package org.webslinger.servlet;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Enumeration;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import javax.servlet.http.HttpServletRequest;

 import org.apache.commons.fileupload.FileItem;

 import org.apache.commons.fileupload.FileItemFactory;

 import org.apache.commons.fileupload.FileUploadException;

 import org.apache.commons.fileupload.disk.DiskFileItemFactory;

 import org.apache.commons.fileupload.servlet.ServletFileUpload;

 import org.webslinger.io.Charsets;

 import org.webslinger.io.IOUtil;

 public final class MultipartFormUtil {

     private static final FileItemFactory fileItemFactory = new DiskFileItemFactory();

     private MultipartFormUtil() {

     }

     public static FileItem createStringItem(String name, boolean isFormField, String value) throws IOException {

         FileItem item = createFileItem(name, "UTF-8", isFormField, null);

         IOUtil.writeString(item.getOutputStream(), Charsets.UTF8, value);

         return item;

     }

     public static FileItem createFileItem(String name, String contentType, boolean isFormField, String fileName) {

         return fileItemFactory.createItem(name, contentType, isFormField, fileName);

     }

     public static FileItem copyFileItem(FileItem src, String name) throws IOException {

         FileItem dest = fileItemFactory.createItem(name, src.getContentType(), src.isFormField(), src.getName());

         IOUtil.copy(src.getInputStream(), true, dest.getOutputStream(), true);

         return dest;

     }

     public static Map<String, FileItem> filterOutFiles(Map<String, List<FileItem>> items) throws IOException {

         HashMap<String, FileItem> map = new HashMap<String, FileItem>(items.size());

         for (Map.Entry<String, List<FileItem>> entry: items.entrySet()) {

             List<FileItem> values = entry.getValue();

             if (values.get(0).getName() == null) continue;

             map.put(entry.getKey(), values.get(0));

         }

         return map;

     }

     public static Map<String, String> filterOutStrings(Map<String, List<FileItem>> items) throws IOException {

         HashMap<String, String> map = new HashMap<String, String>(items.size());

         for (Map.Entry<String, List<FileItem>> entry: items.entrySet()) {

             List<FileItem> values = entry.getValue();

             if (values.get(0).getName() != null) continue;

             map.put(entry.getKey(), values.get(0).getString("UTF-8"));

         }

         return map;

     }

     public static Map<String, List<FileItem>> parseRequestAsMap(HttpServletRequest request) throws IOException {

         HashMap<String, List<FileItem>> map = (HashMap<String, List<FileItem>>) request.getAttribute(MultipartFormUtil.class.getName() + ".allParametersMap");

         if (map != null) return map;

         List<FileItem> items = parseRequestAsList(request);

         map = new HashMap<String, List<FileItem>>();

         for (FileItem item: items) {

             List<FileItem> values = map.get(item.getFieldName());

             if (values == null) {

                 values = new ArrayList<FileItem>();

                 map.put(item.getFieldName(), values);

             }

             values.add(item);

         }

         request.setAttribute(MultipartFormUtil.class.getName() + ".allParametersMap", map);

         return map;

     }

     public static List<FileItem> parseRequestAsList(HttpServletRequest request) throws IOException {

         ArrayList<FileItem> items = (ArrayList<FileItem>) request.getAttribute(MultipartFormUtil.class.getName() + ".allParametersList");

         if (items != null) return items;

         items = new ArrayList<FileItem>();

         Enumeration en = request.getParameterNames();

         while (en.hasMoreElements()) {

             String name = (String) en.nextElement();

             for (String value: request.getParameterValues(name)) {

                 items.add(createStringItem(name, true, value));

             }

         }

         if (ServletFileUpload.isMultipartContent(request)) {

             ServletFileUpload fileUpload = new ServletFileUpload(fileItemFactory);

             try {

                 items.addAll(fileUpload.parseRequest(request));

             } catch (FileUploadException e) {

                 throw (IOException) new IOException("Couldn't parse request").initCause(e);

             }

         }

         request.setAttribute(MultipartFormUtil.class.getName() + ".allParametersList", items);

         return items;

     }

     public static void disposeOf(Map<String, List<FileItem>> items) throws IOException {

         for (List<FileItem> values: items.values()) {

             disposeOf(values);

         }

     }

     public static void disposeOf(List<FileItem> items) throws IOException {

         for (FileItem item: items) {

             item.delete();

         }

     }

 }