/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 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.taskdefs;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.filters.util.ChainReaderHelper;
import org.apache.tools.ant.types.FilterChain;

/**
 * Load a file's contents as Ant properties.
 *
 * @author Magesh Umasankar
 * @since Ant 1.5
 * @ant.task category="utility"
 */
public final class LoadProperties extends Task {

    /**
     * Source file
     */
    private File srcFile = null;

    /**
     * Holds filterchains
     */
    private final Vector filterChains = new Vector();

    /**
     * Encoding to use for filenames, defaults to the platform's default
     * encoding.
     */
    private String encoding = null;

    /**
     * Sets the file to load.
     *
     * @param srcFile The new SrcFile value
     */
    public final void setSrcFile(final File srcFile) {
        this.srcFile = srcFile;
    }

    /**
     * Encoding to use for input, defaults to the platform's default
     * encoding. <p>
     *
     * For a list of possible values see <a href="http://java.sun.com/products/jdk/1.2/docs/guide/internat/encoding.doc.html">
     * http://java.sun.com/products/jdk/1.2/docs/guide/internat/encoding.doc.html
     * </a>.</p>
     *
     * @param encoding The new Encoding value
     */

    public final void setEncoding(final String encoding) {
        this.encoding = encoding;
    }

    /**
     * read in a source file's contents and load them up as Ant properties
     *
     * @exception BuildException if something goes wrong with the build
     */
    public final void execute() throws BuildException {
        //validation
        if (srcFile == null) {
            throw new BuildException("Source file not defined.");
        }

        if (!srcFile.exists()) {
            throw new BuildException("Source file does not exist.");
        }

        if (!srcFile.isFile()) {
            throw new BuildException("Source file is not a file.");
        }

        FileInputStream fis = null;
        BufferedInputStream bis = null;
        Reader instream = null;

        try {
            final long len = srcFile.length();
            final int size = (int) len;

            //open up the file
            fis = new FileInputStream(srcFile);
            bis = new BufferedInputStream(fis);
            if (encoding == null) {
                instream = new InputStreamReader(bis);
            } else {
                instream = new InputStreamReader(bis, encoding);
            }

            ChainReaderHelper crh = new ChainReaderHelper();
            crh.setBufferSize(size);
            crh.setPrimaryReader(instream);
            crh.setFilterChains(filterChains);
            crh.setProject(getProject());
            instream = crh.getAssembledReader();

            String text = crh.readFully(instream);

            if (text != null) {
                if (!text.endsWith("\n")) {
                    text = text + "\n";
                }

                ByteArrayInputStream tis = null;
                if ( encoding == null ) {
                    tis = new ByteArrayInputStream(text.getBytes());
                } else {
                    tis = new ByteArrayInputStream(text.getBytes(encoding));
                }
                final Properties props = new Properties();
                props.load(tis);
                final Enumeration e = props.keys();
                while (e.hasMoreElements()) {
                    final String key = (String) e.nextElement();
                    final String value = props.getProperty(key);
                    if (key != null && value != null
                            && value.trim().length() > 0) {
                        getProject().setNewProperty(key, value);
                    }
                }
                tis.close();
            }

        } catch (final IOException ioe) {
            final String message = "Unable to load file: " + ioe.toString();
            throw new BuildException(message, ioe, getLocation());
        } catch (final BuildException be) {
            throw be;
        } finally {
            try {
                if (fis != null) {
                    fis.close();
                }
            } catch (IOException ioex) {
                //ignore
            }
        }
    }

    /**
     * Adds a FilterChain.
     */
    public final void addFilterChain(FilterChain filter) {
        filterChains.addElement(filter);
    }

//end class
}