package eu.siacs.conversations.persistance;

import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Environment;
import android.util.Log;
import android.webkit.MimeTypeMap;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import de.thedevstack.android.logcat.Logging;
import de.thedevstack.conversationsplus.ConversationsPlusApplication;
import de.thedevstack.conversationsplus.ConversationsPlusPreferences;
import de.thedevstack.conversationsplus.exceptions.FileCopyException;
import de.thedevstack.conversationsplus.persistance.observers.FileDeletionObserver;
import de.thedevstack.conversationsplus.utils.StreamUtil;
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;

public class FileBackend {
	private static final SimpleDateFormat imageDateFormat = new SimpleDateFormat("yyyyMMdd_HHmmssSSS", Locale.US);
    private static FileBackend INSTANCE;

    private FileDeletionObserver privateFilesDirectoryObserver;
    private FileDeletionObserver privateFilesImageDirectoryObserver;
    private FileDeletionObserver conversationsFilesDirectoryObserver;
    private FileDeletionObserver conversationsImagesDirectoryObserver;

    public static void init() {
        if (null == INSTANCE) {
            INSTANCE = new FileBackend();
        }
        INSTANCE.initFileObservers();
        INSTANCE.createNoMedia();
    }

    private void initFileObservers() {
        this.privateFilesDirectoryObserver = new FileDeletionObserver(FileBackend.getPrivateFileDirectoryPath());
        this.privateFilesImageDirectoryObserver = new FileDeletionObserver(FileBackend.getConversationsFileDirectory());
        this.conversationsFilesDirectoryObserver = new FileDeletionObserver(FileBackend.getConversationsImageDirectory());
        this.conversationsImagesDirectoryObserver = new FileDeletionObserver(FileBackend.getPrivateImageDirectoryPath());

        this.privateFilesDirectoryObserver.startWatching();
        this.privateFilesImageDirectoryObserver.startWatching();
        this.conversationsFilesDirectoryObserver.startWatching();
        this.conversationsImagesDirectoryObserver.startWatching();
    }

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

    public static void onFileTransferFolderChanged() {
        INSTANCE.conversationsFilesDirectoryObserver.stopWatching();
        INSTANCE.conversationsFilesDirectoryObserver = new FileDeletionObserver(FileBackend.getConversationsFileDirectory());
        INSTANCE.conversationsFilesDirectoryObserver.startWatching();
        INSTANCE.createNoMedia();
    }

    public static void onImageTransferFolderChanged() {
        INSTANCE.conversationsImagesDirectoryObserver.stopWatching();
        INSTANCE.conversationsImagesDirectoryObserver = new FileDeletionObserver(FileBackend.getConversationsImageDirectory());
        INSTANCE.conversationsImagesDirectoryObserver.startWatching();
    }

	public static void updateMediaScanner(File file, XmppConnectionService xmppConnectionService) {
		if (file.getAbsolutePath().startsWith(getConversationsImageDirectory())) {
			Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
			intent.setData(Uri.fromFile(file));
			xmppConnectionService.sendBroadcast(intent);
		}
	}

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

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

	public static DownloadableFile getFile(Message message, boolean decrypted) {
		final boolean encrypted = !decrypted
				&& (message.getEncryption() == Message.ENCRYPTION_PGP
				|| message.getEncryption() == Message.ENCRYPTION_DECRYPTED);
		final DownloadableFile file;
		String path = message.getRelativeFilePath();
		if (path == null) {
			path = message.getUuid();
		}
		if (path.startsWith("/")) {
			file = new DownloadableFile(path);
		} else {
			String mime = message.getMimeType();
			if (mime != null && mime.startsWith("image")) {
				file = new DownloadableFile(getConversationsImageDirectory() + path);
			} else {
				file = new DownloadableFile(getConversationsFileDirectory() + path);
			}
		}
		if (encrypted) {
			return new DownloadableFile(getConversationsFileDirectory() + file.getName() + ".pgp");
		} else {
			return file;
		}
	}

	public static String getConversationsFileDirectory() {
		return  Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + ConversationsPlusPreferences.fileTransferFolder() + File.separator;
	}

	public static String getConversationsImageDirectory() {
		return Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsolutePath() + File.separator + ConversationsPlusPreferences.imgTransferFolder() + File.separator;
	}

    public static String getPrivateFileDirectoryPath() {
        return ConversationsPlusApplication.getPrivateFilesDir().getAbsolutePath();
    }

    private static String getPrivateImageDirectoryPath() {
        return FileBackend.getPrivateFileDirectoryPath() + File.separator + "Images" + File.separator;
    }

	public static void copyFileToPrivateStorage(File file, Uri uri) throws FileCopyException {
		file.getParentFile().mkdirs();
		OutputStream os = null;
		InputStream is = null;
		try {
			file.createNewFile();
			os = new FileOutputStream(file);
			is = StreamUtil.openInputStreamFromContentResolver(uri);
			byte[] buffer = new byte[1024];
			int length;
			while ((length = is.read(buffer)) > 0) {
				os.write(buffer, 0, length);
			}
			os.flush();
		} 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);
		} finally {
			StreamUtil.close(os);
			StreamUtil.close(is);
		}
		Logging.d(Config.LOGTAG, "output file name " + file);
	}

	public static void copyFileToPrivateStorage(Message message, Uri uri) throws FileCopyException {
		Log.d(Config.LOGTAG, "copy " + uri.toString() + " to private storage");
		String mime = ConversationsPlusApplication.getInstance().getContentResolver().getType(uri);
		String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mime);
		message.setRelativeFilePath(message.getUuid() + "." + extension);
		copyFileToPrivateStorage(getFile(message), uri);
	}

    public static DownloadableFile compressImageAndCopyToPrivateStorage(Message message, Bitmap scaledBitmap) throws FileCopyException {
        message.setRelativeFilePath(FileBackend.getPrivateImageDirectoryPath() + message.getUuid() + ".jpg");
        DownloadableFile file = getFile(message);
        file.getParentFile().mkdirs();
        OutputStream os = null;
        try {
            file.createNewFile();
            os = new FileOutputStream(file);

            boolean success = scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 75, os);
            if (!success) {
                throw new FileCopyException(R.string.error_compressing_image);
            }
            os.flush();
        } catch (IOException e) {
            throw new FileCopyException(R.string.error_io_exception, e);
        } catch (SecurityException e) {
            throw new FileCopyException(R.string.error_security_exception_during_image_copy);
        } catch (NullPointerException e) {
            throw new FileCopyException(R.string.error_io_exception);
        } finally {
            StreamUtil.close(os);
        }
        return file;
    }

	public static Uri getTakePhotoUri() {
		StringBuilder pathBuilder = new StringBuilder();
		pathBuilder.append(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM));
		pathBuilder.append('/');
		pathBuilder.append("Camera");
		pathBuilder.append('/');
		pathBuilder.append("IMG_" + imageDateFormat.format(new Date()) + ".jpg");
		Uri uri = Uri.parse("file://" + pathBuilder.toString());
		File file = new File(uri.toString());
		file.getParentFile().mkdirs();
		return uri;
	}

	public static Uri getJingleFileUri(Message message) {
		File file = getFile(message);
		return Uri.parse("file://" + file.getAbsolutePath());
	}

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

    private FileBackend() {
        // Static helper class
    }
}