package eu.siacs.conversations.persistance;

import android.annotation.TargetApi;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.RectF;
import android.media.MediaMetadataRetriever;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.os.ParcelFileDescriptor;
import android.provider.MediaStore;
import android.provider.OpenableColumns;
import android.support.v4.content.FileProvider;
import android.system.Os;
import android.system.StructStat;
import android.util.Base64;
import android.util.Base64OutputStream;
import android.util.Log;
import android.util.LruCache;
import android.webkit.MimeTypeMap;

import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.URL;
import java.security.DigestOutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.UUID;

import eu.siacs.conversations.Config;
import eu.siacs.conversations.R;
import eu.siacs.conversations.entities.DownloadableFile;
import eu.siacs.conversations.entities.Message;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.ui.RecordingActivity;
import eu.siacs.conversations.utils.CryptoHelper;
import eu.siacs.conversations.utils.ExifHelper;
import eu.siacs.conversations.utils.FileUtils;
import eu.siacs.conversations.utils.FileWriterException;
import eu.siacs.conversations.utils.MimeUtils;
import eu.siacs.conversations.xmpp.pep.Avatar;

public class FileBackend {

	private static final Object THUMBNAIL_LOCK = new Object();

	private static final SimpleDateFormat IMAGE_DATE_FORMAT = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US);

	private static final String FILE_PROVIDER = ".files";

	private XmppConnectionService mXmppConnectionService;

	public FileBackend(XmppConnectionService service) {
		this.mXmppConnectionService = service;
	}

	private static boolean isInDirectoryThatShouldNotBeScanned(Context context, File file) {
		return isInDirectoryThatShouldNotBeScanned(context, file.getAbsolutePath());
	}

	public static boolean isInDirectoryThatShouldNotBeScanned(Context context, String path) {
		for (String type : new String[]{RecordingActivity.STORAGE_DIRECTORY_TYPE_NAME, "Files"}) {
			if (path.startsWith(getConversationsDirectory(context, type))) {
				return true;
			}
		}
		return false;
	}

	public static long getFileSize(Context context, Uri uri) {
		try {
			final Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
			if (cursor != null && cursor.moveToFirst()) {
				long size = cursor.getLong(cursor.getColumnIndex(OpenableColumns.SIZE));
				cursor.close();
				return size;
			} else {
				return -1;
			}
		} catch (Exception e) {
			return -1;
		}
	}

	public static boolean allFilesUnderSize(Context context, List<Uri> uris, long max) {
		if (max <= 0) {
			Log.d(Config.LOGTAG, "server did not report max file size for http upload");
			return true; //exception to be compatible with HTTP Upload < v0.2
		}
		for (Uri uri : uris) {
			String mime = context.getContentResolver().getType(uri);
			if (mime != null && mime.startsWith("video/")) {
				try {
					Dimensions dimensions = FileBackend.getVideoDimensions(context, uri);
					if (dimensions.getMin() > 720) {
						Log.d(Config.LOGTAG, "do not consider video file with min width larger than 720 for size check");
						continue;
					}
				} catch (NotAVideoFile notAVideoFile) {
					//ignore and fall through
				}
			}
			if (FileBackend.getFileSize(context, uri) > max) {
				Log.d(Config.LOGTAG, "not all files are under " + max + " bytes. suggesting falling back to jingle");
				return false;
			}
		}
		return true;
	}

	public static String getConversationsDirectory(Context context, final String type) {
		if (Config.ONLY_INTERNAL_STORAGE) {
			return context.getFilesDir().getAbsolutePath() + "/" + type + "/";
		} else {
			return getAppMediaDirectory(context) + context.getString(R.string.app_name) + " " + type + "/";
		}
	}

	public static String getAppMediaDirectory(Context context) {
		return Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + context.getString(R.string.app_name) + "/Media/";
	}

	public static String getConversationsLogsDirectory() {
		return Environment.getExternalStorageDirectory().getAbsolutePath() + "/Conversations/";
	}

	private static Bitmap rotate(Bitmap bitmap, int degree) {
		if (degree == 0) {
			return bitmap;
		}
		int w = bitmap.getWidth();
		int h = bitmap.getHeight();
		Matrix mtx = new Matrix();
		mtx.postRotate(degree);
		Bitmap result = Bitmap.createBitmap(bitmap, 0, 0, w, h, mtx, true);
		if (bitmap != null && !bitmap.isRecycled()) {
			bitmap.recycle();
		}
		return result;
	}

	public static boolean isPathBlacklisted(String path) {
		final String androidDataPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Android/data/";
		return path.startsWith(androidDataPath);
	}

	private static Paint createAntiAliasingPaint() {
		Paint paint = new Paint();
		paint.setAntiAlias(true);
		paint.setFilterBitmap(true);
		paint.setDither(true);
		return paint;
	}

