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

public class Server implements Runnable
{
	public static ServerSocket echoServer = null;
	Thread t=new Thread(this);

	Socket clientSocket = null;

	String dirName="C:\\Users\\User\\Desktop\\Offline";
	String [] allowedExt = { ".java",".py" };
    int portNumber = 1234 ;
    String line;

	ArrayList <ClientThread> clients = new ArrayList();
	int clientCount=0;

	public void print(String s) //Defined macro-type function
	{
		System.out.println(s);
	}

	Server()
	{
		try
	    {
	    	echoServer = new ServerSocket(portNumber);
	    	System.out.println("The server has started at port " + portNumber);
	    	t.start();
	    }
	    catch(Exception e)
	    {
	    	System.out.println(e.toString());
	    }
	}

	public void run()
	{
		while(true)
    	{
    		print("Amount of clients: "+ clientCount);
    		try
    		{
				addThread(echoServer.accept());
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
    	}
	}

	public void addThread(Socket sock)
	{
		clientCount++;
		print("Client number "+clientCount + " just got connected!");
		clients.add(new Server.ClientThread(this,sock));  //creates new thread of new client
	}

	class ClientThread extends Thread
	{
		//variables for the working thread
		Server serv;
		Socket socket = null;
	    String portName = "localhost" ;
	    int portNumber=1234;
	    public final static int FILE_SIZE = 6022386; // file size temporary hard coded

	    BufferedReader br;
	    PrintWriter bw;

		ClientThread(Server s, Socket c) //constructor
		{
			serv=s; socket=c;

			try
			{
	  	      	br=new BufferedReader( new InputStreamReader(socket.getInputStream()) );
	    		bw = new PrintWriter(socket.getOutputStream());

	  	      	//now the main work
	  	      	start();

			}
			catch (IOException e)
			{
				e.printStackTrace();
			}

		}

		public void close()
		{
			try
			{
				bw.close();
				socket.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		public void receiveFile(String fileName, String dirName)
		{
			//print("received file <fake>");
			try
			{
		        InputStream is = socket.getInputStream();
		        FileOutputStream fos = new FileOutputStream(dirName+"\\"+fileName);
		        BufferedOutputStream bos = new BufferedOutputStream(fos);

		        //byte[] buffer = new byte[socket.getReceiveBufferSize()];
		        byte[] buffer = new byte[512];

		        int bytesReceived = 0;

		        while((bytesReceived = is.read(buffer))>0)
		        {
		            /* Write to the file */
		           bos.write(buffer,0,bytesReceived);
		           bos.flush();
		        }

		        bos.flush();
		        fos.flush();
		        bos.close();
		        fos.close();
			}
			catch(Exception e)
			{
				print(e.toString());
			}

		}

		public void run()
		{
			System.out.println("Connected to a client!");
    		bw.write("Hello from FTP Server"+"\n");
			bw.flush();

			String line;
			try
			{
				print("Getting input from client...");
				line=br.readLine();

				while(true)
				{
					print("Client says: "+line);

					File f1=new File(dirName);
					File fileList [] = f1.listFiles();

					Arrays.sort(fileList);

					int fileCount=0;
					boolean found=false;
					boolean extOK=false;
					String fileExt;
					String fileName=line;  //1005047.java

					//checking if file extension matches
					for(int i=0;i<allowedExt.length;i++)
					{
						print("checking "+fileName+ " with " + allowedExt[i]);
						if(fileName.endsWith(allowedExt[i]))
						{
							extOK=true;
							break;
						}
					}

					//checking if file exists
					for(int i=0;i<fileList.length;i++)
					{
						if(fileList[i].canRead())
						{
							fileCount++;
							String fName=fileList[i].getName();

							int pos=fName.indexOf(".");

							fileExt=fName.substring(pos+1);
							print("File name: "+fName +", Ext: "+fileExt + ", File Size:" +fileList[i].length() + "bytes");
							if(fName.equals(line)) found = true;
						}
					}

					print(fileCount + " files found.");
					if(found && extOK)
					{
						print("SEARCHED FILE PRESENT!");
						bw.write("present"+"\n");
						bw.flush();

						line=br.readLine();//response if client wants to send file
						if(line.equals("y"))
						{
							receiveFile(fileName,dirName);
							//break;
						}
					}
					else
					{
						print("SEARCH NOT FOUND");
						bw.write("no"+"\n");
						bw.flush();

						line=br.readLine();//response if client wants to send file
						if(line.equals("y"))
						{
							receiveFile(fileName,dirName);
							//break;
						}
					}

					line=br.readLine();
					if(line.equals("q"))
					{
						print("This user is quitting...");
						break;
					}
				}
				close();


			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.toString();
			}
		}
	}


	public static void main(String[] args)
	{
	    Server s=new Server();
	}

}