/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999, 2000 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.tools.ant;

import java.io.*;
import java.util.*;

/**
 * Command line entry point into Ant. This class is entered via the
 * cannonical `public static void main` entry point and reads the
 * command line arguments. It then assembles and executes an Ant
 * project.
 * <p>
 * If you integrating Ant into some other tool, this is not the class
 * to use as an entry point. Please see the source code of this
 * class to see how it manipulates the Ant project classes.
 *
 * @author duncan@x180.com
 */

public class Main {

    /** The default build file name */
    public static final String DEFAULT_BUILD_FILENAME = "build.xml";

    /** Our current message output status. Follows Project.MSG_XXX */
    private int msgOutputLevel = Project.MSG_INFO;

    /** File that we are using for configuration */
    private File buildFile; /** null */

    /** Stream that we are using for logging */
    private PrintStream out = System.out;

    /** Stream that we are using for logging error messages */
    private PrintStream err = System.err;

    /** The build targets */
    private Vector targets = new Vector(5);

    /** Set of properties that can be used by tasks */
    private Properties definedProps = new Properties();

    /** Names of classes to add as listeners to project */
    private Vector listeners = new Vector(5);

    /**
     * The Ant logger class. There may be only one logger. It will have the
     * right to use the 'out' PrintStream. The class must implements the BuildLogger
     * interface
     */
    private String loggerClassname = null;

    /**
     * Indicates whether output to the log is to be unadorned.
     */
    private boolean emacsMode = false;

    /**
     * Indicates if this ant should be run.
     */
    private boolean readyToRun = false;

    /**
     * Indicates we should only parse and display the project help information
     */
    private boolean projectHelp = false;

    /**
     * Prints the message of the Throwable if it's not null.
     */
    private static void printMessage(Throwable t) {
        String message = t.getMessage();
        if (message != null) {
            System.err.println(message);
        }
    }

    /**
     * Command line entry point. This method kicks off the building
     * of a project object and executes a build using either a given
     * target or the default target.
     *
     * @param args Command line args.
     */
    public static void main(String[] args) {
        Main m = null;

        try {
            m = new Main(args);
        } catch(Throwable exc) {
            printMessage(exc);
            System.exit(1);
        }

        try {
            m.runBuild();
            System.exit(0);
        } catch (BuildException be) {
            if (m.err != System.err) {
                printMessage(be);
            }
            System.exit(1);
        } catch(Throwable exc) {
            printMessage(exc);
            System.exit(1);
        }
    }

    protected Main(String[] args) throws BuildException {

        String searchForThis = null;

        // cycle through given args

        for (int i = 0; i < args.length; i++) {
            String arg = args[i];

            if (arg.equals("-help")) {
                printUsage();
                return;
            } else if (arg.equals("-version")) {
                printVersion();
                return;
            } else if (arg.equals("-quiet") || arg.equals("-q")) {
                msgOutputLevel = Project.MSG_WARN;
            } else if (arg.equals("-verbose") || arg.equals("-v")) {
                printVersion();
                msgOutputLevel = Project.MSG_VERBOSE;
            } else if (arg.equals("-debug")) {
                printVersion();
                msgOutputLevel = Project.MSG_DEBUG;
            } else if (arg.equals("-logfile") || arg.equals("-l")) {
                try {
                    File logFile = new File(args[i+1]);
                    i++;
                    out = new PrintStream(new FileOutputStream(logFile));
                    err = out;
                    System.setOut(out);
                    System.setErr(out);
                } catch (IOException ioe) {
                    String msg = "Cannot write on the specified log file. " +
                        "Make sure the path exists and you have write permissions.";
                    System.out.println(msg);
                    return;
                } catch (ArrayIndexOutOfBoundsException aioobe) {
                    String msg = "You must specify a log file when " +
                        "using the -log argument";
                    System.out.println(msg);
                    return;
                }
            } else if (arg.equals("-buildfile") || arg.equals("-file") || arg.equals("-f")) {
                try {
                    buildFile = new File(args[i+1]);
                    i++;
                } catch (ArrayIndexOutOfBoundsException aioobe) {
                    String msg = "You must specify a buildfile when " +
                        "using the -buildfile argument";
                    System.out.println(msg);
                    return;
                }
            } else if (arg.equals("-listener")) {
                try {
                    listeners.addElement(args[i+1]);
                    i++;
                } catch (ArrayIndexOutOfBoundsException aioobe) {
                    String msg = "You must specify a classname when " +
                        "using the -listener argument";
                    System.out.println(msg);
                    return;
                }
            } else if (arg.startsWith("-D")) {

