/*
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details ( see the LICENSE file ).
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.gudy.azureus2.platform.unix;

import java.io.*;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.gudy.azureus2.core3.config.COConfigurationManager;
import org.gudy.azureus2.core3.util.Constants;
import org.gudy.azureus2.core3.util.Debug;
import org.gudy.azureus2.core3.util.FileUtil;

import com.aelitis.azureus.core.impl.AzureusCoreSingleInstanceClient;

import org.gudy.azureus2.plugins.PluginManager;

public class ScriptBeforeStartup
{
	private static PrintStream sysout;

	private static Object display;

	public static void main(String[] args) {
		// Set transitory so not everything gets loaded up. (such as the AEDiagnostic's tidy flag)
		System.setProperty("transitory.startup", "1");

		// Since stdout will be in a shell script, redirect any stdout not coming
		// from us to stderr 
		sysout = System.out;
		try {
			System.setOut(new PrintStream(new FileOutputStream("/dev/stderr")));
		} catch (FileNotFoundException e) {
		}

  	String mi_str = System.getProperty(PluginManager.PR_MULTI_INSTANCE);
		boolean mi = mi_str != null && mi_str.equalsIgnoreCase("true");

		if (!mi) {
  		boolean argsSent = new AzureusCoreSingleInstanceClient().sendArgs(args, 500);
  		if (argsSent) {
  			// azureus was open..
  			String msg = "Passing startup args to already-running " + Constants.APP_NAME + " java process listening on [127.0.0.1: " + Constants.INSTANCE_PORT + "]";
  			log(msg);
  			sysout.println("exit");
  
  			return;
  		}
		}

		// If the after shutdown script didn't run or crapped out, then
		// don't run again..
		String scriptAfterShutdown = COConfigurationManager.getStringParameter(
				"scriptaftershutdown", null);

		COConfigurationManager.removeParameter("scriptaftershutdown.exit");
		COConfigurationManager.removeParameter("scriptaftershutdown");
		COConfigurationManager.save();
		if (scriptAfterShutdown != null) {
			log("Script after " + Constants.APP_NAME + " shutdown did not run.. running now");

			sysout.println(scriptAfterShutdown);

			if (scriptAfterShutdown.indexOf("$0") < 0) {
				// doesn't have a restart.. add one
				sysout.println("echo \"Restarting Azureus..\"");
				sysout.println("$0\n");
			}
			// exit is a requirement
			sysout.println("exit");

			return;
		}

		String moz = getNewGreDir();

		if (moz != null) {
			String s = "export MOZILLA_FIVE_HOME=\"" + moz + "\"\n"
					+ "if [ \"$LD_LIBRARY_PATH x\" = \" x\" ] ; then\n"
					+ "	export LD_LIBRARY_PATH=$MOZILLA_FIVE_HOME;\n" + "else\n"
					+ "	export LD_LIBRARY_PATH=$MOZILLA_FIVE_HOME:$LD_LIBRARY_PATH\n"
					+ "fi\n";
			sysout.println(s);
			log("setting LD_LIBRARY_PATH to: $LD_LIBRARY_PATH");
			log("setting MOZILLA_FIVE_HOME to: $MOZILLA_FIVE_HOME");
		} else {
			log("GRE/XULRunner automatically found");
		}
	}

	public static String getNewGreDir() {
		// SWT does a pretty awesome job at finding GRE, most cases this will work
		if (canOpenBrowser()) {
			return null;
		}

		// TODO: Store last successful dir somewhere and check that first
		//       COConfigurationManager probably a bad idea, since that may load
		//       Logger and who knows what other libraries
		String grePath = null;
		final String[] confList = {
			"/etc/gre64.conf",
			"/etc/gre.d/gre64.conf",
			"/etc/gre.conf",
			"/etc/gre.d/gre.conf",
			"/etc/gre.d/xulrunner.conf",
			"/etc/gre.d/libxul0d.conf"
		};

		log("Auto-scanning for GRE/XULRunner.  You can skip this by appending the GRE path to LD_LIBRARY_PATH and setting MOZILLA_FIVE_HOME.");
		try {
			Pattern pat = Pattern.compile("GRE_PATH=(.*)", Pattern.CASE_INSENSITIVE);
			for (int i = 0; i < confList.length; i++) {
				File file = new File(confList[i]);
				if (file.isFile() && file.canRead()) {
					log("  checking " + file + " for GRE_PATH");
					String fileText = FileUtil.readFileAsString(file, 16384);
					if (fileText != null) {
						Matcher matcher = pat.matcher(fileText);
						if (matcher.find()) {
							String possibleGrePath = matcher.group(1);
							if (isValidGrePath(new File(possibleGrePath))) {
								grePath = possibleGrePath;
								break;
							}
						}
					}
				}
			}

