package it.polito.appeal.traci.test;

import java.io.*;
import java.util.*;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.net.*;

/**
 * A simple, tiny, nicely embeddable HTTP 1.0 server in Java
 *
 * <p> NanoHTTPD version 1.12,
 * Copyright &copy; 2001,2005-2010 Jarno Elonen (elonen@iki.fi, http://iki.fi/elonen/)
 *
 * <p><b>Features + limitations: </b><ul>
 *
 *    <li> Only one Java file </li>
 *    <li> Java 1.1 compatible </li>
 *    <li> Released as open source, Modified BSD licence </li>
 *    <li> No fixed config files, logging, authorization etc. (Implement yourself if you need them.) </li>
 *    <li> Supports parameter parsing of GET and POST methods </li>
 *    <li> Supports both dynamic content and file serving </li>
 *    <li> Never caches anything </li>
 *    <li> Doesn't limit bandwidth, request time or simultaneous connections </li>
 *    <li> Default code serves files and shows all HTTP parameters and headers</li>
 *    <li> File server supports directory listing, index.html and index.htm </li>
 *    <li> File server does the 301 redirection trick for directories without '/'</li>
 *    <li> File server supports simple skipping for files (continue download) </li>
 *    <li> File server uses current directory as a web root </li>
 *    <li> File server serves also very long files without memory overhead </li>
 *    <li> Contains a built-in list of most common mime types </li>
 *    <li> All header names are converted lowercase so they don't vary between browsers/clients </li>
 *
 * </ul>
 *
 * <p><b>Ways to use: </b><ul>
 *
 *    <li> Run as a standalone app, serves files from current directory and shows requests</li>
 *    <li> Subclass serve() and embed to your own program </li>
 *    <li> Call serveFile() from serve() with your own base directory </li>
 *
 * </ul>
 *
 * See the end of the source file for distribution license
 * (Modified BSD licence)
 */
@SuppressWarnings("javadoc")
public class NanoHTTPD
{
	private Logger log = LogManager.getLogger();

	// ==================================================
	// API parts
	// ==================================================

	/**
	 * Override this to customize the server.<p>
	 *
	 * (By default, this delegates to serveFile() and allows directory listing.)
	 *
	 * @parm uri	Percent-decoded URI without parameters, for example "/index.cgi"
	 * @parm method	"GET", "POST" etc.
	 * @parm parms	Parsed, percent decoded parameters from URI and, in case of POST, data.
	 * @parm header	Header entries, percent decoded
	 * @return HTTP response, see class Response for details
	 */
	public Response serve( String uri, String method, Properties header, Properties parms )
	{
		log.debug( method + " '" + uri + "' " );

		Enumeration<?> e = header.propertyNames();
		while ( e.hasMoreElements())
		{
			String value = (String)e.nextElement();
			log.debug( "  HDR: '" + value + "' = '" +
								header.getProperty( value ) + "'" );
		}
		e = parms.propertyNames();
		while ( e.hasMoreElements())
		{
			String value = (String)e.nextElement();
			log.debug( "  PRM: '" + value + "' = '" +
								parms.getProperty( value ) + "'" );
		}

		return serveFile( uri, header, new File("."), true );
	}

	/**
	 * HTTP response.
	 * Return one of these from serve().
	 */
	public class Response
	{
		/**
		 * Default constructor: response = HTTP_OK, data = mime = 'null'
		 */
		public Response()
		{
			this.status = HTTP_OK;
		}

		/**
		 * Basic constructor.
		 */
		public Response( String status, String mimeType, InputStream data )
		{
			this.status = status;
			this.mimeType = mimeType;
			this.data = data;
		}

		/**
		 * Convenience method that makes an InputStream out of
		 * given text.
		 */
		public Response( String status, String mimeType, String txt )
		{
			this.status = status;
			this.mimeType = mimeType;
			this.data = new ByteArrayInputStream( txt.getBytes());
		}

		/**
		 * Adds given line to the header.
		 */
		public void addHeader( String name, String value )
		{
			header.put( name, value );
		}

		/**
		 * HTTP status code after processing, e.g. "200 OK", HTTP_OK
		 */
		public String status;

		/**
		 * MIME type of content, e.g. "text/html"
		 */
		public String mimeType;

		/**
		 * Data of the response, may be null.
		 */
		public InputStream data;

		/**
		 * Headers for the HTTP response. Use addHeader()
		 * to add lines.
		 */
		public Properties header = new Properties();
	}