	private static String getTakePhotoPath() {
		return Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM) + "/Camera/";
	}

	public static Uri getUriForFile(Context context, File file) {
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N || Config.ONLY_INTERNAL_STORAGE) {
			try {
				return FileProvider.getUriForFile(context, getAuthority(context), file);
			} catch (IllegalArgumentException e) {
				if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
					throw new SecurityException(e);
				} else {
					return Uri.fromFile(file);
				}
			}
		} else {
			return Uri.fromFile(file);
		}
	}

	public static String getAuthority(Context context) {
		return context.getPackageName() + FILE_PROVIDER;
	}

	public static Uri getIndexableTakePhotoUri(Uri original) {
		if (Config.ONLY_INTERNAL_STORAGE || "file".equals(original.getScheme())) {
			return original;
		} else {
			List<String> segments = original.getPathSegments();
			return Uri.parse("file://" + getTakePhotoPath() + segments.get(segments.size() - 1));
		}
	}

	private static boolean hasAlpha(final Bitmap bitmap) {
		for (int x = 0; x < bitmap.getWidth(); ++x) {
			for (int y = 0; y < bitmap.getWidth(); ++y) {
				if (Color.alpha(bitmap.getPixel(x, y)) < 255) {
					return true;
				}
			}
		}
		return false;
	}

	private static int calcSampleSize(File image, int size) {
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		BitmapFactory.decodeFile(image.getAbsolutePath(), options);
		return calcSampleSize(options, size);
	}

	public static int calcSampleSize(BitmapFactory.Options options, int size) {
		int height = options.outHeight;
		int width = options.outWidth;
		int inSampleSize = 1;

		if (height > size || width > size) {
			int halfHeight = height / 2;
			int halfWidth = width / 2;

			while ((halfHeight / inSampleSize) > size
					&& (halfWidth / inSampleSize) > size) {
				inSampleSize *= 2;
			}
		}
		return inSampleSize;
	}

	private static Dimensions getVideoDimensions(Context context, Uri uri) throws NotAVideoFile {
		MediaMetadataRetriever mediaMetadataRetriever = new MediaMetadataRetriever();
		try {
			mediaMetadataRetriever.setDataSource(context, uri);
		} catch (RuntimeException e) {
			throw new NotAVideoFile(e);
		}
		return getVideoDimensions(mediaMetadataRetriever);
	}

	private static Dimensions getVideoDimensionsOfFrame(MediaMetadataRetriever mediaMetadataRetriever) {
		Bitmap bitmap = null;
		try {
			bitmap = mediaMetadataRetriever.getFrameAtTime();
			return new Dimensions(bitmap.getHeight(), bitmap.getWidth());
		} catch (Exception e) {
			return null;
		} finally {
			if (bitmap != null) {
				bitmap.recycle();
				;
			}
		}
	}

	private static Dimensions getVideoDimensions(MediaMetadataRetriever metadataRetriever) throws NotAVideoFile {
		String hasVideo = metadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_HAS_VIDEO);
		if (hasVideo == null) {
			throw new NotAVideoFile();
		}
		Dimensions dimensions = getVideoDimensionsOfFrame(metadataRetriever);
		if (dimensions != null) {
			return dimensions;
		}
		int rotation = extractRotationFromMediaRetriever(metadataRetriever);
		boolean rotated = rotation == 90 || rotation == 270;
		int height;
		try {
			String h = metadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT);
			height = Integer.parseInt(h);
		} catch (Exception e) {
			height = -1;
		}
		int width;
		try {
			String w = metadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH);
			width = Integer.parseInt(w);
		} catch (Exception e) {
			width = -1;
		}
		metadataRetriever.release();
		Log.d(Config.LOGTAG, "extracted video dims " + width + "x" + height);
		return rotated ? new Dimensions(width, height) : new Dimensions(height, width);
	}

	private static int extractRotationFromMediaRetriever(MediaMetadataRetriever metadataRetriever) {
		String r = metadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION);
		try {
			return Integer.parseInt(r);
		} catch (Exception e) {
			return 0;
		}
	}

	public static void close(Closeable stream) {
		if (stream != null) {
			try {
				stream.close();
			} catch (IOException e) {
			}
		}
	}

	public static void close(Socket socket) {
		if (socket != null) {
			try {
				socket.close();
			} catch (IOException e) {
			}
		}
	}

	public static boolean weOwnFile(Context context, Uri uri) {
		if (uri == null || !ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
			return false;
		} else if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
			return fileIsInFilesDir(context, uri);
		} else {
			return weOwnFileLollipop(uri);
		}
	}

