// This code is provided "as is" with NO WARRANTY expressed or 
// implied. You may use it freely at your own risk.

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

public class Kevin {
	public static int getContentLen(String line) throws NumberFormatException {
		String l = line.substring(line.indexOf(": ") + 2 );
		return (Integer.parseInt(l));
	}

	public static void main(String args[]) {

	try {
		int port = Integer.parseInt(args[0]);
		System.out.println("Implementing on port " + port);
		ServerSocket ss = new ServerSocket(port);
		System.out.println("Server Socket initialized");
		String protocol = "";
		String filename = "";
		for(;;) {
  		 	Socket client = ss.accept();
			System.out.println("Got a request");
			BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
			PrintWriter out = new PrintWriter(new OutputStreamWriter(client.getOutputStream()));

			out.println("HTTP/1.0 200 ");             
			out.println("Content-Type: text/html"); 
			out.println();                          
			String line;
			int cLen = 0;
			while ((line = in.readLine()) != null) {
				System.out.println(line);
				if (line.indexOf("GET") >= 0) {
					protocol = "get";
					filename = Kevin.getFileName(line);
				}
				// out.println(line);
				if (line.indexOf("ength: ") >= 0) {
					cLen = Kevin.getContentLen(line);
				} 
				if (line.length() == 0) break;
			}
			if (cLen > 0) {
				char[] buffer = new char[cLen];
				in.read(buffer, 0, cLen);
				line = new String(buffer);
				// out.println(line);
			}
			if (protocol.compareTo("get") == 0) {
				try {
					BufferedReader getter = new BufferedReader(new FileReader(filename));
					while ((line = getter.readLine()) != null)	{
						out.println(line);
					}
				}
				catch(Exception any) {
					System.out.println("Error reading get file: " + any.getMessage());
				}
			}
			out.flush();
	   	out.close();
      	in.close();
	   	client.close();
		}
    }
    catch (NumberFormatException n) {
      System.err.println(n);
    }
    catch (Exception e) {
      System.err.println(e);
    }
  }
  
	public static String getFileName(String line) {
		StringTokenizer st = new StringTokenizer(line);
		String fn = "";
		int count = 0;
		while (st.hasMoreTokens()) {
			count++;
			if (count == 2) {
				return st.nextToken();
			}
			else fn = st.nextToken();
		}
		return "";
	}
}