FileColumns.FORMAT, format);
        values.put(Files.FileColumns.SIZE, obj.getSize());
        values.put(Files.FileColumns.DATE_MODIFIED, obj.getModifiedTime());
        try {
            if (obj.getParent().isRoot()) {
                values.put(Files.FileColumns.PARENT, 0);
            } else {
                int parentId = findInMedia(obj.getParent().getPath());
                if (parentId != -1) {
                    values.put(Files.FileColumns.PARENT, parentId);
                } else {
                    // The parent isn't in MediaProvider. Don't add the new file.
                    return;
                }
            }
            if (obj.isDir()) {
                mMediaScanner.scanDirectories(new String[]{path});
            } else {
                Uri uri = mMediaProvider.insert(mObjectsUri, values);
                if (uri != null) {
                    rescanFile(path, Integer.parseInt(uri.getPathSegments().get(2)), format);
                }
            }
        } catch (RemoteException e) {
            Log.e(TAG, "RemoteException in beginSendObject", e);
        }
    }

    private int setObjectProperty(int handle, int property,
            long intValue, String stringValue) {
        switch (property) {
            case MtpConstants.PROPERTY_OBJECT_FILE_NAME:
                return renameFile(handle, stringValue);

            default:
                return MtpConstants.RESPONSE_OBJECT_PROP_NOT_SUPPORTED;
        }
    }

    private int getDeviceProperty(int property, long[] outIntValue, char[] outStringValue) {
        switch (property) {
            case MtpConstants.DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER:
            case MtpConstants.DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME:
                // writable string properties kept in shared preferences
                String value = mDeviceProperties.getString(Integer.toString(property), "");
                int length = value.length();
                if (length > 255) {
                    length = 255;
                }
                value.getChars(0, length, outStringValue, 0);
                outStringValue[length] = 0;
                return MtpConstants.RESPONSE_OK;
            case MtpConstants.DEVICE_PROPERTY_IMAGE_SIZE:
                // use screen size as max image size
                Display display = ((WindowManager) mContext.getSystemService(
                        Context.WINDOW_SERVICE)).getDefaultDisplay();
                int width = display.getMaximumSizeDimension();
                int height = display.getMaximumSizeDimension();
                String imageSize = Integer.toString(width) + "x" + Integer.toString(height);
                imageSize.getChars(0, imageSize.length(), outStringValue, 0);
                outStringValue[imageSize.length()] = 0;
                return MtpConstants.RESPONSE_OK;
            case MtpConstants.DEVICE_PROPERTY_PERCEIVED_DEVICE_TYPE:
                outIntValue[0] = mDeviceType;
                return MtpConstants.RESPONSE_OK;
            case MtpConstants.DEVICE_PROPERTY_BATTERY_LEVEL:
                outIntValue[0] = mBatteryLevel;
                outIntValue[1] = mBatteryScale;
                return MtpConstants.RESPONSE_OK;
            default:
                return MtpConstants.RESPONSE_DEVICE_PROP_NOT_SUPPORTED;
        }
    }

    private int setDeviceProperty(int property, long intValue, String stringValue) {
        switch (property) {
            case MtpConstants.DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER:
            case MtpConstants.DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME:
                // writable string properties kept in shared prefs
                SharedPreferences.Editor e = mDeviceProperties.edit();
                e.putString(Integer.toString(property), stringValue);
                return (e.commit() ? MtpConstants.RESPONSE_OK
                        : MtpConstants.RESPONSE_GENERAL_ERROR);
        }

        return MtpConstants.RESPONSE_DEVICE_PROP_NOT_SUPPORTED;
    }

    private boolean getObjectInfo(int handle, int[] outStorageFormatParent,
            char[] outName, long[] outCreatedModified) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null) {
            return false;
        }
        outStorageFormatParent[0] = obj.getStorageId();
        outStorageFormatParent[1] = obj.getFormat();
        outStorageFormatParent[2] = obj.getParent().isRoot() ? 0 : obj.getParent().getId();

        int nameLen = Integer.min(obj.getName().length(), 255);
        obj.getName().getChars(0, nameLen, outName, 0);
        outName[nameLen] = 0;

        outCreatedModified[0] = obj.getModifiedTime();
        outCreatedModified[1] = obj.getModifiedTime();
        return true;
    }

    private int getObjectFilePath(int handle, char[] outFilePath, long[] outFileLengthFormat) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null) {
            return MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE;
        }