	/**
	 * This is more than hacky but probably way better than doing nothing
	 * Further 'optimizations' might contain to get the parents of CacheDir and NoBackupDir
	 * and check against those as well
	 */
	private static boolean fileIsInFilesDir(Context context, Uri uri) {
		try {
			final String haystack = context.getFilesDir().getParentFile().getCanonicalPath();
			final String needle = new File(uri.getPath()).getCanonicalPath();
			return needle.startsWith(haystack);
		} catch (IOException e) {
			return false;
		}
	}

	@TargetApi(Build.VERSION_CODES.LOLLIPOP)
	private static boolean weOwnFileLollipop(Uri uri) {
		try {
			File file = new File(uri.getPath());
			FileDescriptor fd = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY).getFileDescriptor();
			StructStat st = Os.fstat(fd);
			return st.st_uid == android.os.Process.myUid();
		} catch (FileNotFoundException e) {
			return false;
		} catch (Exception e) {
			return true;
		}
	}

	private void createNoMedia(File diretory) {
		final File noMedia = new File(diretory, ".nomedia");
		if (!noMedia.exists()) {
			try {
				if (!noMedia.createNewFile()) {
					Log.d(Config.LOGTAG, "created nomedia file " + noMedia.getAbsolutePath());
				}
			} catch (Exception e) {
				Log.d(Config.LOGTAG, "could not create nomedia file");
			}
		}
	}

	public void updateMediaScanner(File file) {
		if (!isInDirectoryThatShouldNotBeScanned(mXmppConnectionService, file)) {
			Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
			intent.setData(Uri.fromFile(file));
			mXmppConnectionService.sendBroadcast(intent);
		} else if (file.getAbsolutePath().startsWith(getAppMediaDirectory(mXmppConnectionService))) {
			createNoMedia(file.getParentFile());
		}
	}

	public boolean deleteFile(Message message) {
		File file = getFile(message);
		if (file.delete()) {
			updateMediaScanner(file);
			return true;
		} else {
			return false;
		}
	}

	public DownloadableFile getFile(Message message) {
		return getFile(message, true);
	}

	public DownloadableFile getFileForPath(String path, String mime) {
		final DownloadableFile file;
		if (path.startsWith("/")) {
			file = new DownloadableFile(path);
		} else {
			if (mime != null && mime.startsWith("image/")) {
				file = new DownloadableFile(getConversationsDirectory("Images") + path);
			} else if (mime != null && mime.startsWith("video/")) {
				file = new DownloadableFile(getConversationsDirectory("Videos") + path);
			} else {
				file = new DownloadableFile(getConversationsDirectory("Files") + path);
			}
		}
		return file;
	}

	public DownloadableFile getFile(Message message, boolean decrypted) {
		final boolean encrypted = !decrypted
				&& (message.getEncryption() == Message.ENCRYPTION_PGP
				|| message.getEncryption() == Message.ENCRYPTION_DECRYPTED);
		String path = message.getRelativeFilePath();
		if (path == null) {
			path = message.getUuid();
		}
		final DownloadableFile file = getFileForPath(path, message.getMimeType());
		if (encrypted) {
			return new DownloadableFile(getConversationsDirectory("Files") + file.getName() + ".pgp");
		} else {
			return file;
		}
	}

	public String getConversationsDirectory(final String type) {
		return getConversationsDirectory(mXmppConnectionService, type);
	}

	private Bitmap resize(final Bitmap originalBitmap, int size) throws IOException {
		int w = originalBitmap.getWidth();
		int h = originalBitmap.getHeight();
		if (w <= 0 || h <= 0) {
			throw new IOException("Decoded bitmap reported bounds smaller 0");
		} else if (Math.max(w, h) > size) {
			int scalledW;
			int scalledH;
			if (w <= h) {
				scalledW = Math.max((int) (w / ((double) h / size)), 1);
				scalledH = size;
			} else {
				scalledW = size;
				scalledH = Math.max((int) (h / ((double) w / size)), 1);
			}
			final Bitmap result = Bitmap.createScaledBitmap(originalBitmap, scalledW, scalledH, true);
			if (!originalBitmap.isRecycled()) {
				originalBitmap.recycle();
			}
			return result;
		} else {
			return originalBitmap;
		}
	}

	public boolean useImageAsIs(Uri uri) {
		String path = getOriginalPath(uri);
		if (path == null || isPathBlacklisted(path)) {
			return false;
		}
		File file = new File(path);
		long size = file.length();
		if (size == 0 || size >= mXmppConnectionService.getResources().getInteger(R.integer.auto_accept_filesize)) {
			return false;
		}
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		try {
			BitmapFactory.decodeStream(mXmppConnectionService.getContentResolver().openInputStream(uri), null, options);
			if (options.outMimeType == null || options.outHeight <= 0 || options.outWidth <= 0) {
				return false;
			}
			return (options.outWidth <= Config.IMAGE_SIZE && options.outHeight <= Config.IMAGE_SIZE && options.outMimeType.contains(Config.IMAGE_FORMAT.name().toLowerCase()));
		} catch (FileNotFoundException e) {
			return false;
		}
	}

