package com.sirma.customs.ems21.web.fileupload;

import java.io.Closeable;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

/**
 * Accepts the request passed from the sign applet. There should be two
 * parameters: a file and filename (string). The file is then written in a temp
 * directory to be used from action class. And filename is stored in
 * servletContext as attribute - it is needed because the filename contains a
 * timestamp part appended on creation time and we doesn't know what is it
 * exactly.
 *
 * @author svelikov
 */
public class FileUploaderServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    private static final int SIZE_THRESHOLD = 1024 * 1024 * 10; // 10MB

    /**
     * Default constructor.
     */
    public FileUploaderServlet() {
        super();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        processRequest(req, resp);
    }

    /**
     * Process the request.
     *
     * @param req
     *            HttpServletRequest.
     * @param resp
     *            HttpServletResponse.
     */
    public void processRequest(HttpServletRequest req, HttpServletResponse resp) {
        boolean isMultipart = ServletFileUpload.isMultipartContent(req);
        String tempFilePath = getServletContext().getAttribute("javax.servlet.context.tempdir") + "/";

        if (isMultipart) {
            String fullFileName;

            // Create a factory for disk-based file items
            FileItemFactory factory = new DiskFileItemFactory(SIZE_THRESHOLD, new File(tempFilePath));

            // Create a new file upload handler
            ServletFileUpload upload = new ServletFileUpload(factory);
            FileOutputStream fos = null;
            try {
                List<FileItem> items = upload.parseRequest(req);
                for (FileItem item : items) {
                    if (item.isFormField()) {
                        // we haven't form fields set in the request
                    } else {
                        String signedFilePath = tempFilePath + item.getName();
                        fos = new FileOutputStream(signedFilePath);
                        InputStream fileStream = item.getInputStream();
                        int current = 0;
                        while ((current = fileStream.read()) != -1) {
                            fos.write(current);
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                close(fos);
            }
        }
    }

    /**
     * Closes provided stream.
     *
     * @param stream
     *            The stream to be closed.
     */
    private void close(Closeable stream) {
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}