			if (grePath == null) {
				final ArrayList possibleDirs = new ArrayList();
				File libDir = new File("/usr");
				libDir.listFiles(new FileFilter() {
					public boolean accept(File pathname) {
						if (pathname.getName().startsWith("lib")) {
							possibleDirs.add(pathname);
						}
						return false;
					}
				});
				possibleDirs.add(new File("/usr/local"));
				possibleDirs.add(new File("/opt"));

				final String[] possibleDirNames = {
					"mozilla",
					"firefox",
					"seamonkey",
					"xulrunner",
				};

				FileFilter ffIsPossibleDir = new FileFilter() {
					public boolean accept(File pathname) {
						String name = pathname.getName().toLowerCase();
						for (int i = 0; i < possibleDirNames.length; i++) {
							if (name.startsWith(possibleDirNames[i])) {
								return true;
							}
						}
						return false;
					}
				};

				for (Iterator iter = possibleDirs.iterator(); iter.hasNext();) {
					File dir = (File) iter.next();

					File[] possibleFullDirs = dir.listFiles(ffIsPossibleDir);

					for (int i = 0; i < possibleFullDirs.length; i++) {
						log("  checking " + possibleFullDirs[i] + " for GRE");
						if (isValidGrePath(possibleFullDirs[i])) {
							grePath = possibleFullDirs[i].getAbsolutePath();
							break;
						}
					}
					if (grePath != null) {
						break;
					}
				}
			}

			if (grePath != null) {
				log("GRE found at " + grePath + ".");
				System.setProperty("org.eclipse.swt.browser.XULRunnerPath", grePath);
			}
		} catch (Throwable t) {
			log("Error trying to find suitable GRE: "
					+ Debug.getNestedExceptionMessage(t));
			grePath = null;
		}

		if (!canOpenBrowser()) {
			log("Can't create browser.  Will try to set LD_LIBRARY_PATH and hope "
					+ Constants.APP_NAME + " has better luck.");
		}

		return grePath;
	}

	private static boolean canOpenBrowser() {
		try {
			Class claDisplay = Class.forName("org.eclipse.swt.widgets.Display");
			if (display != null) {
				display = claDisplay.newInstance();
			}
			Class claShell = Class.forName("org.eclipse.swt.widgets.Shell");
			Constructor shellConstruct = claShell.getConstructor(new Class[] {
				claDisplay,
			});
			Object shell = shellConstruct.newInstance(new Object[] {
				display
			});

			Class claBrowser = Class.forName("org.eclipse.swt.browser.Browser");
			Constructor[] constructors = claBrowser.getConstructors();
			for (int i = 0; i < constructors.length; i++) {
				if (constructors[i].getParameterTypes().length == 2) {
					Object browser = constructors[i].newInstance(new Object[] {
						shell,
						new Integer(0)
					});

					Method methSetUrl = claBrowser.getMethod("setUrl", new Class[] {
						String.class
					});
					methSetUrl.invoke(browser, new Object[] {
						"about:blank"
					});

					break;
				}
			}
			Method methDisposeShell = claShell.getMethod("dispose", new Class[] {});
			methDisposeShell.invoke(shell, new Object[] {});

			return true;
		} catch (Throwable e) {
			log("Browser check failed with: " + Debug.getNestedExceptionMessage(e));
			return false;
		}

	}

	private static boolean isValidGrePath(File dir) {
		if (!dir.isDirectory()) {
			return false;
		}
		
		if (new File(dir, "components/libwidget_gtk.so").exists()
				|| new File(dir, "libwidget_gtk.so").exists()) {
			log("	Can not use GRE from " + dir
					+ " as it's too old (GTK2 version required).");
			return false;
		}

		// newer GRE doesn't have libwidget at all, but older ones do, and it's 
		// gtk2, we are good to go
		if (new File(dir, "components/libwidget_gtk2.so").exists()
				|| new File(dir, "libwidget_gtk2.so").exists()) {
			return true;
		}

		if (!new File(dir, "components/libxpcom.so").exists()
				&& !new File(dir, "libxpcom.so").exists()) {
			log("	Can not use GRE from " + dir + " because it's missing libxpcom.so.");
			return false;
		}

		return true;
	}

	private static void log(String string) {
		sysout.println("echo \"" + string.replaceAll("\"", "\\\"") + "\"");
	}
}