	/**
	 * Some HTTP response status codes
	 */
	public static final String
		HTTP_OK = "200 OK",
		HTTP_REDIRECT = "301 Moved Permanently",
		HTTP_FORBIDDEN = "403 Forbidden",
		HTTP_NOTFOUND = "404 Not Found",
		HTTP_BADREQUEST = "400 Bad Request",
		HTTP_INTERNALERROR = "500 Internal Server Error",
		HTTP_NOTIMPLEMENTED = "501 Not Implemented";

	/**
	 * Common mime types for dynamic content
	 */
	public static final String
		MIME_PLAINTEXT = "text/plain",
		MIME_HTML = "text/html",
		MIME_DEFAULT_BINARY = "application/octet-stream";

	// ==================================================
	// Socket & server code
	// ==================================================

	/**
	 * Starts a HTTP server to given port.<p>
	 * Throws an IOException if the socket is already in use
	 */
	public NanoHTTPD( int port ) throws IOException
	{
		myTcpPort = port;

		@SuppressWarnings("resource")
		final ServerSocket ss = new ServerSocket( myTcpPort );
		Thread t = new Thread( new Runnable()
			{
				public void run()
				{
					try
					{
						while( true )
							new HTTPSession( ss.accept());
					}
					catch ( IOException ioe )
					{
						log.error(ioe);
					}
				}
			});
		t.setDaemon( true );
		t.start();
	}

	/**
	 * Starts as a standalone file server and waits for Enter.
	 */
	public static void main( String[] args )
	{
		System.out.println( "NanoHTTPD 1.12 (C) 2001,2005-2010 Jarno Elonen\n" +
							"(Command line options: [port] [--licence])\n" );

		// Show licence if requested
		int lopt = -1;
		for ( int i=0; i<args.length; ++i )
		if ( args[i].toLowerCase().endsWith( "licence" ))
		{
			lopt = i;
			System.out.println( LICENCE + "\n" );
		}

		// Change port if requested
		int port = 80;
		if ( args.length > 0 && lopt != 0 )
			port = Integer.parseInt( args[0] );

		if ( args.length > 1 &&
			 args[1].toLowerCase().endsWith( "licence" ))
				System.out.println( LICENCE + "\n" );

		NanoHTTPD nh = null;
		try
		{
			nh = new NanoHTTPD( port );
		}
		catch( IOException ioe )
		{
			System.err.println( "Couldn't start server:\n" + ioe );
			System.exit( -1 );
		}
		nh.myFileDir = new File("");

		System.out.println( "Now serving files in port " + port + " from \"" +
							new File("").getAbsolutePath() + "\"" );
		System.out.println( "Hit Enter to stop.\n" );

		try { System.in.read(); } catch( Throwable t ) {};
	}

	/**
	 * Handles one session, i.e. parses the HTTP request
	 * and returns the response.
	 */
	private class HTTPSession implements Runnable
	{
		public HTTPSession( Socket s )
		{
			mySocket = s;
			Thread t = new Thread( this );
			t.setDaemon( true );
			t.start();
		}

		public void run()
		{
			try
			{
				InputStream is = mySocket.getInputStream();
				if ( is == null) return;
				BufferedReader in = new BufferedReader( new InputStreamReader( is ));

				// Read the request line
				String inLine = in.readLine();
				if (inLine == null) return;
				StringTokenizer st = new StringTokenizer( inLine );
				if ( !st.hasMoreTokens())
					sendError( HTTP_BADREQUEST, "BAD REQUEST: Syntax error. Usage: GET /example/file.html" );

				String method = st.nextToken();

				if ( !st.hasMoreTokens())
					sendError( HTTP_BADREQUEST, "BAD REQUEST: Missing URI. Usage: GET /example/file.html" );

				String uri = st.nextToken();

				// Decode parameters from the URI
				Properties parms = new Properties();
				int qmi = uri.indexOf( '?' );
				if ( qmi >= 0 )
				{
					decodeParms( uri.substring( qmi+1 ), parms );
					uri = decodePercent( uri.substring( 0, qmi ));
				}
				else uri = decodePercent(uri);