	public String getOriginalPath(Uri uri) {
		return FileUtils.getPath(mXmppConnectionService, uri);
	}

	private void copyFileToPrivateStorage(File file, Uri uri) throws FileCopyException {
		Log.d(Config.LOGTAG, "copy file (" + uri.toString() + ") to private storage " + file.getAbsolutePath());
		file.getParentFile().mkdirs();
		OutputStream os = null;
		InputStream is = null;
		try {
			file.createNewFile();
			os = new FileOutputStream(file);
			is = mXmppConnectionService.getContentResolver().openInputStream(uri);
			byte[] buffer = new byte[1024];
			int length;
			while ((length = is.read(buffer)) > 0) {
				try {
					os.write(buffer, 0, length);
				} catch (IOException e) {
					throw new FileWriterException();
				}
			}
			try {
				os.flush();
			} catch (IOException e) {
				throw new FileWriterException();
			}
		} catch (FileNotFoundException e) {
			throw new FileCopyException(R.string.error_file_not_found);
		} catch (FileWriterException e) {
			throw new FileCopyException(R.string.error_unable_to_create_temporary_file);
		} catch (IOException e) {
			e.printStackTrace();
			throw new FileCopyException(R.string.error_io_exception);
		} finally {
			close(os);
			close(is);
		}
	}

	public void copyFileToPrivateStorage(Message message, Uri uri, String type) throws FileCopyException {
		String mime = type != null ? type : MimeUtils.guessMimeTypeFromUri(mXmppConnectionService, uri);
		Log.d(Config.LOGTAG, "copy " + uri.toString() + " to private storage (mime=" + mime + ")");
		String extension = MimeUtils.guessExtensionFromMimeType(mime);
		if (extension == null) {
			Log.d(Config.LOGTAG, "extension from mime type was null");
			extension = getExtensionFromUri(uri);
		}
		if ("ogg".equals(extension) && type != null && type.startsWith("audio/")) {
			extension = "oga";
		}
		message.setRelativeFilePath(message.getUuid() + "." + extension);
		copyFileToPrivateStorage(mXmppConnectionService.getFileBackend().getFile(message), uri);
	}

	private String getExtensionFromUri(Uri uri) {
		String[] projection = {MediaStore.MediaColumns.DATA};
		String filename = null;
		Cursor cursor = mXmppConnectionService.getContentResolver().query(uri, projection, null, null, null);
		if (cursor != null) {
			try {
				if (cursor.moveToFirst()) {
					filename = cursor.getString(0);
				}
			} catch (Exception e) {
				filename = null;
			} finally {
				cursor.close();
			}
		}
		if (filename == null) {
			final List<String> segments = uri.getPathSegments();
			if (segments.size() > 0) {
				filename = segments.get(segments.size() - 1);
			}
		}
		int pos = filename == null ? -1 : filename.lastIndexOf('.');
		return pos > 0 ? filename.substring(pos + 1) : null;
	}

	private void copyImageToPrivateStorage(File file, Uri image, int sampleSize) throws FileCopyException {
		file.getParentFile().mkdirs();
		InputStream is = null;
		OutputStream os = null;
		try {
			if (!file.exists() && !file.createNewFile()) {
				throw new FileCopyException(R.string.error_unable_to_create_temporary_file);
			}
			is = mXmppConnectionService.getContentResolver().openInputStream(image);
			if (is == null) {
				throw new FileCopyException(R.string.error_not_an_image_file);
			}
			Bitmap originalBitmap;
			BitmapFactory.Options options = new BitmapFactory.Options();
			int inSampleSize = (int) Math.pow(2, sampleSize);
			Log.d(Config.LOGTAG, "reading bitmap with sample size " + inSampleSize);
			options.inSampleSize = inSampleSize;
			originalBitmap = BitmapFactory.decodeStream(is, null, options);
			is.close();
			if (originalBitmap == null) {
				throw new FileCopyException(R.string.error_not_an_image_file);
			}
			Bitmap scaledBitmap = resize(originalBitmap, Config.IMAGE_SIZE);
			int rotation = getRotation(image);
			scaledBitmap = rotate(scaledBitmap, rotation);
			boolean targetSizeReached = false;
			int quality = Config.IMAGE_QUALITY;
			final int imageMaxSize = mXmppConnectionService.getResources().getInteger(R.integer.auto_accept_filesize);
			while (!targetSizeReached) {
				os = new FileOutputStream(file);
				boolean success = scaledBitmap.compress(Config.IMAGE_FORMAT, quality, os);
				if (!success) {
					throw new FileCopyException(R.string.error_compressing_image);
				}
				os.flush();
				targetSizeReached = file.length() <= imageMaxSize || quality <= 50;
				quality -= 5;
			}
			scaledBitmap.recycle();
		} catch (FileNotFoundException e) {
			throw new FileCopyException(R.string.error_file_not_found);
		} catch (IOException e) {
			e.printStackTrace();
			throw new FileCopyException(R.string.error_io_exception);
		} catch (SecurityException e) {
			throw new FileCopyException(R.string.error_security_exception_during_image_copy);
		} catch (OutOfMemoryError e) {
			++sampleSize;
			if (sampleSize <= 3) {
				copyImageToPrivateStorage(file, image, sampleSize);
			} else {
				throw new FileCopyException(R.string.error_out_of_memory);
			}
		} finally {
			close(os);
			close(is);
		}
	}

