/*
 * Copyright  2000-2004 The Apache Software Foundation
 *
 *  Licensed 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.
 *
 */

package org.apache.tools.ant.taskdefs.optional.javacc;

import java.io.File;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.taskdefs.LogStreamHandler;
import org.apache.tools.ant.types.Commandline;
import org.apache.tools.ant.types.CommandlineJava;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.util.JavaEnvUtils;

/**
 * Runs the JJTree compiler compiler.
 *
 */
public class JJTree extends Task {

    // keys to optional attributes
    private static final String OUTPUT_FILE       = "OUTPUT_FILE";
    private static final String BUILD_NODE_FILES  = "BUILD_NODE_FILES";
    private static final String MULTI             = "MULTI";
    private static final String NODE_DEFAULT_VOID = "NODE_DEFAULT_VOID";
    private static final String NODE_FACTORY      = "NODE_FACTORY";
    private static final String NODE_SCOPE_HOOK   = "NODE_SCOPE_HOOK";
    private static final String NODE_USES_PARSER  = "NODE_USES_PARSER";
    private static final String STATIC            = "STATIC";
    private static final String VISITOR           = "VISITOR";

    private static final String NODE_PACKAGE      = "NODE_PACKAGE";
    private static final String VISITOR_EXCEPTION = "VISITOR_EXCEPTION";
    private static final String NODE_PREFIX       = "NODE_PREFIX";

    private final Hashtable optionalAttrs = new Hashtable();

    private String outputFile = null;

    private static final String DEFAULT_SUFFIX = ".jj";

    // required attributes
    private File outputDirectory = null;
    private File target          = null;
    private File javaccHome      = null;

    private CommandlineJava cmdl = new CommandlineJava();


    /**
     * Sets the BUILD_NODE_FILES grammar option.
     */
    public void setBuildnodefiles(boolean buildNodeFiles) {
        optionalAttrs.put(BUILD_NODE_FILES, new Boolean(buildNodeFiles));
    }

    /**
     * Sets the MULTI grammar option.
     */
    public void setMulti(boolean multi) {
        optionalAttrs.put(MULTI, new Boolean(multi));
    }

    /**
     * Sets the NODE_DEFAULT_VOID grammar option.
     */
    public void setNodedefaultvoid(boolean nodeDefaultVoid) {
        optionalAttrs.put(NODE_DEFAULT_VOID, new Boolean(nodeDefaultVoid));
    }

    /**
     * Sets the NODE_FACTORY grammar option.
     */
    public void setNodefactory(boolean nodeFactory) {
        optionalAttrs.put(NODE_FACTORY, new Boolean(nodeFactory));
    }

    /**
     * Sets the NODE_SCOPE_HOOK grammar option.
     */
    public void setNodescopehook(boolean nodeScopeHook) {
        optionalAttrs.put(NODE_SCOPE_HOOK, new Boolean(nodeScopeHook));
    }

    /**
     * Sets the NODE_USES_PARSER grammar option.
     */
    public void setNodeusesparser(boolean nodeUsesParser) {
        optionalAttrs.put(NODE_USES_PARSER, new Boolean(nodeUsesParser));
    }

    /**
     * Sets the STATIC grammar option.
     */
    public void setStatic(boolean staticParser) {
        optionalAttrs.put(STATIC, new Boolean(staticParser));
    }

    /**
     * Sets the VISITOR grammar option.
     */
    public void setVisitor(boolean visitor) {
        optionalAttrs.put(VISITOR, new Boolean(visitor));
    }

    /**
     * Sets the NODE_PACKAGE grammar option.
     */
    public void setNodepackage(String nodePackage) {
        optionalAttrs.put(NODE_PACKAGE, new String(nodePackage));
    }

    /**
     * Sets the VISITOR_EXCEPTION grammar option.
     */
    public void setVisitorException(String visitorException) {
        optionalAttrs.put(VISITOR_EXCEPTION, new String(visitorException));
    }