				// If there's another token, it's protocol version,
				// followed by HTTP headers. Ignore version but parse headers.
				// NOTE: this now forces header names uppercase since they are
				// case insensitive and vary by client.
				Properties header = new Properties();
				if ( st.hasMoreTokens())
				{
					String line = in.readLine();
					while ( line.trim().length() > 0 )
					{
						int p = line.indexOf( ':' );
						header.put( line.substring(0,p).trim().toLowerCase(), line.substring(p+1).trim());
						line = in.readLine();
					}
				}

				// If the method is POST, there may be parameters
				// in data section, too, read it:
				if ( method.equalsIgnoreCase( "POST" ))
				{
					long size = 0x7FFFFFFFFFFFFFFFl;
					String contentLength = header.getProperty("content-length");
					if (contentLength != null)
					{
						try { size = Integer.parseInt(contentLength); }
						catch (NumberFormatException ex) { log.error(ex); }
					}
					String postLine = "";
					char buf[] = new char[512];
					int read = in.read(buf);
					while ( read >= 0 && size > 0 && !postLine.endsWith("\r\n") )
					{
						size -= read;
						postLine += String.valueOf(buf, 0, read);
						if ( size > 0 )
							read = in.read(buf);
					}
					postLine = postLine.trim();
					decodeParms( postLine, parms );
				}

				// Ok, now do the serve()
				Response r = serve( uri, method, header, parms );
				if ( r == null )
					sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: Serve() returned a null response." );
				else
					sendResponse( r.status, r.mimeType, r.header, r.data );

				in.close();
			}
			catch ( IOException ioe )
			{
				try
				{
					sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
				}
				catch ( Throwable t ) {}
			}
			catch ( InterruptedException ie )
			{
				// Thrown by sendError, ignore and exit the thread.
			}
		}

		/**
		 * Decodes the percent encoding scheme. <br/>
		 * For example: "an+example%20string" -> "an example string"
		 */
		private String decodePercent( String str ) throws InterruptedException
		{
			try
			{
				StringBuffer sb = new StringBuffer();
				for( int i=0; i<str.length(); i++ )
				{
				    char c = str.charAt( i );
				    switch ( c )
					{
				        case '+':
				            sb.append( ' ' );
				            break;
				        case '%':
			                sb.append((char)Integer.parseInt( str.substring(i+1,i+3), 16 ));
				            i += 2;
				            break;
				        default:
				            sb.append( c );
				            break;
				    }
				}
				return new String( sb.toString().getBytes());
			}
			catch( Exception e )
			{
				sendError( HTTP_BADREQUEST, "BAD REQUEST: Bad percent-encoding." );
				return null;
			}
		}

		/**
		 * Decodes parameters in percent-encoded URI-format
		 * ( e.g. "name=Jack%20Daniels&pass=Single%20Malt" ) and
		 * adds them to given Properties. NOTE: this doesn't support multiple
		 * identical keys due to the simplicity of Properties -- if you need multiples,
		 * you might want to replace the Properties with a Hastable of Vectors or such.
		 */
		private void decodeParms( String parms, Properties p )
			throws InterruptedException
		{
			if ( parms == null )
				return;

			StringTokenizer st = new StringTokenizer( parms, "&" );
			while ( st.hasMoreTokens())
			{
				String e = st.nextToken();
				int sep = e.indexOf( '=' );
				if ( sep >= 0 )
					p.put( decodePercent( e.substring( 0, sep )).trim(),
						   decodePercent( e.substring( sep+1 )));
			}
		}

		/**
		 * Returns an error message as a HTTP response and
		 * throws InterruptedException to stop furhter request processing.
		 */
		private void sendError( String status, String msg ) throws InterruptedException
		{
			sendResponse( status, MIME_PLAINTEXT, null, new ByteArrayInputStream( msg.getBytes()));
			throw new InterruptedException();
		}

		/**
		 * Sends given response to the socket.
		 */
		private void sendResponse( String status, String mime, Properties header, InputStream data )
		{
			try
			{
				if ( status == null )
					throw new Error( "sendResponse(): Status can't be null." );