                /* Interestingly enough, we get to here when a user
                 * uses -Dname=value. However, in some cases, the JDK
                 * goes ahead * and parses this out to args
                 *   {"-Dname", "value"}
                 * so instead of parsing on "=", we just make the "-D"
                 * characters go away and skip one argument forward.
                 *
                 * I don't know how to predict when the JDK is going
                 * to help or not, so we simply look for the equals sign.
                 */

                String name = arg.substring(2, arg.length());
                String value = null;
                int posEq = name.indexOf("=");
                if (posEq > 0) {
                    value = name.substring(posEq+1);
                    name = name.substring(0, posEq);
                } else if (i < args.length-1)
                    value = args[++i];

                definedProps.put(name, value);
            } else if (arg.equals("-logger")) {
                if (loggerClassname != null) {
                    System.out.println("Only one logger class may be specified.");
                    return;
                }
                loggerClassname = args[++i];
            } else if (arg.equals("-emacs")) {
                emacsMode = true;
            } else if (arg.equals("-projecthelp")) {
                // set the flag to display the targets and quit
                projectHelp = true;
            } else if (arg.equals("-find")) {
                // eat up next arg if present, default to build.xml
                if (i < args.length-1) {
                    searchForThis = args[++i];
                } else {
                    searchForThis = DEFAULT_BUILD_FILENAME;
                }
            } else if (arg.startsWith("-")) {
                // we don't have any more args to recognize!
                String msg = "Unknown argument: " + arg;
                System.out.println(msg);
                printUsage();
                return;
            } else {
                // if it's no other arg, it may be the target
                targets.addElement(arg);
            }

        }

        // if buildFile was not specified on the command line,
        if (buildFile == null) {
            // but -find then search for it
            if (searchForThis != null) {
                buildFile = findBuildFile(".", searchForThis);
            } else {
                buildFile = new File(DEFAULT_BUILD_FILENAME);
            }
        }

        // make sure buildfile exists
        if (!buildFile.exists()) {
            System.out.println("Buildfile: " + buildFile + " does not exist!");
            throw new BuildException("Build failed");
        }

        // make sure it's not a directory (this falls into the ultra
        // paranoid lets check everything catagory

        if (buildFile.isDirectory()) {
            System.out.println("What? Buildfile: " + buildFile + " is a dir!");
            throw new BuildException("Build failed");
        }

        readyToRun = true;
    }

    /**
     * Helper to get the parent file for a given file.
     *
     * <P>Added to simulate File.getParentFile() from JDK 1.2.
     *
     * @param file   File
     * @return       Parent file or null if none
     */
    private File getParentFile(File file) {
        String filename = file.getAbsolutePath();
        file = new File(filename);
        filename = file.getParent();

        if (filename != null && msgOutputLevel >= Project.MSG_VERBOSE) {
            System.out.println("Searching in "+filename);
        }

        return (filename == null) ? null : new File(filename);
    }

    /**
     * Search parent directories for the build file.
     *
     * <P>Takes the given target as a suffix to append to each
     *    parent directory in seach of a build file.  Once the
     *    root of the file-system has been reached an exception
     *    is thrown.
     *
     * @param suffix    Suffix filename to look for in parents.
     * @return          A handle to the build file
     *
     * @exception BuildException    Failed to locate a build file
     */
    private File findBuildFile(String start, String suffix) throws BuildException {
        if (msgOutputLevel >= Project.MSG_INFO) {
            System.out.println("Searching for " + suffix + " ...");
        }

        File parent = new File(new File(start).getAbsolutePath());
        File file = new File(parent, suffix);
        
        // check if the target file exists in the current directory
        while (!file.exists()) {
            // change to parent directory
            parent = getParentFile(parent);
            
            // if parent is null, then we are at the root of the fs,
            // complain that we can't find the build file.
            if (parent == null) {
                throw new BuildException("Could not locate a build file!");
            }
            
