package de.kreth.invoice.report;

import java.io.File;
import java.io.FileFilter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Objects;

import org.apache.commons.io.FilenameUtils;

import de.kreth.invoice.data.User;

public class Signature {

    private final User user;

    public Signature(User user) {
	super();
	this.user = Objects.requireNonNull(user);
    }

    public OutputStream createOutputStream(String fileName) throws IOException {
	File dir = new File("images");
	dir.mkdirs();
	return new FileOutputStream(new File(dir, user.getId() + "." + FilenameUtils.getExtension(fileName)));
    }

    public boolean isSignatureImageExists() {
	File[] listFiles = new File("images").listFiles(new FileFilter() {

	    @Override
	    public boolean accept(File pathname) {
		return pathname.getName().startsWith(user.getId() + ".");
	    }
	});
	return listFiles != null && listFiles.length > 0;
    }

    /**
     * Check with {@link #isSignatureImageExists()} existence first.
     *
     * @return
     * @throws NullPointerException if image does not exist.
     */
    public File getSignatureUrl() {
	File[] listFiles = new File("images").listFiles(new FileFilter() {

	    @Override
	    public boolean accept(File pathname) {
		return pathname.getName().startsWith(user.getId() + ".");
	    }
	});
	if (listFiles == null || listFiles.length == 0) {
	    throw new NullPointerException("Image file does not exist");
	}
	return listFiles[0];
    }
}