	public void copyImageToPrivateStorage(File file, Uri image) throws FileCopyException {
		Log.d(Config.LOGTAG, "copy image (" + image.toString() + ") to private storage " + file.getAbsolutePath());
		copyImageToPrivateStorage(file, image, 0);
	}

	public void copyImageToPrivateStorage(Message message, Uri image) throws FileCopyException {
		switch (Config.IMAGE_FORMAT) {
			case JPEG:
				message.setRelativeFilePath(message.getUuid() + ".jpg");
				break;
			case PNG:
				message.setRelativeFilePath(message.getUuid() + ".png");
				break;
			case WEBP:
				message.setRelativeFilePath(message.getUuid() + ".webp");
				break;
		}
		copyImageToPrivateStorage(getFile(message), image);
		updateFileParams(message);
	}

	private int getRotation(File file) {
		return getRotation(Uri.parse("file://" + file.getAbsolutePath()));
	}

	private int getRotation(Uri image) {
		InputStream is = null;
		try {
			is = mXmppConnectionService.getContentResolver().openInputStream(image);
			return ExifHelper.getOrientation(is);
		} catch (FileNotFoundException e) {
			return 0;
		} finally {
			close(is);
		}
	}

	public Bitmap getThumbnail(Message message, int size, boolean cacheOnly) throws IOException {
		final String uuid = message.getUuid();
		final LruCache<String, Bitmap> cache = mXmppConnectionService.getBitmapCache();
		Bitmap thumbnail = cache.get(uuid);
		if ((thumbnail == null) && (!cacheOnly)) {
			synchronized (THUMBNAIL_LOCK) {
				thumbnail = cache.get(uuid);
				if (thumbnail != null) {
					return thumbnail;
				}
				DownloadableFile file = getFile(message);
				final String mime = file.getMimeType();
				if (mime.startsWith("video/")) {
					thumbnail = getVideoPreview(file, size);
				} else {
					Bitmap fullsize = getFullsizeImagePreview(file, size);
					if (fullsize == null) {
						throw new FileNotFoundException();
					}
					thumbnail = resize(fullsize, size);
					thumbnail = rotate(thumbnail, getRotation(file));
					if (mime.equals("image/gif")) {
						Bitmap withGifOverlay = thumbnail.copy(Bitmap.Config.ARGB_8888, true);
						drawOverlay(withGifOverlay, R.drawable.play_gif, 1.0f);
						thumbnail.recycle();
						thumbnail = withGifOverlay;
					}
				}
				this.mXmppConnectionService.getBitmapCache().put(uuid, thumbnail);
			}
		}
		return thumbnail;
	}

	private Bitmap getFullsizeImagePreview(File file, int size) {
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inSampleSize = calcSampleSize(file, size);
		try {
			return BitmapFactory.decodeFile(file.getAbsolutePath(), options);
		} catch (OutOfMemoryError e) {
			options.inSampleSize *= 2;
			return BitmapFactory.decodeFile(file.getAbsolutePath(), options);
		}
	}

	private void drawOverlay(Bitmap bitmap, int resource, float factor) {
		Bitmap overlay = BitmapFactory.decodeResource(mXmppConnectionService.getResources(), resource);
		Canvas canvas = new Canvas(bitmap);
		float targetSize = Math.min(canvas.getWidth(), canvas.getHeight()) * factor;
		Log.d(Config.LOGTAG, "target size overlay: " + targetSize + " overlay bitmap size was " + overlay.getHeight());
		float left = (canvas.getWidth() - targetSize) / 2.0f;
		float top = (canvas.getHeight() - targetSize) / 2.0f;
		RectF dst = new RectF(left, top, left + targetSize - 1, top + targetSize - 1);
		canvas.drawBitmap(overlay, null, dst, createAntiAliasingPaint());
	}

