package mixconfig.tools.dataretention.smartcard;

import java.util.List;

import javax.smartcardio.ATR;
import javax.smartcardio.Card;
import javax.smartcardio.CardChannel;
import javax.smartcardio.CardException;
import javax.smartcardio.CardTerminal;
import javax.smartcardio.CommandAPDU;
import javax.smartcardio.ResponseAPDU;
import javax.smartcardio.TerminalFactory;

import mixconfig.tools.dataretention.smartcard.commands.AbstractCommand;
import mixconfig.tools.dataretention.smartcard.commands.ErrorCodeException;
import mixconfig.tools.dataretention.smartcard.commands.SelectAnonCardAppletCommand;


public class ConnectionManager {
	private static ConnectionManager instance;
	private CardChannel channel;

	/**
	 * Cached version of the SmartCardProxy
	 */
	private ISmartCard smartCard;

	private ConnectionManager() {
		// Empty constructor for singleton
	}

	public static ConnectionManager getInstance() {
		if (instance == null) {
			instance = new ConnectionManager();
		}
		return instance;
	}

	public ISmartCard connect() {
		if (smartCard == null) {
			/*
			 * Socket sock; sock = new Socket("localhost", 9025); InputStream is
			 * = sock.getInputStream(); OutputStream os =
			 * sock.getOutputStream();
			 * 
			 * channel = CadDevice.getCadClientInstance(CadDevice.PROTOCOL_T1,
			 * is, os); channel.powerUp(); if (useEmulator) {
			 * installAnonApplet(); }
			 */

			if (connectToSmartCard()) {
				smartCard = new SmartCardProxy(this);
			}
		}
		return smartCard;
	}

	private void selectAnonApplet() throws ErrorCodeException {
		AbstractCommand command = new SelectAnonCardAppletCommand();
		processCommand(command);

	}

	public void disconnect() {
		/*
		 * try { channel.powerDown(); } catch (IOException e) { // TODO
		 * Auto-generated catch block e.printStackTrace(); } catch
		 * (CadTransportException e) { // TODO Auto-generated catch block
		 * e.printStackTrace(); }
		 */
	}

	void processCommand(AbstractCommand command) throws ErrorCodeException {
		CommandAPDU commandApdu = command.buildCommandApdu();
		ResponseAPDU responseApdu;
		try {
			responseApdu = channel.transmit(commandApdu);
			command.setResponse(responseApdu.getData(), responseApdu.getSW1(), responseApdu.getSW2());
		} catch (CardException e) {
			e.printStackTrace();
		}

	}

	/**
	 * Method returns list of smart card readers available in system
	 * 
	 * @returns readersList
	 * 
	 */
	private List<CardTerminal> getReaderList() {
		try {
			TerminalFactory factory = TerminalFactory.getDefault();
			List<CardTerminal> readersList = factory.terminals().list();
			return readersList;
		} catch (Exception ex) {
			System.out.println("Exception : " + ex);
			return null;
		}
	}

	public boolean connectToSmartCard() {
		// TRY ALL READERS, FIND FIRST SELECTABLE
		List<CardTerminal> terminalList = getReaderList();

		// List numbers of Card readers
		for (int i = 0; i < terminalList.size(); i++) {
			System.out.println(i + " : " + terminalList.get(i));
			CardTerminal m_terminal = terminalList.get(i);
			try {
				if (m_terminal.isCardPresent()) {
					// TRY TO CONNECT VIA T0 AND IF FAIL THEN BY T1
					// Card m_card = m_terminal.connect("T=0");
					Card m_card = m_terminal.connect("*");

					System.out.println("card: " + m_card);
					channel = m_card.getBasicChannel();

					// reset the card
					ATR atr = m_card.getATR();
					System.out.println(atr.toString());

					// SELECT APPLET
					try {
						selectAnonApplet();
						return true;
					} catch (ErrorCodeException e) {
						System.out.println("Card without ANONCardApplet found.");
					}
				}
			} catch (CardException e) {
				System.out.println("Cannot communicate with Card.");
			}
		}
		channel = null;
		return false;
	}
}