/****************************************************************************
 * 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.scio.osx;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.AccessController;
import java.security.PrivilegedAction;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * OS X specific PlatformPCSC. For more information see {@link package-info}.
 * 
 * @author Benedikt Biallowons <benedikt.biallowons@ecsec.de>
 */
public class PlatformPCSC {

  private static final String PCSC_JNI_LIBRARY_PATH = "/at/gv/egiz/smcc/osx-pcsc-jni/";
  private static final String PCSC_JNI_LIBRARY_NAME = "libosxj2pcsc.dylib";
  private static final String PCSC_FRAMEWORK = "/System/Library/Frameworks/PCSC.framework/Versions/Current/PCSC";

  private final static Logger log = LoggerFactory.getLogger(PlatformPCSC.class);

  public static final int SCARD_PROTOCOL_T0 = 0x0001;
  public static final int SCARD_PROTOCOL_T1 = 0x0002;
  public static final int SCARD_PROTOCOL_RAW = 0x0004;
  public static final int SCARD_UNKNOWN = 0x0001;
  public static final int SCARD_ABSENT = 0x0002;
  public static final int SCARD_PRESENT = 0x0004;
  public static final int SCARD_SWALLOWED = 0x0008;
  public static final int SCARD_POWERED = 0x0010;
  public static final int SCARD_NEGOTIABLE = 0x0020;
  public static final int SCARD_SPECIFIC = 0x0040;

  public static final Exception INIT_EXCEPTION;

  static {
    INIT_EXCEPTION = AccessController
        .doPrivileged(new PrivilegedAction<Exception>() {
          public Exception run() {
            try {
              String[] parts = PCSC_JNI_LIBRARY_NAME.split("\\.");

              File tempFile = File.createTempFile(parts[0], parts[1]);
              tempFile.deleteOnExit();

              log.debug("Copying " + PCSC_JNI_LIBRARY_PATH + getLibrary() + " to " + tempFile);
              InputStream is = PlatformPCSC.class
                  .getResourceAsStream(PCSC_JNI_LIBRARY_PATH + getLibrary());

              if (is == null) {
                return new FileNotFoundException(getLibrary() + " not found.");
              }

              OutputStream os = new FileOutputStream(tempFile);

              try {
                byte[] buffer = new byte[1024];
                int readBytes;

                while ((readBytes = is.read(buffer)) != -1) {
                  os.write(buffer, 0, readBytes);
                }

                log.debug("loading " + tempFile.getAbsolutePath());
                System.load(tempFile.getAbsolutePath());
                initialize(PCSC_FRAMEWORK);
              } finally {
                os.close();
                is.close();
              }

              return null;
            } catch (Exception e) {
              return e;
            }
          }
        });
  }

  /**
   * Chooses a suitable JNI library depending the current JRE.
   * 
   * @return library filename
   */
  private static String getLibrary() {
    String javaVersion = System.getProperty("java.version");

    if (javaVersion.startsWith("1.6")) {
      return "jre6." + PCSC_JNI_LIBRARY_NAME;
    } else if (javaVersion.startsWith("1.7")) {
      return "jre7." + PCSC_JNI_LIBRARY_NAME;
    }

    return null;
  }

  private static native void initialize(String libraryName);

}