/*
 * 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.
 *
 * $Header:$
 */
package org.apache.beehive.netui.compiler;

import org.apache.beehive.netui.compiler.typesystem.declaration.TypeDeclaration;
import org.apache.beehive.netui.compiler.typesystem.declaration.MemberDeclaration;
import org.apache.beehive.netui.compiler.typesystem.declaration.AnnotationInstance;
import org.apache.beehive.netui.compiler.typesystem.declaration.AnnotationTypeElementDeclaration;
import org.apache.beehive.netui.compiler.typesystem.declaration.AnnotationValue;
import org.apache.beehive.netui.compiler.typesystem.type.TypeInstance;
import org.apache.beehive.netui.compiler.typesystem.env.CoreAnnotationProcessorEnv;
import org.apache.beehive.netui.compiler.model.StrutsApp;
import org.apache.beehive.netui.compiler.model.XmlModelWriter;
import org.apache.beehive.netui.compiler.model.XmlModelWriterException;
import org.w3c.dom.Element;

import java.util.Map;
import java.util.Iterator;
import java.util.List;
import java.util.Date;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;

public class AnnotationToXML
{
    private static final String ANNOTATIONS_FILE_PREFIX = "annotations";

    private XmlModelWriter _xw;
    private TypeDeclaration _typeDecl;

    public AnnotationToXML(TypeDeclaration typeDecl)
            throws IOException, XmlModelWriterException
    {
        _typeDecl = typeDecl;
        String typeName = typeDecl.getQualifiedName();
        StringBuffer comment = new StringBuffer(" Generated from ");
        comment.append(typeName);
        comment.append( " on " ).append( new Date().toString() ).append( ' ' );
        _xw = new XmlModelWriter(null, "processed-annotations", null, null, comment.toString());
        _xw.addElementWithText(_xw.getRootElement(), "type-name", typeName);
    }

    public void include( MemberDeclaration memberDecl, AnnotationInstance annotation )
    {
        String name = memberDecl instanceof TypeDeclaration
                      ? ( ( TypeDeclaration ) memberDecl ).getQualifiedName()
                      : memberDecl.getSimpleName();
        Element annotatedElement = _xw.addElement(_xw.getRootElement(), "annotated-element");
        _xw.addElementWithText(annotatedElement, "element-name", name);
        Element xmlAnnotation = _xw.addElement(annotatedElement, "annotation");
        include( xmlAnnotation, annotation );
    }

    private void include( Element xmlAnnotation, AnnotationInstance annotation )
    {
        String annotationName = annotation.getAnnotationType().getAnnotationTypeDeclaration().getQualifiedName();
        _xw.addElementWithText(xmlAnnotation, "annotation-name", annotationName);

        Map elementValues = annotation.getElementValues();

        for ( Iterator i = elementValues.entrySet().iterator(); i.hasNext(); )
        {
            Map.Entry entry = ( Map.Entry ) i.next();
            AnnotationTypeElementDeclaration elementDecl = ( AnnotationTypeElementDeclaration ) entry.getKey();
            AnnotationValue annotationValue = ( AnnotationValue ) entry.getValue();

            String name = elementDecl.getSimpleName();
            Object value = annotationValue.getValue();
            Element xmlAttr = _xw.addElement(xmlAnnotation, "annotation-attribute");
            _xw.addElementWithText(xmlAttr, "attribute-name", name);

            if ( value instanceof List )
            {
                for ( Iterator j = ( ( List ) value ).iterator(); j.hasNext(); )
                {
                    Object o = j.next();
                    assert o instanceof AnnotationValue : o.getClass().getName();
                    Object listVal = ( ( AnnotationValue ) o ).getValue();

                    // we only handle lists of annotations at the moment
                    assert listVal instanceof AnnotationInstance : listVal.getClass().getName();
                    include(_xw.addElement(xmlAttr, "annotation-value"), (AnnotationInstance) listVal);
                }
            }
            else
            {
                // we only support a few types at the moment
                assert value instanceof TypeInstance || value instanceof String : value.getClass().getName();
                _xw.addElementWithText(xmlAttr, "string-value", value.toString());
            }
        }
    }

    public void writeXml( Diagnostics diagnostics, CoreAnnotationProcessorEnv env )
            throws IOException, XmlModelWriterException
    {
        String outputFilePath = getFilePath(_typeDecl);
        File outputFile = new File(outputFilePath);
        PrintWriter writer = env.getFiler().createTextFile(outputFile);

        try {
            _xw.simpleFastWrite(writer);
        } finally {
            writer.close();
        }
    }
    
    public static String getFilePath(TypeDeclaration typeDecl)
    {
        String typeName = typeDecl.getQualifiedName();
        return StrutsApp.getOutputFileURI( ANNOTATIONS_FILE_PREFIX, typeName, false );
    }
}