import java.awt.BorderLayout;
import java.net.*;
import java.util.ArrayList;
import java.util.regex.Pattern;
import java.io.*;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class ChatServer implements Runnable {
	private ChatServerThread clients[] = new ChatServerThread[50];
	private ServerSocket serverSocket = null;
	private Thread t = null;
	private int noOfClients = 0;
	private JTextArea chatField;
	private JTextField typeField;

	public ChatServer(int port) {
		JFrame frame;
		typeField = new JTextField(160);
		chatField = new JTextArea();

		frame = new JFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setLayout(new BorderLayout());
		frame.setTitle("Server");
		frame.setSize(500, 300);

		frame.add(chatField, BorderLayout.CENTER);

		chatField.setEditable(false);
		frame.setVisible(true);

		try {
			System.out.println("Binding to port " + port + ", please wait  ...");
			chatField.setText(chatField.getText() + "\nBinding to port " + port + ", please wait  ...");
			serverSocket = new ServerSocket(port);
			System.out.println("serverSocket started: " + serverSocket);
			chatField.setText(chatField.getText() + "\nserverSocket started: " + serverSocket);
			start();
		} catch (IOException ioe) {
			chatField.setText(chatField.getText() + ("Can not bind to port " + port + ": " + ioe.getMessage()));
			System.out.println("Can not bind to port " + port + ": " + ioe.getMessage());
		}

	}

	public void run() {
		while (t != null) {
			try {
				System.out.println("Waiting for a client ...");
				chatField.setText(chatField.getText() + "\nWaiting for a client ...");
				addThread(serverSocket.accept());
			} catch (IOException ioe) {
				System.out.println("serverSocket accept error: " + ioe);
				stop();
			}
		}
	}

	public void start() {
		if (t == null) {
			t = new Thread(this);
			t.start();
		}
	}

	public void stop() {
		if (t != null) {
			t.stop();
			t = null;
		}
	}

	private int findClient(int ID) {
		for (int i = 0; i < noOfClients; i++)
			if (clients[i].getID() == ID)
				return i;
		return -1;
	}

	public synchronized void handle(int ID, String input) {
		ChatServerThread client = clients[findClient(ID)];
		String userName = null, password = null, message = null;
		if (input.contains(".register")) {
			System.out.println("Registering " + input);
			String parsedInfo[] = input.split(Pattern.quote(" "));
			userName = parsedInfo[1];
			password = parsedInfo[2];
			registerUser(userName, password);
		} else if (input.contains(".login")) {
			String parsedInfo[] = input.split(Pattern.quote(" "));
			userName = parsedInfo[1];
			password = parsedInfo[2];
			if (checkLogin(userName, password) == false) {
				System.out.println("Telling user " + userName + " to register");
				client.send(".register");
			}
			client.send("SERVER: Login successful, welcome " + userName);
		} else if (input.charAt(0) != '.') {
			System.out.println(input);
			String parsedInfo[] = input.split(Pattern.quote("☼"));
			userName = parsedInfo[0];
			password = parsedInfo[1];
			message = parsedInfo[2];
			if (message.equals(".bye")) {
				client.send("Disconnecting now ...");
				client.send(".bye");
				remove(ID);
			} else if (message.contains("fuck")) {
				client.send("Rude! Timeout!\nDisconnecting now ...");
				client.send(".bye");
				remove(ID);
			} else if (message.length() > 160) {
				client.send("Client " + ID + " - too prolix!!!\nDisconnecting now ...");
				client.send(".bye");
				remove(ID);
			} else {
				for (int i = 0; i < noOfClients; i++) {
					chatField.setText(chatField.getText() + "\n" + userName + ": " + message);
					clients[i].send(userName + ": " + message);
					System.out.println("Sending message");
				}
			}
		}

	}

	public void registerUser(String username, String password) {
		try (FileWriter fw = new FileWriter("user_pass.txt", true);
				BufferedWriter bw = new BufferedWriter(fw);
				PrintWriter out = new PrintWriter(bw)) {
			out.println(username + ":" + password);
		} catch (IOException e) {
			// File writing/opening failed at some stage.
		}
	}

	public boolean checkLogin(String username, String password) {
		boolean valid = false;

		ArrayList<String> lines = new ArrayList<String>();
		String line;
		try {
			BufferedReader reader = new BufferedReader(new FileReader("user_pass.txt"));
			while ((line = reader.readLine()) != null) {
				lines.add(line);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

		String[] users = new String[lines.size()];
		String[] pass = new String[lines.size()];

		for (int i = 0; i < lines.size(); i++) {
			String[] output = lines.get(i).split("\\:");
			users[i] = output[0];
			pass[i] = output[1];
		}

		for (int i = 0; i < lines.size(); i++) {
			System.out.println(users[i] + ":" + pass[i]);
			if (users[i].equals(username) && pass[i].equals(password)) {
				System.out.println("found a match");
				valid = true;
				break;
			}
		}

		return valid;
	}

	public synchronized void remove(int ID) {
		int pos = findClient(ID);
		if (pos >= 0) {
			ChatServerThread toTerminate = clients[pos];
			System.out.println("Removing client " + ID + " at " + pos);
			chatField.setText(chatField.getText() + "\nRemoving client " + ID + " at " + pos);
			if (pos < noOfClients - 1)
				for (int i = pos + 1; i < noOfClients; i++)
					clients[i - 1] = clients[i];
			noOfClients--;
			try {
				toTerminate.close();
			} catch (IOException ioe) {
				System.out.println("Error closing t: " + ioe);
			}
			toTerminate.stop();
		}
	}

	private void addThread(Socket socket) {
		if (noOfClients < clients.length) {
			System.out.println("Client accepted: " + socket);
			chatField.setText(chatField.getText() + "\nClient accepted: " + socket);
			clients[noOfClients] = new ChatServerThread(this, socket);
			try {
				clients[noOfClients].open();
				clients[noOfClients].start();
				noOfClients++;
			} catch (IOException ioe) {
				System.out.println("Error opening thread: " + ioe);
			}
		} else {
			chatField.setText(chatField.getText() + "\nClient refused: maximum " + clients.length + " reached.");
			System.out.println("Client refused: maximum " + clients.length + " reached.");
		}

	}

	public static void main(String args[]) {
		ChatServer serverSocket = null;
		if (args.length != 1)
			System.out.println("Usage: java ChatServer port");
		else {
			java.awt.EventQueue.invokeLater(new Runnable() {
				public void run() {
					ChatServer serverSocket = new ChatServer(Integer.parseInt(args[0]));
				}
			});
		}

}

}