/**
    *  MicroEmulator
    *  Copyright (C) 2006-2007 Bartek Teodorczyk <barteo@barteo.net>
    *  Copyright (C) 2006-2007 Vlad Skarzhevskyy
    *
    *  It is licensed under the following two licenses as alternatives:
    *    1. GNU Lesser General Public License (the "LGPL") version 2.1 or any newer version
    *    2. Apache License (the "AL") Version 2.0
    *
   *  You may not use this file except in compliance with at least one of
   *  the above two licenses.
   *
   *  You may obtain a copy of the LGPL at
   *      http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt
   *
   *  You may obtain a copy of the AL at
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the LGPL or the AL for the specific language governing permissions and
   *  limitations.
   *
   *  @version $Id: MIDletSystemProperties.java 1858 2008-12-12 09:54:52Z barteo $
   */
  package org.microemu.app.util;
  
  import java.security.AccessControlContext;
  import java.security.AccessController;
  import java.security.PrivilegedExceptionAction;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Set;
  import java.util.Vector;
  
  import org.microemu.device.Device;
  import org.microemu.log.Logger;
  
  /**
   * @author vlads
   * 
   * This class is called by MIDlet to access System Property. Call injection is
   * made by MIDlet ClassLoaded
   * 
   */
  public class MIDletSystemProperties {
  
  	/**
  	 * This may be a configuration option. But not for applet and Web Start.
  	 */
  	public static boolean applyToJavaSystemProperties = true;
  
  	/**
  	 * Permits null values.
  	 */
  	private static final Map props = new HashMap();
  	
  	private static final Map permissions = new HashMap();
  
  	private static Map systemPropertiesPreserve;
  
  	private static List systemPropertiesDevice;
  
  	private static boolean wanrOnce = true;
  
  	private static boolean initialized = false;
  
  	/* The context to be used when starting MicroEmulator */
  	private static AccessControlContext acc;
  
  	private static void initOnce() {
  		// Can't use static initializer because of applyToJavaSystemProperties
  		// in applet
  		if (initialized) {
  			return;
  		}
  		initialized = true;
  		// This are set in Config
  		// setProperty("microedition.configuration", "CLDC-1.1");
  		// setProperty("microedition.profiles", "MIDP-2.0");
  		setProperty("microedition.platform", "MicroEmulator");
  		setProperty("microedition.encoding", getSystemProperty("file.encoding"));
  	}
  
  	/**
  	 * Allow Access to system properties from MIDlet
  	 */
  	public static void initContext() {
  		acc = AccessController.getContext();
  	}
  
  	/**
  	 * Gets the system property indicated by the specified key. The only
  	 * function called by MIDlet
  	 * 
 	 * @param key
 	 *            the name of the system property
 	 * @return
 	 */
 	public static String getProperty(String key) {
 		initOnce();
 		if (props.containsKey(key)) {
 			return (String) props.get(key);
 		}
 		String v = getDynamicProperty(key);
 		if (v != null) {
 			return v;
 		}
 		try {
 			return getSystemProperty(key);
 		} catch (SecurityException e) {
 			return null;
 		}
 	}
 
 	public static String getSystemProperty(String key) {
 		try {
 			if (acc != null) {
 				return getSystemPropertySecure(key);
 			} else {
 				return System.getProperty(key);
 			}
 		} catch (SecurityException e) {
 			return null;
 		}
 	}
 
 	private static String getSystemPropertySecure(final String key) {
 		try {
 			return (String) AccessController.doPrivileged(new PrivilegedExceptionAction() {
 				public Object run() {
 					return System.getProperty(key);
 				}
 			}, acc);
 		} catch (Throwable e) {
 			return null;
 		}
 	}
 
 	private static String getDynamicProperty(String key) {
 		if (key.equals("microedition.locale")) {
 			return Locale.getDefault().getLanguage();
 		}
 		return null;
 	}
 
 	public static Set getPropertiesSet() {
 		initOnce();
 		return props.entrySet();
 	}
 
 	public static String setProperty(String key, String value) {
 		initOnce();
 		if (applyToJavaSystemProperties) {
 			try {
 				if (value == null) {
 					System.getProperties().remove(key);
 				} else {
 					System.setProperty(key, value);
 				}
 			} catch (SecurityException e) {
 				if (wanrOnce) {
 					wanrOnce = false;
 					Logger.error("Cannot update Java System.Properties", e);
 					Logger.debug("Continue ME2 operations with no updates to system Properties");
 				}
 			}
 		}
 		return (String) props.put(key, value);
 	}
 
 	public static String clearProperty(String key) {
 		if (applyToJavaSystemProperties) {
 			try {
 				System.getProperties().remove(key);
 			} catch (SecurityException e) {
 				if (wanrOnce) {
 					wanrOnce = false;
 					Logger.error("Cannot update Java System.Properties", e);
 				}
 			}
 		}
 		return (String) props.remove(key);
 	}
 
 	public static void setProperties(Map properties) {
 		initOnce();
 		for (Iterator i = properties.entrySet().iterator(); i.hasNext();) {
 			Map.Entry e = (Map.Entry) i.next();
 			setProperty((String) e.getKey(), (String) e.getValue());
 		}
 	}
 	
 	public static int getPermission(String permission) {
 		Integer value = (Integer) permissions.get(permission);
 		if (value == null) {
 			return -1;
 		} else {
 			return value.intValue();
 		}
 	}
 	
 	public static void setPermission(String permission, int value) {
 		permissions.put(permission, new Integer(value));
 	}
 
 	public static void setDevice(Device newDevice) {
 		initOnce();
 		// Restore System Properties from previous device activation.
 		if (systemPropertiesDevice != null) {
 			for (Iterator iter = systemPropertiesDevice.iterator(); iter.hasNext();) {
 				clearProperty((String) iter.next());
 			}
 		}
 		if (systemPropertiesPreserve != null) {
 			for (Iterator i = systemPropertiesPreserve.entrySet().iterator(); i.hasNext();) {
 				Map.Entry e = (Map.Entry) i.next();
 				setProperty((String) e.getKey(), (String) e.getValue());
 			}
 		}
 		systemPropertiesDevice = new Vector();
 		systemPropertiesPreserve = new HashMap();
 		for (Iterator i = newDevice.getSystemProperties().entrySet().iterator(); i.hasNext();) {
 			Map.Entry e = (Map.Entry) i.next();
 			String key = (String) e.getKey();
 			if (props.containsKey(key)) {
 				systemPropertiesPreserve.put(key, props.get(key));
 			} else {
 				systemPropertiesDevice.add(key);
 			}
 			setProperty(key, (String) e.getValue());
 		}
 	}
 }