				OutputStream out = mySocket.getOutputStream();
				PrintWriter pw = new PrintWriter( out );
				pw.print("HTTP/1.0 " + status + " \r\n");

				if ( mime != null )
					pw.print("Content-Type: " + mime + "\r\n");

				if ( header == null || header.getProperty( "Date" ) == null )
					pw.print( "Date: " + gmtFrmt.format( new Date()) + "\r\n");

				if ( header != null )
				{
					Enumeration<?> e = header.keys();
					while ( e.hasMoreElements())
					{
						String key = (String)e.nextElement();
						String value = header.getProperty( key );
						pw.print( key + ": " + value + "\r\n");
					}
				}

				pw.print("\r\n");
				pw.flush();

				if ( data != null )
				{
					byte[] buff = new byte[2048];
					while (true)
					{
						int read = data.read( buff, 0, 2048 );
						if (read <= 0)
							break;
						out.write( buff, 0, read );
					}
				}
				out.flush();
				out.close();
				if ( data != null )
					data.close();
			}
			catch( IOException ioe )
			{
				// Couldn't write? No can do.
				try { mySocket.close(); } catch( Throwable t ) {}
			}
		}

		private Socket mySocket;
	};

	/**
	 * URL-encodes everything between "/"-characters.
	 * Encodes spaces as '%20' instead of '+'.
	 */
	private String encodeUri( String uri )
	{
		String newUri = "";
		StringTokenizer st = new StringTokenizer( uri, "/ ", true );
		while ( st.hasMoreTokens())
		{
			String tok = st.nextToken();
			if ( tok.equals( "/" ))
				newUri += "/";
			else if ( tok.equals( " " ))
				newUri += "%20";
			else
			{
				// newUri += URLEncoder.encode( tok );
				// For Java 1.4 you'll want to use this instead:
				try { 
					newUri += URLEncoder.encode( tok, "UTF-8" ); 
					} 
				catch ( UnsupportedEncodingException uee ) {assert false;}
			}
		}
		return newUri;
	}

	private int myTcpPort;
	File myFileDir;

	// ==================================================
	// File server code
	// ==================================================

	/**
	 * Serves file from homeDir and its' subdirectories (only).
	 * Uses only URI, ignores all headers and HTTP parameters.
	 */
	public Response serveFile( String uri, Properties header, File homeDir,
							   boolean allowDirectoryListing )
	{
		// Make sure we won't die of an exception later
		if ( !homeDir.isDirectory())
			return new Response( HTTP_INTERNALERROR, MIME_PLAINTEXT,
								 "INTERNAL ERRROR: serveFile(): given homeDir is not a directory." );

		// Remove URL arguments
		uri = uri.trim().replace( File.separatorChar, '/' );
		if ( uri.indexOf( '?' ) >= 0 )
			uri = uri.substring(0, uri.indexOf( '?' ));

		// Prohibit getting out of current directory
		if ( uri.startsWith( ".." ) || uri.endsWith( ".." ) || uri.indexOf( "../" ) >= 0 )
			return new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT,
								 "FORBIDDEN: Won't serve ../ for security reasons." );

		File f = new File( homeDir, uri );
		if ( !f.exists())
			return new Response( HTTP_NOTFOUND, MIME_PLAINTEXT,
								 "Error 404, file not found." );

		// List the directory, if necessary
		if ( f.isDirectory())
		{
			// Browsers get confused without '/' after the
			// directory, send a redirect.
			if ( !uri.endsWith( "/" ))
			{
				uri += "/";
				Response r = new Response( HTTP_REDIRECT, MIME_HTML,
										   "<html><body>Redirected: <a href=\"" + uri + "\">" +
										   uri + "</a></body></html>");
				r.addHeader( "Location", uri );
				return r;
			}

			// First try index.html and index.htm
			if ( new File( f, "index.html" ).exists())
				f = new File( homeDir, uri + "/index.html" );
			else if ( new File( f, "index.htm" ).exists())
				f = new File( homeDir, uri + "/index.htm" );

			// No index file, list the directory
			else if ( allowDirectoryListing )
			{
				String[] files = f.list();
				String msg = "<html><body><h1>Directory " + uri + "</h1><br/>";

				if ( uri.length() > 1 )
				{
					String u = uri.substring( 0, uri.length()-1 );
					int slash = u.lastIndexOf( '/' );
					if ( slash >= 0 && slash  < u.length())
						msg += "<b><a href=\"" + uri.substring(0, slash+1) + "\">..</a></b><br/>";
				}

				for ( int i=0; i<files.length; ++i )
				{
					File curFile = new File( f, files[i] );
					boolean dir = curFile.isDirectory();
					if ( dir )
					{
						msg += "<b>";
						files[i] += "/";
					}

					msg += "<a href=\"" + encodeUri( uri + files[i] ) + "\">" +
						   files[i] + "</a>";