            // refresh our file handle
            file = new File(parent, suffix);
        }
        
        return file;
    }

    /**
     * Executes the build.
     */
    private void runBuild() throws BuildException {

        if (!readyToRun) {
            return;
        }

        // track when we started

        if (msgOutputLevel >= Project.MSG_INFO) {
            System.out.println("Buildfile: " + buildFile);
        }

        Project project = new Project();

        Throwable error = null;

        try {
            addBuildListeners(project);
            project.fireBuildStarted();

            project.init();

            // set user-define properties
            Enumeration e = definedProps.keys();
            while (e.hasMoreElements()) {
                String arg = (String)e.nextElement();
                String value = (String)definedProps.get(arg);
                project.setUserProperty(arg, value);
            }

            project.setUserProperty( "ant.file" , buildFile.getAbsolutePath() );

            // first use the ProjectHelper to create the project object
            // from the given build file.
            try {
                Class.forName("javax.xml.parsers.SAXParserFactory");
                ProjectHelper.configureProject(project, buildFile);
            } catch (NoClassDefFoundError ncdfe) {
                throw new BuildException("No JAXP compliant XML parser found. See http://java.sun.com/xml for the\nreference implementation.", ncdfe);
            } catch (ClassNotFoundException cnfe) {
                throw new BuildException("No JAXP compliant XML parser found. See http://java.sun.com/xml for the\nreference implementation.", cnfe);
            } catch (NullPointerException npe) {
                throw new BuildException("No JAXP compliant XML parser found. See http://java.sun.com/xml for the\nreference implementation.", npe);
            }

            // make sure that we have a target to execute
            if (targets.size() == 0) {
                targets.addElement(project.getDefaultTarget());
            }

            if (projectHelp) {
                printTargets(project);
            } else {
                // actually do some work
                project.executeTargets(targets);
            }
        }
        catch(RuntimeException exc) {
            error = exc;
            throw exc;
        }
        catch(Error err) {
            error = err;
            throw err;
        }
        finally {
            project.fireBuildFinished(error);
        }
    }

    protected void addBuildListeners(Project project) {

        // Add the default listener
        project.addBuildListener(createLogger());

        for (int i = 0; i < listeners.size(); i++) {
            String className = (String) listeners.elementAt(i);
            try {
                BuildListener listener =
                    (BuildListener) Class.forName(className).newInstance();
                project.addBuildListener(listener);
            }
            catch(Exception exc) {
                throw new BuildException("Unable to instantiate listener " + className, exc);
            }
        }
    }

    /**
     *  Creates the default build logger for sending build events to the ant log.
     */
    private BuildLogger createLogger() {
        BuildLogger logger = null;
        if (loggerClassname != null) {
            try {
                logger = (BuildLogger)(Class.forName(loggerClassname).newInstance());
            }
            catch (ClassCastException e) {
                System.err.println("The specified logger class " + loggerClassname +
                                         " does not implement the BuildLogger interface");
                throw new RuntimeException();
            }
            catch (Exception e) {
                System.err.println("Unable to instantiate specified logger class " +
                                           loggerClassname + " : " + e.getClass().getName());
                throw new RuntimeException();
            }
        }
        else {
            logger = new DefaultLogger();
        }

        logger.setMessageOutputLevel(msgOutputLevel);
        logger.setOutputPrintStream(out);
        logger.setErrorPrintStream(err);
        logger.setEmacsMode(emacsMode);

        return logger;
    }

    /**
     * Prints the usage of how to use this class to System.out
     */
    private static void printUsage() {
        String lSep = System.getProperty("line.separator");
        StringBuffer msg = new StringBuffer();
        msg.append("ant [options] [target [target2 [target3] ...]]" + lSep);
        msg.append("Options: " + lSep);
        msg.append("  -help                  print this message" + lSep);
        msg.append("  -projecthelp           print project help information" + lSep);
        msg.append("  -version               print the version information and exit" + lSep);
        msg.append("  -quiet                 be extra quiet" + lSep);
        msg.append("  -verbose               be extra verbose" + lSep);
        msg.append("  -debug                 print debugging information" + lSep);
        msg.append("  -emacs                 produce logging information without adornments" + lSep);
        msg.append("  -logfile <file>        use given file for log" + lSep);
        msg.append("  -logger <classname>    the class which is to perform logging" + lSep);
        msg.append("  -listener <classname>  add an instance of class as a project listener" + lSep);
        msg.append("  -buildfile <file>      use given buildfile" + lSep);
        msg.append("  -D<property>=<value>   use value for given property" + lSep);
        msg.append("  -find <file>           search for buildfile towards the root of the" + lSep);
        msg.append("                         filesystem and use it" + lSep);
        System.out.println(msg.toString());
    }