	private Bitmap getVideoPreview(File file, int size) {
		MediaMetadataRetriever metadataRetriever = new MediaMetadataRetriever();
		Bitmap frame;
		try {
			metadataRetriever.setDataSource(file.getAbsolutePath());
			frame = metadataRetriever.getFrameAtTime(0);
			metadataRetriever.release();
			frame = resize(frame, size);
		} catch (IOException | RuntimeException e) {
			frame = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
			frame.eraseColor(0xff000000);
		}
		drawOverlay(frame, R.drawable.play_video, 0.75f);
		return frame;
	}

	public Uri getTakePhotoUri() {
		File file;
		if (Config.ONLY_INTERNAL_STORAGE) {
			file = new File(mXmppConnectionService.getCacheDir().getAbsolutePath(), "Camera/IMG_" + this.IMAGE_DATE_FORMAT.format(new Date()) + ".jpg");
		} else {
			file = new File(getTakePhotoPath() + "IMG_" + this.IMAGE_DATE_FORMAT.format(new Date()) + ".jpg");
		}
		file.getParentFile().mkdirs();
		return getUriForFile(mXmppConnectionService, file);
	}

	public Avatar getPepAvatar(Uri image, int size, Bitmap.CompressFormat format) {
		Bitmap bm = cropCenterSquare(image, size);
		if (bm == null) {
			return null;
		}
		if (hasAlpha(bm)) {
			Log.d(Config.LOGTAG, "alpha in avatar detected; uploading as PNG");
			bm.recycle();
			bm = cropCenterSquare(image, 96);
			return getPepAvatar(bm, Bitmap.CompressFormat.PNG, 100);
		}
		return getPepAvatar(bm, format, 100);
	}

	private Avatar getPepAvatar(Bitmap bitmap, Bitmap.CompressFormat format, int quality) {
		try {
			ByteArrayOutputStream mByteArrayOutputStream = new ByteArrayOutputStream();
			Base64OutputStream mBase64OutputStream = new Base64OutputStream(mByteArrayOutputStream, Base64.DEFAULT);
			MessageDigest digest = MessageDigest.getInstance("SHA-1");
			DigestOutputStream mDigestOutputStream = new DigestOutputStream(mBase64OutputStream, digest);
			if (!bitmap.compress(format, quality, mDigestOutputStream)) {
				return null;
			}
			mDigestOutputStream.flush();
			mDigestOutputStream.close();
			long chars = mByteArrayOutputStream.size();
			if (format != Bitmap.CompressFormat.PNG && quality >= 50 && chars >= Config.AVATAR_CHAR_LIMIT) {
				int q = quality - 2;
				Log.d(Config.LOGTAG, "avatar char length was " + chars + " reducing quality to " + q);
				return getPepAvatar(bitmap, format, q);
			}
			Log.d(Config.LOGTAG, "settled on char length " + chars + " with quality=" + quality);
			final Avatar avatar = new Avatar();
			avatar.sha1sum = CryptoHelper.bytesToHex(digest.digest());
			avatar.image = new String(mByteArrayOutputStream.toByteArray());
			if (format.equals(Bitmap.CompressFormat.WEBP)) {
				avatar.type = "image/webp";
			} else if (format.equals(Bitmap.CompressFormat.JPEG)) {
				avatar.type = "image/jpeg";
			} else if (format.equals(Bitmap.CompressFormat.PNG)) {
				avatar.type = "image/png";
			}
			avatar.width = bitmap.getWidth();
			avatar.height = bitmap.getHeight();
			return avatar;
		} catch (Exception e) {
			return null;
		}
	}

	public Avatar getStoredPepAvatar(String hash) {
		if (hash == null) {
			return null;
		}
		Avatar avatar = new Avatar();
		File file = new File(getAvatarPath(hash));
		FileInputStream is = null;
		try {
			avatar.size = file.length();
			BitmapFactory.Options options = new BitmapFactory.Options();
			options.inJustDecodeBounds = true;
			BitmapFactory.decodeFile(file.getAbsolutePath(), options);
			is = new FileInputStream(file);
			ByteArrayOutputStream mByteArrayOutputStream = new ByteArrayOutputStream();
			Base64OutputStream mBase64OutputStream = new Base64OutputStream(mByteArrayOutputStream, Base64.DEFAULT);
			MessageDigest digest = MessageDigest.getInstance("SHA-1");
			DigestOutputStream os = new DigestOutputStream(mBase64OutputStream, digest);
			byte[] buffer = new byte[4096];
			int length;
			while ((length = is.read(buffer)) > 0) {
				os.write(buffer, 0, length);
			}
			os.flush();
			os.close();
			avatar.sha1sum = CryptoHelper.bytesToHex(digest.digest());
			avatar.image = new String(mByteArrayOutputStream.toByteArray());
			avatar.height = options.outHeight;
			avatar.width = options.outWidth;
			avatar.type = options.outMimeType;
			return avatar;
		} catch (NoSuchAlgorithmException | IOException e) {
			return null;
		} finally {
			close(is);
		}
	}

