/*--------------------------------------------------------------------------
    *  Copyright 2007 utgenome.org
    *
    *  Licensed under the Apache License, Version 2.0 (the "License");
    *  you may not use this file except in compliance with the License.
    *  You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *--------------------------------------------------------------------------*/
  //--------------------------------------
  // UTGBMedaka Project
  //
  // WebApplicationResource.java
  // Since: Aug 9, 2007
  //
  // $URL$ 
  // $Author$
  //--------------------------------------
  package org.utgenome.gwt.utgb.server.util;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.StringWriter;
  import java.net.MalformedURLException;
  import java.net.URISyntaxException;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.Set;
  import java.util.regex.Pattern;
  
  import javax.servlet.ServletContext;
  
  import org.xerial.util.FileResource;
  import org.xerial.util.StringUtil;
  import org.xerial.util.log.Logger;
  
  /**
   * Helper class to retrieve web application resources contained in webapp folders (/), /WEB-INF, etc.
   * 
   * @author leo
   *
   */
  public class WebApplicationResource {
  
  	private static Logger _logger = Logger.getLogger(WebApplicationResource.class);
  	
  	private ServletContext _context; 
  	
  	
  	public WebApplicationResource(ServletContext context) 
  	{
  		_context = context;
  	}
  	
  	/**
  	 * Retrieves web application resources from the ServletContext
  	 * @param basePath the resource path, which must begin with "/". For example, "/WEB-INF", "/" etc.  
  	 * @param fileNamePattern the file name pattern
  	 * @param recursive when true, it recursively searches sub folders 
  	 * @return the list of found resource paths
  	 */
  	public ArrayList<String> find(String basePath, String fileNamePattern, boolean recursive)
  	{
  		return find(_context, basePath, fileNamePattern, recursive);
  	}
  	
  	/**
  	 * Retrieves web application resources from the ServletContext
  	 * @param context the servlet context
  	 * @param basePath the resource path, which must begin with "/". For example, "/WEB-INF", "/" etc.  
  	 * @param fileNamePattern the file name pattern
  	 * @param recursive when true, it recursively searches sub folders 
  	 * @return the list of found resource paths
  	 */
  	public static ArrayList<String> find(ServletContext context, String basePath, String fileNamePattern, boolean recursive)
  	{
  		ArrayList<String> foundPath = new ArrayList<String>();
          Set pathSet = context.getResourcePaths(basePath);
          if(pathSet == null)
              return foundPath;
          
          for(Iterator it = pathSet.iterator(); it.hasNext(); )
          {
              String path = it.next().toString();
              URL resource;
  			try {
  				resource = context.getResource(path);
  			} catch (MalformedURLException e) {
 				_logger.error(e);
 				continue;
 			}
 			if(resource == null)
 			    continue;
             if(resource.getPath().endsWith("/") && recursive)
                 foundPath.addAll(find(context, path, fileNamePattern, recursive));
             else
             {
             	if(Pattern.matches(fileNamePattern, resource.getFile())){
             		foundPath.add(path);	
             	}
             }
         }
         return foundPath;
 	}
 
 
 	
 	/**
 	 * Gets a {@link BufferedReader} of the specified web application resource
 	 * @param context the servlet context
 	 * @param path the resource path
 	 * @return a {@link BufferedReader} of the specified resource
 	 * @throws FileNotFoundException when the specified resource is not found
 	 */
 	public static BufferedReader openResource(ServletContext context, String path) throws FileNotFoundException
 	{
 		InputStream in = context.getResourceAsStream(path);
 		if(in == null)
 			throw new FileNotFoundException(path);
 		
 		return new BufferedReader(new InputStreamReader(in));
 		
 	}
 	
 	/**
 	 * @param context the servlet context
 	 * @param path the resource path, which must begin with "/" 
 	 * @return null if the specified resource is not found 
 	 */
 	public static File getResoruceFile(ServletContext context, String path)
 	{
 	    try
         {
             URL resourceURL = context.getResource(path);
             return new File(resourceURL.toURI());
         }
         catch (MalformedURLException e)
         {
             _logger.error(e);
         }
         catch (URISyntaxException e)
         {
             _logger.error(e);
         }
 	    return null;
 	}
 	
 	
 	/**
 	 * Gets a {@link BufferedReader} of the specified web application resource
 	 * @param path the resource path
 	 * @return a {@link BufferedReader} of the specified resource
 	 * @throws FileNotFoundException when the specified resource is not found
 	 */
 	public BufferedReader openResource(String path) throws FileNotFoundException
 	{
 		return openResource(_context, path);
 	}
 	
 	public static String getContent(ServletContext context, String path) throws IOException
 	{
 		BufferedReader reader = openResource(context, path);
 		String line;
 		StringWriter writer = new StringWriter();
 		while((line = reader.readLine()) != null)
 		{
 			writer.append(line);
 			writer.append(StringUtil.newline());
 		}
 		return writer.toString();
 	}
 }