/**
    *  BlueCove - Java library for Bluetooth
    *  Copyright (C) 2006-2008 Vlad Skarzhevskyy
    *
    *  Licensed to the Apache Software Foundation (ASF) under one
    *  or more contributor license agreements.  See the NOTICE file
    *  distributed with this work for additional information
    *  regarding copyright ownership.  The ASF licenses this file
    *  to you under the Apache License, Version 2.0 (the
   *  "License"); you may not use this file except in compliance
   *  with the License.  You may obtain a copy of the License 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 License for the
   *  specific language governing permissions and limitations
   *  under the License.
   *
   *  @author vlads
   *  @version $Id: NativeLibLoader.java 2476 2008-12-01 17:41:59Z skarzhevskyy $
   */
  package com.intel.bluetooth;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Hashtable;
  
  import com.ibm.oti.vm.VM;
  
  /**
   * Load native library from resources.
   *
   *
   * By default Native Library is extracted from from jar to temporary directory
   * `${java.io.tmpdir}/bluecove_${user.name}_N` and loaded from this location.
   * <p>
   * If you wish to load library (.dll) from another location add this system
   * property `-Dbluecove.native.path=/your/path`.
   * <p>
   * If you wish to load library from default location in path e.g.
   * `%SystemRoot%\system32` or any other location in %PATH% use
   * `-Dbluecove.native.resource=false`
   *
   */
  public abstract class NativeLibLoader {
  
  	static final int OS_UNSUPPORTED = -1;
  
  	static final int OS_LINUX = 1;
  
  	static final int OS_WINDOWS = 2;
  
  	static final int OS_WINDOWS_CE = 3;
  
  	static final int OS_MAC_OS_X = 4;
  
  	private static int os = 0;
  
  	private static Hashtable libsState = new Hashtable();
  
  	private static String bluecoveDllDir = null;
  
  	private static class LibState {
  
  		boolean triedToLoadAlredy = false;
  
  		boolean libraryAvailable = false;
  
  	}
  
  	private NativeLibLoader() {
  
  	}
  
  	static int getOS() {
  		if (os != 0) {
  			return os;
  		}
  		String sysName = System.getProperty("os.name");
  		if (sysName == null) {
  			DebugLog.fatal("Native Library not available on unknown platform");
  			os = OS_UNSUPPORTED;
  		} else {
  			sysName = sysName.toLowerCase();
  			if (sysName.indexOf("windows") != -1) {
  				if (sysName.indexOf("ce") != -1) {
  					os = OS_WINDOWS_CE;
  				} else {
  					os = OS_WINDOWS;
  				}
  			} else if (sysName.indexOf("mac os x") != -1) {
  				os = OS_MAC_OS_X;
  			} else if (sysName.indexOf("linux") != -1) {
  				os = OS_LINUX;
 			} else {
 				DebugLog.fatal("Native Library not available on platform " + sysName);
 				os = OS_UNSUPPORTED;
 			}
 		}
 		return os;
 	}
 
 	static boolean isAvailable(String name) {
 		return isAvailable(name, null);
 	}
 
 	static boolean isAvailable(String name, Class stackClass) {
 		LibState state = (LibState) libsState.get(name);
 		if (state == null) {
 			state = new LibState();
 			libsState.put(name, state);
 		}
 		if (state.triedToLoadAlredy) {
 			return state.libraryAvailable;
 		}
 		String libName = name;
 		String libFileName = libName;
 
 		// DebugLog.debug("OS:" + System.getProperty("os.name") + "|" +
 		// System.getProperty("os.version") + "|" +
 		// System.getProperty("os.arch"));
 		// DebugLog.debug("Java:" + System.getProperty("java.vendor") + " " +
 		// System.getProperty("java.version"));
 
 		String sysName = System.getProperty("os.name");
 
