package com.sleepless.net.http;

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

public class HTTPDaemon extends Thread
{

	// These can be useful for simulating a slow server.
	// 200 and 100 would probably simulate a 28Kbps connection
	// 200 and 50 would probably simulate a 56Kbps connection
	// A good set of values for normally operations would be 20000 and 0
	// Of course this is just on my PII 400 sony vaio laptop.
	// Other engines will probably vary.
	static final int BUF_SIZE = 20000;
	static final int DELAY = 0;

	void m(String s){System.out.println(getClass().getName()+": "+s);}

	int port;

	public HTTPDaemon(int p)
	{
		port = p;
	}


	public void run()
	{
		try
		{
			m("Listening on port "+port);
			ServerSocket ss = new ServerSocket(port);
			while(true)
			{
				try
				{
					socket = ss.accept();
					startTransaction();
				}
				catch(IOException e)
				{
					m(e.getMessage());
				}
			}
		}
		catch(IOException e)
		{
			e.printStackTrace();
		}
		System.exit(1);
	}


	BufferedReader br;
	BufferedWriter bw;
	Socket socket;
	String firstLine;
	String path;
	int contentLength = 0;
	byte [] content;


	void startTransaction() throws IOException
	{
		InputStreamReader i = new InputStreamReader(socket.getInputStream());
		br = new BufferedReader(i);
		OutputStreamWriter o = new OutputStreamWriter(socket.getOutputStream());
		bw = new BufferedWriter(o);


		firstLine = null;
		path = null;
		contentLength = 0;
		content = null;

		doTransaction();


		flush();
		socket.close();
	}


	String readStr() throws IOException
	{
		String s = br.readLine();
		return s;
	}

	char [] readBytes(int n) throws IOException
	{
		char [] buf = new char[n];
		br.read(buf, 0, n);
		return buf;
	}

	void writeStr(String s) throws IOException
	{
		bw.write(s, 0, s.length());
	}

	void flush() throws IOException
	{
		bw.flush();
	}



	void skipHeaders() throws IOException
	{
		String s;
		while(true)
		{
			s = readStr();
			if(s == null)
				break;
			s = s.trim();
			if(s.equals(""))
				break;

			if(
				s.startsWith("Content-Length: ") || 
				s.startsWith("Content-length: ") ||
				s.startsWith("content-length: ")
				)
			
			{
				contentLength = (int)atol(s.substring(16));
			}
		}

	}



	void doTransaction() throws IOException
	{
		firstLine = readStr();
		if(firstLine == null)
			return;

		path = firstLine;
		int x = path.indexOf(' ');
		if(x == -1)
		{
			defaultTransaction();
			return;
		}
		path = path.substring(x + 1);
		x = path.indexOf(' ');
		if(x == -1)
		{
			defaultTransaction();
			return;
		}
		path = path.substring(0, x);

		int qu = path.indexOf('?');
		if(qu != -1)
		{
			path = path.substring(0, qu);
		}

		skipHeaders();

		// Is it a file?
		String fpath = "./"+path;
		File file = new File(fpath);
		if(file.isFile())
		{
			fileTransaction(file);
			return;
		}

		// No clue.
		defaultTransaction();
	}



	// Return a file to the client.
	void fileTransaction(File file) throws IOException
	{
		// write the http response headers
		writeStr("HTTP/1.0 200 OK\n");
		writeStr("Server: "+getClass().getName()+" 1.0\n");

		// Make some half-hearted attempt to provide a content-type
		String nl = file.getName().toLowerCase();
		if(nl.endsWith(".html"))
			writeStr("Content-Type: text/html\n");
		else
		if(nl.endsWith(".txt"))
			writeStr("Content-Type: text/plain\n");
		else
		if(nl.endsWith(".java"))
			writeStr("Content-Type: text/plain\n");
		else
		if(nl.endsWith(".jpg"))
			writeStr("Content-Type: image/jpeg\n");
		else
		if(nl.endsWith(".bmp"))
			writeStr("Content-Type: image/bmp\n");
		else
		if(nl.endsWith(".jpeg"))
			writeStr("Content-Type: image/jpeg\n");
		else
		if(nl.endsWith(".gif"))
			writeStr("Content-Type: image/gif\n");
		else
		if(nl.endsWith(".hdml"))
			writeStr("Content-Type: text/x-hdml\n");
		else
		if(nl.endsWith(".wml"))
			writeStr("Content-Type: text/vnd.wap.wml\n");
		else
		if(nl.endsWith(".wbmp"))
			writeStr("Content-Type: image/vnd.wap.wbmp\n");
		// write out length
		long len = file.length();
			writeStr("Content-Length: "+len+"\n");

		// separated with a blank line
		writeStr("\n");

		flush();

		// write out the file 
		FileInputStream fis = new FileInputStream(file);
		OutputStream sos = socket.getOutputStream();

		byte [] buf = new byte[BUF_SIZE];
		long n = 0;
		int r;
		while(true)
		{
			r = fis.read(buf);
			if(r == -1)
				break;
			sos.write(buf, 0, r);
			n += r;
			if(DELAY > 0)
			{
				try { Thread.sleep(DELAY); } catch(InterruptedException e) { }
			}
		}

		sos.flush();

		fis.close();
	}


	// Send back "I can't find what you requested" response 
	void defaultTransaction() throws IOException
	{
		String ip = socket.getInetAddress().getHostAddress();

		htmlMsg("<b>HTTPDaemon</b><br>Document not found.", 404);
		flush();			// on your way, my lovelies!
	}


	// Write out a message as an html page.
	void htmlMsg(String msg, int code) throws IOException
	{
		// write the http response headers
		writeStr("HTTP/1.0 "+code+" OK\n");
		writeStr("Server: "+getClass().getName()+" 1.0\n");
		writeStr("Content-Type: text/html\n");

		// separated with a blank line
		writeStr("\n");

		// write out the html 
		writeStr("<html>\n");
		writeStr("<head><title> Hi. </title></head>\n");
		writeStr("<body>\n");
		writeStr( msg+"\n");
		writeStr("</body>\n");
		writeStr("</html>\n");
	}


	static public long atol(String s) 
	{
		long n = 0;
		boolean negate = false;
		for(int i = 0; i < s.length(); i++)
		{
			char c = s.charAt(i);
			if((i == 0) && (c == '-'))
			{
				negate = true;
				continue;
			}
			if(c < '0')
				break;
			if(c > '9')
				break;
			n = (n * 10) + (c - '0');
		}
		if(negate)
			n *= -1;
		return n;
	}



	public static void main(String [] args)
	{
		int p = 80;
		if(args.length > 0)
		{
			p = (int)atol(args[0]);
		}
		new HTTPDaemon(p).start();
	}



}