package ve.gob.cenditel.tibisaymovil;

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.nio.channels.FileChannel;
import java.util.Collection;

import android.content.Context;
import android.net.Uri;
import android.os.Environment;
import android.os.StatFs;
import android.text.format.DateFormat;
import android.util.Log;

/**
 * File system related utilities.
 *
 * @author José M. Prieto (jmprieto@emergya.com)
 */
public class FsUtils {

    private static final String TAG = "FsUtils";

    /**
     * Save raw data to a File.
     *
     * @param data the data to be saved
     * @param targetFilename name of the file to be created
     * @throws FileAlreadyExistsException if the file already exists
     * @throws FileNotFoundException if the file cannot be open for writing
     * @throws IOException if there is an I/O error
     */
    public static Uri saveToFile(byte[] data, String targetFilename)
    throws FileAlreadyExistsException, FileNotFoundException, IOException {

        File file = createNewFile(targetFilename);
        OutputStream stream = new FileOutputStream(file);
        stream.write(data);
        stream.close();
        return Uri.fromFile(file);
    }

    public static Uri saveToFile(InputStream data, String targetFilename)
    throws FileAlreadyExistsException, FileNotFoundException, IOException {

        File file = createNewFile(targetFilename);
        OutputStream stream = new FileOutputStream(file);
        byte[] buf = new byte[8192];
        int n;
        while ((n = data.read(buf)) > 0) {
            stream.write(buf, 0, n);
        }
        data.close();
        stream.close();
        return Uri.fromFile(file);
    }

    public static void copyTo(File file, String directory)
    throws IOException {

        String target = directory + File.separator + file.getName();
        FileChannel source = null;
        FileChannel destination = null;

        try {
            destination = new FileOutputStream(createNewFile(target)).getChannel();
            source = new FileInputStream(file).getChannel();
            destination.transferFrom(source, 0, source.size());
        } finally {
            if (source != null) {
                source.close();
            }
            if (destination != null) {
                destination.close();
            }
        }
    }

    private static File createNewFile(String targetFilename)
    throws FileNotFoundException {

        File file = new File(targetFilename);
        String base = null;
        String extension = null;
        if (file.exists()) {
            int n;
            if ((n = targetFilename.lastIndexOf(".")) > targetFilename.lastIndexOf(File.separator)) {
                base = targetFilename.substring(0, n);
                extension = targetFilename.substring(n);
            } else {
                base = targetFilename;
                extension = "";
            }
        }
        for (int i = 1; file.exists(); i++) {
            file = new File(base + "-" + i + extension);
        }
        return file;
    }

    public static void checkOutOfSpace(Exception e, boolean external)
    throws OutOfSpaceError {

        String path;
        if (external) {
            path = Environment.getExternalStorageDirectory().getAbsolutePath();
        } else {
            path = Environment.getDataDirectory().getAbsolutePath();
        }
        StatFs stat = new StatFs(path);
        int available = stat.getAvailableBlocks() * stat.getBlockSize();
        if (available < 8192) {
            throw new OutOfSpaceError(e);
        }
    }

    public static String createOutputDirectory(Context context) {

        File root = new File(Environment.getExternalStorageDirectory(),
                context.getResources().getString(R.string.signature_directory));
        root.mkdirs();
        try {
            new File(root.getAbsolutePath() + File.separator + ".nomedia").createNewFile();
        } catch (IOException e) {
            Log.e(TAG, "Error creating .nomedia file", e);
        }

        CharSequence datePart = DateFormat.format("yyyy-MM-dd_kkmmss", System.currentTimeMillis());
        String output = root.getAbsolutePath() + File.separator + datePart;

        if (new File(output).mkdirs()) {
            return output;
        } else {
            return null;
        }
    }

    public static boolean isPDF(String inputFilename) {

        return inputFilename.toLowerCase().endsWith(".pdf");
    }

    public static boolean containsPDF(Collection<Uri> uris) {

        for (Uri uri : uris) {
            if (isPDF(uri.getPath())) {
                return true;
            }
        }
        return false;
    }

    public static boolean isHiddenOrNotReadable(File f) {

        String name = f.getName();
        boolean notReadable = !f.canRead();
        boolean hidden = name.startsWith(".") && !name.equals(".") && !name.equals("..");
        return notReadable || hidden;
    }
}