package com.mentor.markups.server.servlet.service;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
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.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class SendServiceImpl extends HttpServlet{

	  // location to store file uploaded
    private static final String UPLOAD_DIRECTORY = "upload";

    // upload settings
    private static final int MEMORY_THRESHOLD   = 1024 * 1024 * 3;  // 3MB
    private static final int MAX_FILE_SIZE      = 1024 * 1024 * 40; // 40MB
    private static final int MAX_REQUEST_SIZE   = 1024 * 1024 * 50; // 50MB

	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		 if (!ServletFileUpload.isMultipartContent(request)) {
	            // if not, we stop here
	            PrintWriter writer = response.getWriter();
	            writer.println("Error: Form must has enctype=multipart/form-data.");
	            writer.flush();
	            return;
	        }
		 	// configures upload settings
	        DiskFileItemFactory factory = new DiskFileItemFactory();
	        // sets memory threshold - beyond which files are stored in disk
	        factory.setSizeThreshold(MEMORY_THRESHOLD);
	        // sets temporary location to store files
	        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

	        ServletFileUpload upload = new ServletFileUpload(factory);

	        // sets maximum size of upload file
	        upload.setFileSizeMax(MAX_FILE_SIZE);

	        // sets maximum size of request (include file + form data)
	        upload.setSizeMax(MAX_REQUEST_SIZE);

	        // constructs the directory path to store upload file
	        // this path is relative to application's directory
	        String uploadPath = getServletContext().getRealPath("")
	                + File.separator + UPLOAD_DIRECTORY;

	        // creates the directory if it does not exist
	        File uploadDir = new File(uploadPath);
	        if (!uploadDir.exists()) {
	            uploadDir.mkdir();
	        }

	        try {
	            // parses the request's content to extract file data
	            @SuppressWarnings("unchecked")
	            List<FileItem> formItems = upload.parseRequest(request);

	            if (formItems != null && formItems.size() > 0) {
	                // iterates over form's fields
	                for (FileItem item : formItems) {
	                    // processes only fields that are not form fields
	                    if (!item.isFormField()) {
	                        String fileName = new File(item.getName()).getName();
	                        String filePath = uploadPath + File.separator + fileName;
	                        File storeFile = new File(filePath);

	                        // saves the file on disk
	                        item.write(storeFile);
	                        request.setAttribute("message",
	                            "Upload has been done successfully!");
	                    }
	                }
	            }
	        } catch (Exception ex) {
	            request.setAttribute("message",
	                    "There was an error: " + ex.getMessage());
	        }
	        // redirects client to message page
	        getServletContext().getRequestDispatcher("/").forward(request, response);

	}

}