/*

* Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  

*

*/

package com.nokia.helium.sysdef.ant.taskdefs;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.util.Map;

import javax.xml.transform.ErrorListener;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerException;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.stream.StreamResult;

import javax.xml.transform.stream.StreamSource;

import org.apache.tools.ant.BuildException;

import org.apache.tools.ant.Project;

import org.apache.tools.ant.Task;

/**

 * This is the base class for manipulating Sysdef v3 files using XML Stylesheet. 

 * The implementation/interface is not frozen yet. It is morelikely going to

 * change in the future, depending of the underlaying implementation.

 * 

 */

public abstract class AbstractSydefTask extends Task implements ErrorListener {

    private File srcFile;

    private File destFile;

    private File epocroot;

    /**

     * Get the source file.

     * @return

     */

    public File getSrcFile() {

        return srcFile;

    }

    /**

     * Defines the location of the source system definition file. 

     * @param srcfile

     * @ant.required

     */

    public void setSrcFile(File srcfile) {

        this.srcFile = srcfile;

    }

    /**

     * Get the location of the output file. 

     * @return

     */

    public File getDestFile() {

        return destFile;

    }

    /**

     * The the name of the destination file.

     * @param destfile

     * @ant.required

     */

    public void setDestFile(File destfile) {

        this.destFile = destfile;

    }

    /**

     * Get the epocroot.

     * If epocroot is not set by the user it return the value from the EPOCROOT environment variable.

     * If the EPOCROOT environment variable is not defined then a BuildException is thrown.

     * @return the epocroot location as a File object.

     */

    public File getEpocroot() {

        if (epocroot == null) {

            if (System.getenv("EPOCROOT") != null) {

                return new File(System.getenv("EPOCROOT"));

            }

            else {

                throw new BuildException("'epocroot' attribute has not been defined.");

            }

        }

        return epocroot;

    }

    /**

     * Location of the EPOCROOT.

     * @ant.not-required By default the EPOCROOT environment variable is used.

     * @param epocroot path to the epocroot.

     */

    public void setEpocroot(File epocroot) {

        this.epocroot = epocroot;

    }

    /**

     * Shall we fail the build on error.

     * @return is the task should failonerror.

     */

    public boolean isFailOnError() {

        return failOnError;

    }

    /**

     * @param failonerror

     * @ant.not-required Default is true.

     */

    public void setFailOnError(boolean failonerror) {

        this.failOnError = failonerror;

    }

    /**

     * This method should be defined by the implementing class

     * to define the location of the XSLT file.

     * @return the XSLT file location.

     */

    /**

     * Check if required attribute have been configured correctly.

     * If not the method will raise a BuildException.

     */

    protected void check() {

        if (getSrcFile() == null) {

            throw new BuildException("'srcfile' attribute is not defined");

        }

        if (getDestFile() == null) {

            throw new BuildException("'destfile' attribute is not defined");

        }

        File xslt = getXsl();

        if (!xslt.exists()) {

            throw new BuildException("Could not find " + xslt);

        }        

        if (!getSrcFile().exists()) {

            throw new BuildException("Could not find source file " + srcFile);

        }        

    }

    /**

     * Transform the srcfile using the stylesheet provided by getXsl. The data parameters are

     * passed to the template engine. The result is save to the destfile.

     * 

     * @param data a set of key/value to pass to the XSLT engine.

     */

    public void transform(Map<String, String> data) {

        check();

        if (getDestFile().exists()) {

            log("Deleting previous output file: " + destFile, Project.MSG_DEBUG);

            getDestFile().delete();

        }

        FileOutputStream output = null;        

        try {

            output = new FileOutputStream(getDestFile());

            TransformerFactory factory = TransformerFactory.newInstance();

            Transformer transformer = factory.newTransformer(new StreamSource(getXsl()));

            transformer.setParameter("path", getSrcFile());

            for (Map.Entry<String, String> entry : data.entrySet()) {

                transformer.setParameter(entry.getKey(), entry.getValue());

            }

            transformer.setErrorListener(this);        

            transformer.transform(new StreamSource(getSrcFile()), new StreamResult(

                    output));

            output.close();

        } catch (FileNotFoundException exc) {

            // deleting the intermediate file in case of error.

            if (getDestFile().exists()) {

                // closing current output stream, so we can delete the file

                try {

                    if (output != null) {

                        output.close();

                    }

                } catch (IOException ioe) {

                    // we should just ignore that error.

                    log(ioe, Project.MSG_DEBUG);

                }

                log("Deleting " + destFile + " because an error occured.", Project.MSG_INFO);

                getDestFile().delete();

            }

            // Raising the error to Ant.

            throw new BuildException(exc.toString());

        } catch (TransformerConfigurationException exc) {

            // deleting the intermediate file in case of error.

            if (destFile.exists()) {

                // closing current output stream, so we can delete the file

                try {

                    if (output != null) {

                        output.close();

                    }

                } catch (IOException ioe) {

                    // we should just ignore that error.

                    log(ioe, Project.MSG_DEBUG);

                }

                log("Deleting " + destFile + " because an error occured.", Project.MSG_INFO);

                getDestFile().delete();

            }

            // Raising the error to Ant.

            throw new BuildException(exc.toString());

        } catch (TransformerException exc) {

            // deleting the intermediate file in case of error.

            if (getDestFile().exists()) {

                // closing current output stream, so we can delete the file

                try {

                    if (output != null) {

                        output.close();

                    }

                } catch (IOException ioe) {

                    // we should just ignore that error.

                    log(ioe, Project.MSG_DEBUG);

                }

                log("Deleting " + getDestFile() + " because an error occured.", Project.MSG_INFO);

                getDestFile().delete();

            }

            // Raising the error to Ant.

            throw new BuildException(exc.toString());

        } catch (IOException e) {

            // we should just ignore that error, error while closing the file.

            log(e.getMessage(), Project.MSG_DEBUG);

        }

    }

    /**

     * {@inheritDoc}

     * Reports errors to the Ant logging system of throw the exception if the task

     * is set to failonerror.

     */

    @Override

    public void error(TransformerException message) throws TransformerException {

        if (this.isFailOnError()) {

            throw message;

        } else {

            log("ERROR: " + message.getMessageAndLocation(), Project.MSG_ERR);            

        }

    }

    /**

     * {@inheritDoc}

     * Fails the task in case of fatal error. The is nothing we can do about that.

     */

    @Override

    public void fatalError(TransformerException message) throws TransformerException {

        log("ERROR: " + message.getMessageAndLocation(), Project.MSG_ERR);

        throw message;

    }

    /**

     * {@inheritDoc}

     * Reports errors to the Ant logging system of throw the exception if the task

     * is set to failonerror.

     */

    @Override

    public void warning(TransformerException message) throws TransformerException {

            throw message;

        } else {

            log("WARNING: " + message.getMessageAndLocation(), Project.MSG_WARN);

        }

    }

}