package eu.siacs.conversations.persistance;

import java.io.BufferedInputStream;
import java.io.File;
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.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.util.Log;
import android.util.LruCache;

import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.entities.Message;
import eu.siacs.conversations.utils.CryptoHelper;

public class FileBackend {

	private static int IMAGE_SIZE = 1920;

	private Context context;
	private LruCache<String, Bitmap> thumbnailCache;

	public FileBackend(Context context) {
		this.context = context;
		
		int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
		int cacheSize = maxMemory / 8;
		thumbnailCache = new LruCache<String, Bitmap>(cacheSize) {
			@Override
			protected int sizeOf(String key, Bitmap bitmap) {
				return bitmap.getByteCount() / 1024;
			}
		};

	}

	public File getImageFile(Message message) {
		Conversation conversation = message.getConversation();
		String prefix = context.getFilesDir().getAbsolutePath();
		String path = prefix + "/" + conversation.getAccount().getJid() + "/"
				+ conversation.getContactJid();
		String filename = message.getUuid() + ".webp";
		return new File(path + "/" + filename);
	}
	
	private Bitmap resize(Bitmap originalBitmap, int size) {
		int w = originalBitmap.getWidth();
		int h = originalBitmap.getHeight();
		if (Math.max(w, h) > size) {
			int scalledW;
			int scalledH;
			if (w <= h) {
				scalledW = (int) (w / ((double) h / size));
				scalledH = size;
			} else {
				scalledW = size;
				scalledH = (int) (h / ((double) w / size));
			}
			Bitmap scalledBitmap = Bitmap.createScaledBitmap(
					originalBitmap, scalledW, scalledH, true);
			return scalledBitmap;
		} else {
			return originalBitmap;
		}
	}

	public File copyImageToPrivateStorage(Message message, Uri image) {
		try {
			InputStream is = context.getContentResolver()
					.openInputStream(image);
			File file = getImageFile(message);
			file.getParentFile().mkdirs();
			file.createNewFile();
			OutputStream os = new FileOutputStream(file);
			Bitmap originalBitmap = BitmapFactory.decodeStream(is);
			is.close();
			Bitmap scalledBitmap = resize(originalBitmap, IMAGE_SIZE);
			boolean success = scalledBitmap.compress(Bitmap.CompressFormat.WEBP,75,os);
			if (!success) {
				Log.d("xmppService", "couldnt compress");
			}
			os.close();
			message.setBody(this.createSha1(file));
			return file;
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		return null;
	}

	public Bitmap getImageFromMessage(Message message) {
		return BitmapFactory
				.decodeFile(getImageFile(message).getAbsolutePath());
	}

	public Bitmap getThumbnailFromMessage(Message message, int size) {
		Bitmap thumbnail = thumbnailCache.get(message.getUuid());
		if (thumbnail==null) {
			Log.d("xmppService","creating new thumbnail" + message.getUuid());
			Bitmap fullsize = BitmapFactory.decodeFile(getImageFile(message)
					.getAbsolutePath());
			thumbnail = resize(fullsize, size);
			this.thumbnailCache.put(message.getUuid(), thumbnail);
		}
		return thumbnail;
	}
	
	private String createSha1(final File file) {
		InputStream fis = null;
		try {
			MessageDigest digest = MessageDigest.getInstance("SHA-1");
			fis = new FileInputStream(file);
		    int n = 0;
		    byte[] buffer = new byte[8192];
		    while (n != -1) {
		        n = fis.read(buffer);
		        if (n > 0) {
		            digest.update(buffer, 0, n);
		        }
		    }
		    fis.close();
		    return CryptoHelper.bytesToHex(digest.digest());
		} catch (NoSuchAlgorithmException e) {
			return null;
		} catch (FileNotFoundException e) {
			if (fis!=null) {
				try {
					fis.close();
					return null;
				} catch (IOException e1) {
					return null;
				}
			}
		} catch (IOException e) {
			if (fis!=null) {
				try {
					fis.close();
					return null;
				} catch (IOException e1) {
					return null;
				}
			}
		}
		return null;
	}
}