    /**
     * Sets the NODE_PREFIX grammar option.
     */
    public void setNodeprefix(String nodePrefix) {
        optionalAttrs.put(NODE_PREFIX, new String(nodePrefix));
    }

    /**
     * The directory to write the generated JavaCC grammar and node files to.
     * If not set, the files are written to the directory
     * containing the grammar file.
     */
    public void setOutputdirectory(File outputDirectory) {
        this.outputDirectory = outputDirectory;
    }

    /**
     * The outputfile to write the generated JavaCC grammar file to.
     * If not set, the file is written with the same name as
     * the JJTree grammar file with a suffix .jj.
     */
    public void setOutputfile(String outputFile) {
        this.outputFile = outputFile;
    }

    /**
     * The jjtree grammar file to process.
     */
    public void setTarget(File target) {
        this.target = target;
    }

    /**
     * The directory containing the JavaCC distribution.
     */
    public void setJavacchome(File javaccHome) {
        this.javaccHome = javaccHome;
    }

    public JJTree() {
        cmdl.setVm(JavaEnvUtils.getJreExecutable("java"));
    }

    public void execute() throws BuildException {

        // load command line with optional attributes
        Enumeration iter = optionalAttrs.keys();
        while (iter.hasMoreElements()) {
            String name  = (String) iter.nextElement();
            Object value = optionalAttrs.get(name);
            cmdl.createArgument().setValue("-" + name + ":" + value.toString());
        }

        if (target == null || !target.isFile()) {
            throw new BuildException("Invalid target: " + target);
        }

        File javaFile = null;

        // use the directory containing the target as the output directory
        if (outputDirectory == null) {
            // convert backslashes to slashes, otherwise jjtree will
            // put this as comments and this seems to confuse javacc
            cmdl.createArgument().setValue("-OUTPUT_DIRECTORY:"
                                           + getDefaultOutputDirectory());

            javaFile = new File(createOutputFileName(target, outputFile,
                                                     null));
        } else {
            if (!outputDirectory.isDirectory()) {
                throw new BuildException("'outputdirectory' " + outputDirectory
                                         + " is not a directory.");
            }

            // convert backslashes to slashes, otherwise jjtree will
            // put this as comments and this seems to confuse javacc
            cmdl.createArgument().setValue("-OUTPUT_DIRECTORY:"
                                           + outputDirectory.getAbsolutePath()
                                             .replace('\\', '/'));

            javaFile = new File(createOutputFileName(target, outputFile,
                                                     outputDirectory
                                                     .getPath()));
        }

        if (javaFile.exists()
            && target.lastModified() < javaFile.lastModified()) {
            log("Target is already built - skipping (" + target + ")",
                Project.MSG_VERBOSE);
            return;
        }

        if (outputFile != null) {
            cmdl.createArgument().setValue("-" + OUTPUT_FILE + ":"
                                           + outputFile.replace('\\', '/'));
        }

        cmdl.createArgument().setValue(target.getAbsolutePath());

        cmdl.setClassname(JavaCC.getMainClass(javaccHome,
                                              JavaCC.TASKDEF_TYPE_JJTREE));

        final Path classpath = cmdl.createClasspath(getProject());
        final File javaccJar = JavaCC.getArchiveFile(javaccHome);
        classpath.createPathElement().setPath(javaccJar.getAbsolutePath());
        classpath.addJavaRuntime();

        final Commandline.Argument arg = cmdl.createVmArgument();
        arg.setValue("-mx140M");
        arg.setValue("-Dinstall.root=" + javaccHome.getAbsolutePath());

        final Execute process =
            new Execute(new LogStreamHandler(this,
                                             Project.MSG_INFO,
                                             Project.MSG_INFO),
                        null);
        log(cmdl.describeCommand(), Project.MSG_VERBOSE);
        process.setCommandline(cmdl.getCommandline());