        String path = obj.getPath().toString();
        int pathLen = Integer.min(path.length(), 4096);
        path.getChars(0, pathLen, outFilePath, 0);
        outFilePath[pathLen] = 0;

        outFileLengthFormat[0] = obj.getSize();
        outFileLengthFormat[1] = obj.getFormat();
        return MtpConstants.RESPONSE_OK;
    }

    private int getObjectFormat(int handle) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null) {
            return -1;
        }
        return obj.getFormat();
    }

    private int beginDeleteObject(int handle) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null) {
            return MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE;
        }
        if (!mManager.beginRemoveObject(obj)) {
            return MtpConstants.RESPONSE_GENERAL_ERROR;
        }
        return MtpConstants.RESPONSE_OK;
    }

    private void endDeleteObject(int handle, boolean success) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null) {
            return;
        }
        if (!mManager.endRemoveObject(obj, success))
            Log.e(TAG, "Failed to end remove object");
        if (success)
            deleteFromMedia(obj.getPath(), obj.isDir());
    }

    private int findInMedia(Path path) {
        int ret = -1;
        Cursor c = null;
        try {
            c = mMediaProvider.query(mObjectsUri, ID_PROJECTION, PATH_WHERE,
                    new String[]{path.toString()}, null, null);
            if (c != null && c.moveToNext()) {
                ret = c.getInt(0);
            }
        } catch (RemoteException e) {
            Log.e(TAG, "Error finding " + path + " in MediaProvider");
        } finally {
            if (c != null)
                c.close();
        }
        return ret;
    }

    private void deleteFromMedia(Path path, boolean isDir) {
        try {
            // Delete the object(s) from MediaProvider, but ignore errors.
            if (isDir) {
                // recursive case - delete all children first
                mMediaProvider.delete(mObjectsUri,
                        // the 'like' makes it use the index, the 'lower()' makes it correct
                        // when the path contains sqlite wildcard characters
                        "_data LIKE ?1 AND lower(substr(_data,1,?2))=lower(?3)",
                        new String[]{path + "/%", Integer.toString(path.toString().length() + 1),
                                path.toString() + "/"});
            }

            String[] whereArgs = new String[]{path.toString()};
            if (mMediaProvider.delete(mObjectsUri, PATH_WHERE, whereArgs) > 0) {
                if (!isDir && path.toString().toLowerCase(Locale.US).endsWith(NO_MEDIA)) {
                    try {
                        String parentPath = path.getParent().toString();
                        mMediaProvider.call(MediaStore.UNHIDE_CALL, parentPath, null);
                    } catch (RemoteException e) {
                        Log.e(TAG, "failed to unhide/rescan for " + path);
                    }
                }
            } else {
                Log.i(TAG, "Mediaprovider didn't delete " + path);
            }
        } catch (Exception e) {
            Log.d(TAG, "Failed to delete " + path + " from MediaProvider");
        }
    }

    private int[] getObjectReferences(int handle) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null)
            return null;
        // Translate this handle to the MediaProvider Handle
        handle = findInMedia(obj.getPath());
        if (handle == -1)
            return null;
        Uri uri = Files.getMtpReferencesUri(mVolumeName, handle);
        Cursor c = null;
        try {
            c = mMediaProvider.query(uri, PATH_PROJECTION, null, null, null, null);
            if (c == null) {
                return null;
            }
                ArrayList<Integer> result = new ArrayList<>();
                while (c.moveToNext()) {
                    // Translate result handles back into handles for this session.
                    String refPath = c.getString(0);
                    MtpStorageManager.MtpObject refObj = mManager.getByPath(refPath);
                    if (refObj != null) {
                        result.add(refObj.getId());
                    }
                }
                return result.stream().mapToInt(Integer::intValue).toArray();
        } catch (RemoteException e) {
            Log.e(TAG, "RemoteException in getObjectList", e);
        } finally {
            if (c != null) {
                c.close();
            }
        }
        return null;
    }

    private int setObjectReferences(int handle, int[] references) {
        MtpStorageManager.MtpObject obj = mManager.getObject(handle);
        if (obj == null)
            return MtpConstants.RESPONSE_INVALID_OBJECT_HANDLE;
        // Translate this handle to the MediaProvider Handle
        handle = findInMedia(obj.getPath());
        if (handle == -1)
            return MtpConstants.RESPONSE_GENERAL_ERROR;
        Uri uri = Files.getMtpReferencesUri(mVolumeName, handle);
        ArrayList<ContentValues> valuesList = new ArrayList<>();
        for (int id : references) {
            // Translate each reference id to the MediaProvider Id
            MtpStorageManager.MtpObject refObj = mManager.getObject(id);
            if (refObj == null)
                continue;
            int refHandle = findInMedia(refObj.getPath());
            if (refHandle == -1)
                continue;
            ContentValues values = new ContentValues();
            values.put(Files.FileColumns._ID, refHandle);
            valuesList.add(values);
        }
        try {
            if (mMediaProvider.bulkInsert(uri, valuesList.toArray(new ContentValues[0])) > 0) {
                return MtpConstants.RESPONSE_OK;
            }
        } catch (RemoteException e) {
            Log.e(TAG, "RemoteException in setObjectReferences", e);
        }
        return MtpConstants.RESPONSE_GENERAL_ERROR;
    }

    // used by the JNI code
    private long mNativeContext;

    private native final void native_setup();
    private native final void native_finalize();
}