 		String sysArch = System.getProperty("os.arch");
 		if (sysArch != null) {
 			sysArch = sysArch.toLowerCase();
 		} else {
 			sysArch = "";
 		}
 
 		switch (getOS()) {
 		case OS_UNSUPPORTED:
 			DebugLog.fatal("Native Library " + name + " not available on [" + sysName + "] platform");
 			state.triedToLoadAlredy = true;
 			state.libraryAvailable = false;
 			return state.libraryAvailable;
 		case OS_WINDOWS_CE:
 			libName += "_ce";
 			libFileName = libName;
 			libFileName = libFileName + ".dll";
 			break;
 		case OS_WINDOWS:
 			if ((sysArch.indexOf("amd64") != -1) || (sysArch.indexOf("x86_64") != -1)) {
 				libName += "_x64";
 				libFileName = libName;
 			}
 			libFileName = libFileName + ".dll";
 			break;
 		case OS_MAC_OS_X:
 			libFileName = "lib" + libFileName + ".jnilib";
 			break;
 		case OS_LINUX:
 			if ((sysArch.indexOf("i386") != -1) || (sysArch.length() == 0)) {
 				// regular Intel
 			} else if ((sysArch.indexOf("amd64") != -1) || (sysArch.indexOf("x86_64") != -1)) {
 				libName += "_x64";
 			} else if ((sysArch.indexOf("x86") != -1)) {
 				// regular Intel under IBM J9
 			} else {
 				// Any other system
 				libName += "_" + sysArch;
 			}
 			libFileName = libName;
 			libFileName = "lib" + libFileName + ".so";
 			break;
 		default:
 			DebugLog.fatal("Native Library " + name + " not available on platform " + sysName);
 			state.triedToLoadAlredy = true;
 			state.libraryAvailable = false;
 			return state.libraryAvailable;
 		}
 
 		String path = System.getProperty(BlueCoveConfigProperties.PROPERTY_NATIVE_PATH);
 		if (path != null) {
 			if (!UtilsJavaSE.ibmJ9midp) {
 				state.libraryAvailable = tryloadPath(path, libFileName);
 			} else {
 				// Not working
 				// state.libraryAvailable = tryloadPathIBMj9MIDP(path,
 				// libFileName);
 			}
 		}
 		boolean useResource = true;
 		String d = System.getProperty(BlueCoveConfigProperties.PROPERTY_NATIVE_RESOURCE);
 		if ((d != null) && (d.equalsIgnoreCase("false"))) {
 			useResource = false;
 		}
 
 		if ((!state.libraryAvailable) && (useResource) && (!UtilsJavaSE.ibmJ9midp)) {
 			state.libraryAvailable = loadAsSystemResource(libFileName, stackClass);
 		}
 		if (!state.libraryAvailable) {
 			if (!UtilsJavaSE.ibmJ9midp) {
 				state.libraryAvailable = tryload(libName);
 			} else {
 				state.libraryAvailable = tryloadIBMj9MIDP(libName);
 			}
 		}
 
 		if (!state.libraryAvailable) {
 			System.err.println("Native Library " + libName + " not available");
 			DebugLog.debug("java.library.path", System.getProperty("java.library.path"));
 		}
 		state.triedToLoadAlredy = true;
 		return state.libraryAvailable;
 	}
 
 	private static boolean tryload(String name) {
 		try {
 			System.loadLibrary(name);
 			DebugLog.debug("Library loaded", name);
 		} catch (Throwable e) {
 			DebugLog.error("Library " + name + " not loaded ", e);
 			return false;
 		}
 		return true;
 	}
 
 	private static boolean tryloadIBMj9MIDP(String name) {
 		try {
 			VM.loadLibrary(name);
 			DebugLog.debug("Library loaded", name);
 		} catch (Throwable e) {
 			DebugLog.error("Library " + name + " not loaded ", e);
 			return false;
 		}
 		return true;
 	}
 
 	private static boolean tryloadPath(String path, String name) {
 		try {
 			File f = new File(path, name);
 			if (!f.canRead()) {
 				DebugLog.fatal("Native Library " + f.getAbsolutePath() + " not found");
 				return false;
 			}
 			System.load(f.getAbsolutePath());
 			DebugLog.debug("Library loaded", f.getAbsolutePath());
 		} catch (Throwable e) {
 			DebugLog.error("Can't load library from path " + path, e);
 			return false;
 		}
 		return true;
 	}
 
 	private static boolean tryloadPathIBMj9MIDP(String path, String name) {
 		try {
 			VM.loadLibrary(path + "\\" + name);
 			DebugLog.debug("Library loaded", path + "\\" + name);
 		} catch (Throwable e) {
 			DebugLog.error("Can't load library from path " + path + "\\" + name, e);
 			return false;
 		}
 		return true;
 	}
 