        try {
            if (process.execute() != 0) {
                throw new BuildException("JJTree failed.");
            }
        } catch (IOException e) {
            throw new BuildException("Failed to launch JJTree", e);
        }
    }

    private String createOutputFileName(File target, String optionalOutputFile,
                                        String outputDirectory) {
        optionalOutputFile = validateOutputFile(optionalOutputFile,
                                                outputDirectory);
        String jjtreeFile = target.getAbsolutePath().replace('\\', '/');

        if ((optionalOutputFile == null) || optionalOutputFile.equals("")) {
            int filePos = jjtreeFile.lastIndexOf("/");

            if (filePos >= 0) {
                jjtreeFile = jjtreeFile.substring(filePos + 1);
            }

            int suffixPos = jjtreeFile.lastIndexOf('.');

            if (suffixPos == -1) {
                optionalOutputFile = jjtreeFile + DEFAULT_SUFFIX;
            } else {
                String currentSuffix = jjtreeFile.substring(suffixPos);

                if (currentSuffix.equals(DEFAULT_SUFFIX)) {
                    optionalOutputFile = jjtreeFile + DEFAULT_SUFFIX;
                } else {
                    optionalOutputFile = jjtreeFile.substring(0, suffixPos)
                        + DEFAULT_SUFFIX;
                }
            }
        }

        if ((outputDirectory == null) || outputDirectory.equals("")) {
            outputDirectory = getDefaultOutputDirectory();
        }

        return (outputDirectory + "/" + optionalOutputFile).replace('\\', '/');
    }

 /*
  * Not used anymore
    private boolean isAbsolute(String fileName) {
        return (fileName.startsWith("/") || (new File(fileName).isAbsolute()));
    }
*/
    /**
     * When running JJTree from an Ant taskdesk the -OUTPUT_DIRECTORY must
     * always be set. But when -OUTPUT_DIRECTORY is set, -OUTPUT_FILE is
     * handled as if relative of this -OUTPUT_DIRECTORY. Thus when the
     * -OUTPUT_FILE is absolute or contains a drive letter we have a problem.
     *
     * @param outputFile
     * @param outputDirectory
     * @return
     * @throws BuildException
     */
    private String validateOutputFile(String outputFile,
                                      String outputDirectory)
        throws BuildException {
        if (outputFile == null) {
            return null;
        }

        if ((outputDirectory == null)
            && (outputFile.startsWith("/") || outputFile.startsWith("\\"))) {
            String relativeOutputFile = makeOutputFileRelative(outputFile);
            setOutputfile(relativeOutputFile);

            return relativeOutputFile;
        }

        String root = getRoot(new File(outputFile)).getAbsolutePath();

        if ((root.length() > 1)
            && outputFile.startsWith(root.substring(0, root.length() - 1))) {
            throw new BuildException("Drive letter in 'outputfile' not "
                                     + "supported: " + outputFile);
        }

        return outputFile;
    }

    private String makeOutputFileRelative(String outputFile) {
        StringBuffer relativePath = new StringBuffer();
        String defaultOutputDirectory = getDefaultOutputDirectory();
        int nextPos = defaultOutputDirectory.indexOf('/');
        int startPos = nextPos + 1;

        while (startPos > -1 && startPos < defaultOutputDirectory.length()) {
            relativePath.append("/..");
            nextPos = defaultOutputDirectory.indexOf('/', startPos);

            if (nextPos == -1) {
                startPos = nextPos;
            } else {
                startPos = nextPos + 1;
            }
        }

        relativePath.append(outputFile);

        return relativePath.toString();
    }

    private String getDefaultOutputDirectory() {
        return getProject().getBaseDir().getAbsolutePath().replace('\\', '/');
    }

    /**
     * Determine root directory for a given file.
     *
     * @param file
     * @return file's root directory
     */
    private File getRoot(File file) {
        File root = file.getAbsoluteFile();

        while (root.getParent() != null) {
            root = root.getParentFile();
        }

        return root;
    }
}