/****************************************************************************
 * Copyright (C) 2012-2013 ecsec GmbH.
 * All rights reserved.
 * Contact: ecsec GmbH (info@ecsec.de)
 *
 * This file is part of the Open eCard App.
 *
 * GNU General Public License Usage
 * This file may be used under the terms of the GNU General Public
 * License version 3.0 as published by the Free Software Foundation
 * and appearing in the file LICENSE.GPL included in the packaging of
 * this file. Please review the following information to ensure the
 * GNU General Public License version 3.0 requirements will be met:
 * http://www.gnu.org/copyleft/gpl.html.
 *
 * Other Usage
 * Alternatively, this file may be used in accordance with the terms
 * and conditions contained in a signed written agreement between
 * you and ecsec GmbH.
 *
 ***************************************************************************/

package org.openecard.control.module.tctoken;

import java.io.IOException;
import java.net.URL;
import org.openecard.common.util.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * Helper class to fixObjectTag common problems with TCTokens.
 * TCToken provider may handle the TCToken generation in sloppy way. According to the specification, it is up to the
 * client to be as forgiving as possible. This class has fixes for the problems we have seen in the past.
 *
 * @author Moritz Horsch <horsch@cdc.informatik.tu-darmstadt.de>
 * @author Tobias Wich <tobias.wich@ecsec.de>
 * @author Dirk Petrautzki <petrautzki@hs-coburg.de>
 */
public class TCTokenHacks {

    private static final Logger logger = LoggerFactory.getLogger(TCTokenHacks.class);

    /**
     * Fixes PathSecurity-Parameters if the trailing s is missing.
     *
     * @param input Possibly errornous string containing the token.
     * @return Fixed data.
     */
    public static String fixPathSecurityParaneters(String input) {
	if (! input.contains("PathSecurity-Parameters")) {
	    input = input.replace("PathSecurity-Parameter", "PathSecurity-Parameters");
	}
	if (input.contains("<PSK>")) {
	    input = input.replace("<PSK>", "<PSK>");
	}
	if (input.contains("</PSK>")) {
	    input = input.replace("</PSK>", "</PSK>");
	}
	return input;
    }

    /**
     * Converts an Object tag to a TCToken, if applicable.
     * If the parameter contains an object element it is converted to a TCTpkenType. If it is already a TCTokenType, the
     * string is returned as is.
     * .
     * @param input Possibly errornous string containing the token.
     * @return Fixed data
     */
    public static String fixObjectTag(String input) {
	int x = input.indexOf("<object");
	int y = input.indexOf("object", x + 7);

	// there is nothing to do here ... leave
	if (x == -1 || y == -1) {
	    return input;
	}

	String data = input.substring(x, y);

	StringBuilder out = new StringBuilder(2048);
	out.append("<TCTokenType>");
	try {
	    while (true) {
		Pair<String, String> result = convertParameter(data);
		out.append(result.p1);
		data = result.p2;
	    }
	} catch (Exception ignore) {
	}
	out.append("</TCTokenType>");

	return out.toString();
    }

    private static Pair<String, String> convertParameter(String data) throws IOException {
	String input = data;
	StringBuilder out = new StringBuilder(2048);

	int x = input.indexOf("<param name=");
	if (x == -1) {
	    throw new IOException();
	} else {
	    x += 13;
	}
	String element = input.substring(x, input.indexOf("\"", x));

	int y = input.indexOf("value=", x) + 7;
	String value = input.substring(y, input.indexOf("\"", y));

	out.append("<").append(element).append(">");
	out.append(value);
	out.append("</").append(element).append(">");

	data = input.substring(y + value.length(), input.length());

	return new Pair<String, String>(out.toString(), data);
    }

    /**
     * Checks if checks according to BSI TR03112-7 3.4.2, 3.4.4 and 3.4.5 must be performed.
     *
     * @param tcTokenRequest TC Token request.
     * @return {@code true} if checks should be performed, {@code false} otherwise.
     */
    public static boolean isPerformTR03112Checks(TCTokenRequest tcTokenRequest) {
	boolean activationChecks = true;
	String refreshAddress = tcTokenRequest.getTCToken().getRefreshAddress().toString();
	URL tokenUrl = tcTokenRequest.getTCTokenURL();
	// disable checks when not using the nPA
	if (! tcTokenRequest.getCardType().equals("http://bsi.bund.de/cif/npa.xml")) {
	    activationChecks = false;
	// disable checks when using test servers with wrong certificates
	} else if (refreshAddress.startsWith("https://eservice.openecard.org")) {
	    activationChecks = false;
	} else if (tokenUrl != null) {
	    String tokenUrlStr = tokenUrl.toString();
	    if (tokenUrlStr.startsWith("https://mtg.as.skidentity.de")) {
		activationChecks = false;
	    }
	}
	return activationChecks;
    }

}