	public boolean isAvatarCached(Avatar avatar) {
		File file = new File(getAvatarPath(avatar.getFilename()));
		return file.exists();
	}

	public boolean save(final Avatar avatar) {
		File file;
		if (isAvatarCached(avatar)) {
			file = new File(getAvatarPath(avatar.getFilename()));
			avatar.size = file.length();
		} else {
			file = new File(mXmppConnectionService.getCacheDir().getAbsolutePath() + "/" + UUID.randomUUID().toString());
			if (file.getParentFile().mkdirs()) {
				Log.d(Config.LOGTAG, "created cache directory");
			}
			OutputStream os = null;
			try {
				if (!file.createNewFile()) {
					Log.d(Config.LOGTAG, "unable to create temporary file " + file.getAbsolutePath());
				}
				os = new FileOutputStream(file);
				MessageDigest digest = MessageDigest.getInstance("SHA-1");
				digest.reset();
				DigestOutputStream mDigestOutputStream = new DigestOutputStream(os, digest);
				final byte[] bytes = avatar.getImageAsBytes();
				mDigestOutputStream.write(bytes);
				mDigestOutputStream.flush();
				mDigestOutputStream.close();
				String sha1sum = CryptoHelper.bytesToHex(digest.digest());
				if (sha1sum.equals(avatar.sha1sum)) {
					File outputFile = new File(getAvatarPath(avatar.getFilename()));
					if (outputFile.getParentFile().mkdirs()) {
						Log.d(Config.LOGTAG, "created avatar directory");
					}
					String filename = getAvatarPath(avatar.getFilename());
					if (!file.renameTo(new File(filename))) {
						Log.d(Config.LOGTAG, "unable to rename " + file.getAbsolutePath() + " to " + outputFile);
						return false;
					}
				} else {
					Log.d(Config.LOGTAG, "sha1sum mismatch for " + avatar.owner);
					if (!file.delete()) {
						Log.d(Config.LOGTAG, "unable to delete temporary file");
					}
					return false;
				}
				avatar.size = bytes.length;
			} catch (IllegalArgumentException | IOException | NoSuchAlgorithmException e) {
				return false;
			} finally {
				close(os);
			}
		}
		return true;
	}

	private String getAvatarPath(String avatar) {
		return mXmppConnectionService.getFilesDir().getAbsolutePath() + "/avatars/" + avatar;
	}

	public Uri getAvatarUri(String avatar) {
		return Uri.parse("file:" + getAvatarPath(avatar));
	}

	public Bitmap cropCenterSquare(Uri image, int size) {
		if (image == null) {
			return null;
		}
		InputStream is = null;
		try {
			BitmapFactory.Options options = new BitmapFactory.Options();
			options.inSampleSize = calcSampleSize(image, size);
			is = mXmppConnectionService.getContentResolver().openInputStream(image);
			if (is == null) {
				return null;
			}
			Bitmap input = BitmapFactory.decodeStream(is, null, options);
			if (input == null) {
				return null;
			} else {
				input = rotate(input, getRotation(image));
				return cropCenterSquare(input, size);
			}
		} catch (FileNotFoundException | SecurityException e) {
			return null;
		} finally {
			close(is);
		}
	}

	public Bitmap cropCenter(Uri image, int newHeight, int newWidth) {
		if (image == null) {
			return null;
		}
		InputStream is = null;
		try {
			BitmapFactory.Options options = new BitmapFactory.Options();
			options.inSampleSize = calcSampleSize(image, Math.max(newHeight, newWidth));
			is = mXmppConnectionService.getContentResolver().openInputStream(image);
			if (is == null) {
				return null;
			}
			Bitmap source = BitmapFactory.decodeStream(is, null, options);
			if (source == null) {
				return null;
			}
			int sourceWidth = source.getWidth();
			int sourceHeight = source.getHeight();
			float xScale = (float) newWidth / sourceWidth;
			float yScale = (float) newHeight / sourceHeight;
			float scale = Math.max(xScale, yScale);
			float scaledWidth = scale * sourceWidth;
			float scaledHeight = scale * sourceHeight;
			float left = (newWidth - scaledWidth) / 2;
			float top = (newHeight - scaledHeight) / 2;