    private static void printVersion() {
        try {
            Properties props = new Properties();
            InputStream in =
                Main.class.getResourceAsStream("/org/apache/tools/ant/version.txt");
            props.load(in);
            in.close();

            String lSep = System.getProperty("line.separator");
            StringBuffer msg = new StringBuffer();
            msg.append("Ant version ");
            msg.append(props.getProperty("VERSION"));
            msg.append(" compiled on ");
            msg.append(props.getProperty("DATE"));
            msg.append(lSep);
            System.out.println(msg.toString());
        } catch (IOException ioe) {
            System.err.println("Could not load the version information.");
            System.err.println(ioe.getMessage());
        } catch (NullPointerException npe) {
            System.err.println("Could not load the version information.");
        }
    }

    /**
     * Print out a list of all targets in the current buildfile
     */
    private static void printTargets(Project project) {
        // find the target with the longest name
        int maxLength = 0;
        Enumeration ptargets = project.getTargets().elements();
        String targetName;
        String targetDescription;
        Target currentTarget;
        // split the targets in top-level and sub-targets depending
        // on the presence of a description
        Vector topNames = new Vector();
        Vector topDescriptions = new Vector();
        Vector subNames = new Vector();

        while (ptargets.hasMoreElements()) {
            currentTarget = (Target)ptargets.nextElement();
            targetName = currentTarget.getName();
            targetDescription = currentTarget.getDescription();
            // maintain a sorted list of targets
            if (targetDescription == null) {
                int pos = findTargetPosition(subNames, targetName);
                subNames.insertElementAt(targetName, pos);
            } else {
                int pos = findTargetPosition(topNames, targetName);
                topNames.insertElementAt(targetName, pos);
                topDescriptions.insertElementAt(targetDescription, pos);
                if (targetName.length() > maxLength) {
                    maxLength = targetName.length();
                }
            }
        }

        String defaultTarget = project.getDefaultTarget();
        if (defaultTarget != null && !"".equals(defaultTarget)) { // shouldn't need to check but...
            Vector defaultName = new Vector();
            Vector defaultDesc = null;
            defaultName.addElement(defaultTarget);

            int indexOfDefDesc = topNames.indexOf(defaultTarget);
            if (indexOfDefDesc >= 0) {
                defaultDesc.addElement(topDescriptions.elementAt(indexOfDefDesc));
            }
            printTargets(defaultName, defaultDesc, "Default target:", maxLength);

        }

        printTargets(topNames, topDescriptions, "Main targets:", maxLength);
        printTargets(subNames, null, "Subtargets:", 0);
    }

    /**
     * Search for the insert position to keep names a sorted list of Strings
     */
    private static int findTargetPosition(Vector names, String name) {
        int res = names.size();
        for (int i=0; i<names.size() && res == names.size(); i++) {
            if (name.compareTo((String)names.elementAt(i)) < 0) {
                res = i;
            }
        }
        return res;
    }

    /**
     * Output a formatted list of target names with an optional description
     */
    private static void printTargets(Vector names, Vector descriptions, String heading, int maxlen) {
        // now, start printing the targets and their descriptions
        String lSep = System.getProperty("line.separator");
        // got a bit annoyed that I couldn't find a pad function
        String spaces = "    ";
        while (spaces.length()<maxlen) {
            spaces += spaces;
        }
        StringBuffer msg = new StringBuffer();
        msg.append(heading + lSep + lSep);
        for (int i=0; i<names.size(); i++) {
            msg.append(" ");
            msg.append(names.elementAt(i));
            if (descriptions != null) {
                msg.append(spaces.substring(0, maxlen - ((String)names.elementAt(i)).length() + 2));
                msg.append(descriptions.elementAt(i));
            }
            msg.append(lSep);
        }
        System.out.println(msg.toString());
    }
}
