package org.apache.maven.plugin.changes;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.io.File;
import java.util.List;

import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugin.changes.schema.ChangesSchemaValidator;
import org.apache.maven.plugin.changes.schema.SchemaValidatorException;
import org.apache.maven.plugin.changes.schema.XmlValidationHandler;
import org.apache.maven.plugins.annotations.Component;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.xml.sax.SAXParseException;

/**
 * Goal which validate the <code>changes.xml</code> file.
 * 
 * @author Olivier Lamy
 * @version $Id$
 * @since 2.1
 */
@Mojo( name = "changes-validate", threadSafe = true )
public class ChangesValidatorMojo
    extends AbstractChangesMojo
{

    /**
     */
    @Component( role = ChangesSchemaValidator.class, hint = "default" )
    private ChangesSchemaValidator changesSchemaValidator;

    /**
     * The changes xsd version.
     */
    @Parameter( property = "changes.xsdVersion", defaultValue = "1.0.0" )
    private String changesXsdVersion;

    /**
     * Mojo failure if validation failed. If not and validation failed only a warning will be logged.
     */
    @Parameter( property = "changes.validate.failed", defaultValue = "false" )
    private boolean failOnError;

    /**
     * The path of the <code>changes.xml</code> file that will be converted into an HTML report.
     */
    @Parameter( property = "changes.xmlPath", defaultValue = "src/changes/changes.xml" )
    private File xmlPath;

    /**
     * @see org.apache.maven.plugin.Mojo#execute()
     */
    public void execute()
        throws MojoExecutionException, MojoFailureException
    {
        // Run only at the execution root
        if ( runOnlyAtExecutionRoot && !isThisTheExecutionRoot() )
        {
            getLog().info( "Skipping the changes validate in this project because it's not the Execution Root" );
        }
        else
        {
            if ( !xmlPath.exists() )
            {
                getLog().warn( "changes.xml file " + xmlPath.getAbsolutePath() + " does not exist." );
                return;
            }

            try
            {
                XmlValidationHandler xmlValidationHandler =
                    changesSchemaValidator.validateXmlWithSchema( xmlPath, changesXsdVersion, failOnError );
                boolean hasErrors = !xmlValidationHandler.getErrors().isEmpty();
                if ( hasErrors )
                {
                    logSchemaValidation( xmlValidationHandler.getErrors() );
                    if ( failOnError )
                    {
                        throw new MojoExecutionException( "changes.xml file " + xmlPath.getAbsolutePath()
                            + " is not valid, see previous errors." );
                    }
                    else
                    {
                        getLog().info( " skip previous validation errors due to failOnError=false." );
                    }
                }
            }
            catch ( SchemaValidatorException e )
            {
                if ( failOnError )
                {
                    throw new MojoExecutionException( "failed to validate changes.xml file " + xmlPath.getAbsolutePath()
                        + ": " + e.getMessage(), e );
                }
            }
        }
    }

    private void logSchemaValidation( List<SAXParseException> errors )
    {
        getLog().warn( "failed to validate changes.xml file " + xmlPath.getAbsolutePath() );
        getLog().warn( "validation errors: " );
        for ( SAXParseException error : errors )
        {
            getLog().warn( error.getMessage() );
        }
    }

}