 	private static boolean loadAsSystemResource(String libFileName, Class stackClass) {
 		InputStream is = null;
 		try {
 			ClassLoader clo = null;
 			try {
 				if (stackClass != null) {
 					clo = stackClass.getClassLoader();
 					DebugLog.debug("Use stack ClassLoader");
 				} else {
 					clo = NativeLibLoader.class.getClassLoader();
 				}
 			} catch (Throwable j9) {
 			}
 			if (clo == null) {
 				DebugLog.debug("Use System ClassLoader");
 				is = ClassLoader.getSystemResourceAsStream(libFileName);
 			} else {
 				is = clo.getResourceAsStream(libFileName);
 			}
 		} catch (Throwable e) {
 			DebugLog.error("Native Library " + libFileName + " is not a Resource !");
 			return false;
 		}
 		if (is == null) {
 			DebugLog.error("Native Library " + libFileName + " is not a Resource !");
 			return false;
 		}
 		File fd = makeTempName(libFileName);
 		try {
 			if (!copy2File(is, fd)) {
 				return false;
 			}
 		} finally {
 			try {
 				is.close();
 			} catch (IOException ignore) {
 				is = null;
 			}
 		}
 		try {
 			fd.deleteOnExit();
 		} catch (Throwable e) {
 			// Java 1.1 or J9
 		}
 		// deleteOnExit(fd);
 		try {
 			System.load(fd.getAbsolutePath());
 			DebugLog.debug("Library loaded from", fd);
 		} catch (Throwable e) {
 			DebugLog.error("Can't load library file ", e);
 			return false;
 		}
 		return true;
 	}
 
 	private static boolean copy2File(InputStream is, File fd) {
 		FileOutputStream fos = null;
 		try {
 			fos = new FileOutputStream(fd);
 			byte b[] = new byte[1000];
 			int len;
 			while ((len = is.read(b)) >= 0) {
 				fos.write(b, 0, len);
 			}
 			return true;
 		} catch (Throwable e) {
 			DebugLog.debug("Can't create temporary file ", e);
 			System.err.println("Can't create temporary file " + fd.getAbsolutePath());
 			return false;
 		} finally {
 			if (fos != null) {
 				try {
 					fos.close();
 				} catch (IOException ignore) {
 					fos = null;
 				}
 			}
 		}
 	}
 
 	private static File makeTempName(String libFileName) {
 		if (bluecoveDllDir != null) {
 			return new File(bluecoveDllDir, libFileName);
 		}
 		String tmpDir = System.getProperty("java.io.tmpdir");
 		String uname = System.getProperty("user.name");
 		int count = 0;
 		File fd = null;
 		File dir = null;
 		selectDirectory: while (true) {
 			if (count > 10) {
 				DebugLog.debug("Can't create temporary dir " + dir.getAbsolutePath());
 				return new File(tmpDir, libFileName);
 			}
 			dir = new File(tmpDir, "bluecove_" + uname + "_" + (count++));
 			if (dir.exists()) {
 				if (!dir.isDirectory()) {
 					continue selectDirectory;
 				}
 				// Remove all files.
 				try {
 					File[] files = dir.listFiles();
 					for (int i = 0; i < files.length; i++) {
 						if (!files[i].delete()) {
 							continue selectDirectory;
 						}
 					}
 				} catch (Throwable e) {
 					// Java 1.1 or J9
 				}
 			}
 			if ((!dir.exists()) && (!dir.mkdirs())) {
 				DebugLog.debug("Can't create temporary dir ", dir.getAbsolutePath());
 				continue selectDirectory;
 			}
 			try {
 				dir.deleteOnExit();
 			} catch (Throwable e) {
 				// Java 1.1 or J9
 			}
 			fd = new File(dir, libFileName);
 			if ((fd.exists()) && (!fd.delete())) {
 				continue;
 			}
 			try {
 				if (!fd.createNewFile()) {
 					DebugLog.debug("Can't create file in temporary dir ", fd.getAbsolutePath());
 					continue;
 				}
 			} catch (IOException e) {
 				DebugLog.debug("Can't create file in temporary dir ", fd.getAbsolutePath());
 				continue;
 			} catch (Throwable e) {
 				// Java 1.1 or J9
 			}
 			bluecoveDllDir = dir.getAbsolutePath();
 			break;
 		}
 		return fd;
 	}
 
 	// private static void deleteOnExit(final File fd) {
 	// Runnable r = new Runnable() {
 	// public void run() {
 	// if (!fd.delete()) {
 	// System.err.println("Can't remove Native Library " + fd);
 	// }
 	// }
 	// };
 	// Runtime.getRuntime().addShutdownHook(new Thread(r));
 	// }
 
 }