/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 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
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 *
 * 5. Products derived from this software may not be called "Apache"
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * 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.taskdefs.optional;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.taskdefs.MatchingTask;
import org.apache.tools.ant.types.Commandline;
import org.apache.tools.ant.types.Mapper;
import org.apache.tools.ant.util.FileNameMapper;
import org.apache.tools.ant.util.IdentityMapper;
import org.apache.tools.ant.util.SourceFileScanner;

import java.io.File;

/**
 * Convert files from native encodings to ascii.
 *
 * @author <a href="asudell@acm.org">Drew Sudell</a>
 * @author <a href="mailto:stefan.bodewig@epost.de">Stefan Bodewig</a>
 */
public class Native2Ascii extends MatchingTask {

    private boolean reverse = false;  // convert from ascii back to native
    private String encoding = null;   // encoding to convert to/from
    private File srcDir = null;       // Where to find input files
    private File destDir = null;      // Where to put output files
    private String extension = null;  // Extension of output files if different

    private Mapper mapper;

    /**
     * Flag the conversion to run in the reverse sense,
     * that is Ascii to Native encoding.
     * 
     * @param reverse True if the conversion is to be reversed,
     *                otherwise false;
     */
    public void setReverse(boolean reverse){
        this.reverse = reverse;
    }

    /**
     * Set the encoding to translate to/from.
     * If unset, the default encoding for the JVM is used.
     *
     * @param encoding String containing the name of the Native 
     *                 encoding to convert from or to.
     */
    public void setEncoding(String encoding){
        this.encoding = encoding;
    }

    /**
     * Set the source directory in which to find files to convert.
     *
     * @param srcDir Direcrory to find input file in.
     */
    public void setSrc(File srcDir){
        this.srcDir = srcDir;
    }


    /**
     * Set the destination dirctory to place converted files into.
     *
     * @param destDir directory to place output file into.
     */
    public void setDest(File destDir){
        this.destDir = destDir;
    }

    /**
     * Set the extension which converted files should have.
     * If unset, files will not be renamed.
     *
     * @param ext File extension to use for converted files.
     */
    public void setExt(String ext){
        this.extension = ext;
    }

    /**
     * Defines the FileNameMapper to use (nested mapper element).
     */
    public Mapper createMapper() throws BuildException {
        if (mapper != null) {
            throw new BuildException("Cannot define more than one mapper",
                                     location);
        }
        mapper = new Mapper(project);
        return mapper;
    }

    public void execute() throws BuildException {

        Commandline baseCmd = null;      // the common portion of our cmd line
        DirectoryScanner scanner = null; // Scanner to find our inputs
        String[] files;                  // list of files to process

        // default srcDir to basedir
        if (srcDir == null){
            srcDir = project.resolveFile(".");
        }

        // Require destDir
        if (destDir == null){
            throw new BuildException("The dest attribute must be set.");
        }

        // if src and dest dirs are the same, require the extension
        // to be set, so we don't stomp every file.  One could still
        // include a file with the same extension, but ....
        if (srcDir.equals(destDir) && extension == null && mapper == null){
            throw new BuildException("The ext attribute or a mapper must be set if"
                                     + " src and dest dirs are the same.");
        }

        FileNameMapper m = null;
        if (mapper == null) {
            if (extension == null) {
                m = new IdentityMapper();
            } else {
                m = new ExtMapper();
            }
        } else {
            m = mapper.getImplementation();
        }
        
        scanner = getDirectoryScanner(srcDir);
        files = scanner.getIncludedFiles();
        SourceFileScanner sfs = new SourceFileScanner(this);
        files = sfs.restrict(files, srcDir, destDir, m);
        int count = files.length;
        if (count == 0) {
            return;
        }
        String message = "Converting "+ count + " file"
            + (count != 1 ? "s" : "") + " from ";
        log(message + srcDir + " to " + destDir);
        for (int i = 0; i < files.length; i++){
            convert(files[i], m.mapFileName(files[i])[0]);
        }
    }

    /**
     * Convert a single file.
     *
     * @param fileName Name of the file to convert (relative to srcDir).
     */
    private void convert(String srcName, String destName) throws BuildException {

        Commandline cmd = new Commandline();  // Command line to run
        File srcFile;                         // File to convert
        File destFile;                        // where to put the results

        // Set up the basic args (this could be done once, but
        // it's cleaner here)
        if (reverse){
            cmd.createArgument().setValue("-reverse");
        }

        if (encoding != null){
            cmd.createArgument().setValue("-encoding");
            cmd.createArgument().setValue(encoding);
        }

        // Build the full file names
        srcFile = new File(srcDir, srcName);
        destFile = new File(destDir, destName);

        cmd.createArgument().setFile(srcFile);
        cmd.createArgument().setFile(destFile);
        // Make sure we're not about to clobber something
        if (srcFile.equals(destFile)){
            throw new BuildException("file " + srcFile 
                                     + " would overwrite its self");
        }

        // Make intermediate directories if needed
        // XXX JDK 1.1 dosen't have File.getParentFile,
        String parentName = destFile.getParent();
        if (parentName != null){
            File parentFile = new File(parentName);
            
            if ((! parentFile.exists()) && ( ! parentFile.mkdirs())){
                throw new BuildException("cannot create parent directory "
                                         + parentName);
            }
        }
                        
        log("converting " + srcName, Project.MSG_VERBOSE);
        sun.tools.native2ascii.Main n2a
            = new sun.tools.native2ascii.Main();
        if(! n2a.convert(cmd.getArguments())){
            throw new BuildException("conversion failed");
        }
    }

    private class ExtMapper implements FileNameMapper {

        public void setFrom(String s) {}
        public void setTo(String s) {}

        public String[] mapFileName(String fileName) {
            int lastDot = fileName.lastIndexOf('.');
            if (lastDot >= 0) {
                return new String[] {fileName.substring(0, lastDot) + extension};
            } else {
                return new String[] {fileName + extension};
            }
        }
    }
}