					// Show file size
					if ( curFile.isFile())
					{
						long len = curFile.length();
						msg += " &nbsp;<font size=2>(";
						if ( len < 1024 )
							msg += curFile.length() + " bytes";
						else if ( len < 1024 * 1024 )
							msg += curFile.length()/1024 + "." + (curFile.length()%1024/10%100) + " KB";
						else
							msg += curFile.length()/(1024*1024) + "." + curFile.length()%(1024*1024)/10%100 + " MB";

						msg += ")</font>";
					}
					msg += "<br/>";
					if ( dir ) msg += "</b>";
				}
				return new Response( HTTP_OK, MIME_HTML, msg );
			}
			else
			{
				return new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT,
								 "FORBIDDEN: No directory listing." );
			}
		}

		try
		{
			// Get MIME type from file name extension, if possible
			String mime = null;
			int dot = f.getCanonicalPath().lastIndexOf( '.' );
			if ( dot >= 0 )
				mime = (String)theMimeTypes.get( f.getCanonicalPath().substring( dot + 1 ).toLowerCase());
			if ( mime == null )
				mime = MIME_DEFAULT_BINARY;

			// Support (simple) skipping:
			long startFrom = 0;
			String range = header.getProperty( "Range" );
			if ( range != null )
			{
				if ( range.startsWith( "bytes=" ))
				{
					range = range.substring( "bytes=".length());
					int minus = range.indexOf( '-' );
					if ( minus > 0 )
						range = range.substring( 0, minus );
					try	{
						startFrom = Long.parseLong( range );
					}
					catch ( NumberFormatException nfe ) {log.error(nfe);}
				}
			}

			FileInputStream fis = new FileInputStream( f );
			fis.skip( startFrom );
			Response r = new Response( HTTP_OK, mime, fis );
			r.addHeader( "Content-length", "" + (f.length() - startFrom));
			r.addHeader( "Content-range", "" + startFrom + "-" +
						(f.length()-1) + "/" + f.length());
			return r;
		}
		catch( IOException ioe )
		{
			return new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Reading file failed." );
		}
	}

	/**
	 * Hashtable mapping (String)FILENAME_EXTENSION -> (String)MIME_TYPE
	 */
	private static Hashtable<String, String> theMimeTypes = new Hashtable<String, String>();
	static
	{
		StringTokenizer st = new StringTokenizer(
			"htm		text/html "+
			"html		text/html "+
			"txt		text/plain "+
			"asc		text/plain "+
			"gif		image/gif "+
			"jpg		image/jpeg "+
			"jpeg		image/jpeg "+
			"png		image/png "+
			"mp3		audio/mpeg "+
			"m3u		audio/mpeg-url " +
			"pdf		application/pdf "+
			"doc		application/msword "+
			"ogg		application/x-ogg "+
			"zip		application/octet-stream "+
			"exe		application/octet-stream "+
			"class		application/octet-stream " );
		while ( st.hasMoreTokens())
			theMimeTypes.put( st.nextToken(), st.nextToken());
	}

	/**
	 * GMT date formatter
	 */
    private static java.text.SimpleDateFormat gmtFrmt;
	static
	{
		gmtFrmt = new java.text.SimpleDateFormat( "E, d MMM yyyy HH:mm:ss 'GMT'", Locale.US);
		gmtFrmt.setTimeZone(TimeZone.getTimeZone("GMT"));
	}

	/**
	 * The distribution licence
	 */
	private static final String LICENCE =
		"Copyright (C) 2001,2005-2008 by Jarno Elonen <elonen@iki.fi>\n"+
		"\n"+
		"Redistribution and use in source and binary forms, with or without\n"+
		"modification, are permitted provided that the following conditions\n"+
		"are met:\n"+
		"\n"+
		"Redistributions of source code must retain the above copyright notice,\n"+
		"this list of conditions and the following disclaimer. Redistributions in\n"+
		"binary form must reproduce the above copyright notice, this list of\n"+
		"conditions and the following disclaimer in the documentation and/or other\n"+
		"materials provided with the distribution. The name of the author may not\n"+
		"be used to endorse or promote products derived from this software without\n"+
		"specific prior written permission. \n"+
		" \n"+
		"THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"+
		"IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\n"+
		"OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\n"+
		"IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\n"+
		"INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\n"+
		"NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\n"+
		"DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\n"+
		"THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\n"+
		"(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE\n"+
		"OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.";
}