			RectF targetRect = new RectF(left, top, left + scaledWidth, top + scaledHeight);
			Bitmap dest = Bitmap.createBitmap(newWidth, newHeight, Bitmap.Config.ARGB_8888);
			Canvas canvas = new Canvas(dest);
			canvas.drawBitmap(source, null, targetRect, createAntiAliasingPaint());
			if (source.isRecycled()) {
				source.recycle();
			}
			return dest;
		} catch (SecurityException e) {
			return null; //android 6.0 with revoked permissions for example
		} catch (FileNotFoundException e) {
			return null;
		} finally {
			close(is);
		}
	}

	public Bitmap cropCenterSquare(Bitmap input, int size) {
		int w = input.getWidth();
		int h = input.getHeight();

		float scale = Math.max((float) size / h, (float) size / w);

		float outWidth = scale * w;
		float outHeight = scale * h;
		float left = (size - outWidth) / 2;
		float top = (size - outHeight) / 2;
		RectF target = new RectF(left, top, left + outWidth, top + outHeight);

		Bitmap output = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
		Canvas canvas = new Canvas(output);
		canvas.drawBitmap(input, null, target, createAntiAliasingPaint());
		if (!input.isRecycled()) {
			input.recycle();
		}
		return output;
	}

	private int calcSampleSize(Uri image, int size) throws FileNotFoundException, SecurityException {
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		BitmapFactory.decodeStream(mXmppConnectionService.getContentResolver().openInputStream(image), null, options);
		return calcSampleSize(options, size);
	}

	public void updateFileParams(Message message) {
		updateFileParams(message, null);
	}

	public void updateFileParams(Message message, URL url) {
		DownloadableFile file = getFile(message);
		final String mime = file.getMimeType();
		boolean image = message.getType() == Message.TYPE_IMAGE || (mime != null && mime.startsWith("image/"));
		boolean video = mime != null && mime.startsWith("video/");
		boolean audio = mime != null && mime.startsWith("audio/");
		final StringBuilder body = new StringBuilder();
		if (url != null) {
			body.append(url.toString());
		}
		body.append('|').append(file.getSize());
		if (image || video) {
			try {
				Dimensions dimensions = image ? getImageDimensions(file) : getVideoDimensions(file);
				if (dimensions.valid()) {
					body.append('|').append(dimensions.width).append('|').append(dimensions.height);
				}
			} catch (NotAVideoFile notAVideoFile) {
				Log.d(Config.LOGTAG, "file with mime type " + file.getMimeType() + " was not a video file");
				//fall threw
			}
		} else if (audio) {
			body.append("|0|0|").append(getMediaRuntime(file));
		}
		message.setBody(body.toString());
	}

	public int getMediaRuntime(Uri uri) {
		try {
			MediaMetadataRetriever mediaMetadataRetriever = new MediaMetadataRetriever();
			mediaMetadataRetriever.setDataSource(mXmppConnectionService, uri);
			return Integer.parseInt(mediaMetadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION));
		} catch (RuntimeException e) {
			return 0;
		}
	}

	private int getMediaRuntime(File file) {
		try {
			MediaMetadataRetriever mediaMetadataRetriever = new MediaMetadataRetriever();
			mediaMetadataRetriever.setDataSource(file.toString());
			return Integer.parseInt(mediaMetadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION));
		} catch (RuntimeException e) {
			return 0;
		}
	}

	private Dimensions getImageDimensions(File file) {
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		BitmapFactory.decodeFile(file.getAbsolutePath(), options);
		int rotation = getRotation(file);
		boolean rotated = rotation == 90 || rotation == 270;
		int imageHeight = rotated ? options.outWidth : options.outHeight;
		int imageWidth = rotated ? options.outHeight : options.outWidth;
		return new Dimensions(imageHeight, imageWidth);
	}

	private Dimensions getVideoDimensions(File file) throws NotAVideoFile {
		MediaMetadataRetriever metadataRetriever = new MediaMetadataRetriever();
		try {
			metadataRetriever.setDataSource(file.getAbsolutePath());
		} catch (RuntimeException e) {
			throw new NotAVideoFile(e);
		}
		return getVideoDimensions(metadataRetriever);
	}

	public Bitmap getAvatar(String avatar, int size) {
		if (avatar == null) {
			return null;
		}
		Bitmap bm = cropCenter(getAvatarUri(avatar), size, size);
		if (bm == null) {
			return null;
		}
		return bm;
	}

	public boolean isFileAvailable(Message message) {
		return getFile(message).exists();
	}

	private static class Dimensions {
		public final int width;
		public final int height;

		Dimensions(int height, int width) {
			this.width = width;
			this.height = height;
		}

		public int getMin() {
			return Math.min(width, height);
		}

		public boolean valid() {
			return width > 0 && height > 0;
		}
	}

	private static class NotAVideoFile extends Exception {
		public NotAVideoFile(Throwable t) {
			super(t);
		}

		public NotAVideoFile() {
			super();
		}
	}

	public class FileCopyException extends Exception {
		private static final long serialVersionUID = -1010013599132881427L;
		private int resId;

		public FileCopyException(int resId) {
			this.resId = resId;
		}

		public int getResId() {
			return resId;
		}
	}
}