/*
 * 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.
 */

package org.apache.axis2.databinding.utils.reader;

import javax.xml.namespace.NamespaceContext;
import javax.xml.namespace.QName;
import javax.xml.stream.Location;
import javax.xml.stream.XMLStreamException;

public class NullXMLStreamReader implements ADBXMLStreamReader {

    private QName outerQName = null;


    private static final int START_ELEMENT_STATE = 1;
    private static final int END_ELEMENT_STATE = 2;


    private static final QName NIL_QNAME =
            new QName("http://www.w3.org/2001/XMLSchema-instance", "nil", "xsi");
    private static final String NIL_VALUE_TRUE = "true";

    private int currentState = START_ELEMENT;

    public NullXMLStreamReader(QName outerQName) {
        this.outerQName = outerQName;
    }

    public Object getProperty(String key) throws IllegalArgumentException {
        //since optimization is a global property
        //we've to implement it everywhere
        if (OPTIMIZATION_ENABLED.equals(key)) {
            return Boolean.TRUE;
        } else {
            return null;
        }
    }

    public int next() throws XMLStreamException {
        int returnEvent = START_DOCUMENT;
        switch (currentState) {
            case START_ELEMENT_STATE:
                currentState = END_ELEMENT_STATE;
                returnEvent = END_ELEMENT;
                break;
            case END_ELEMENT_STATE:
                throw new XMLStreamException("parser completed!");

        }

        return returnEvent;
    }

    public void require(int i, String string, String string1) throws XMLStreamException {
        //nothing
    }

    public String getElementText() throws XMLStreamException {
        return null;
    }

    public int nextTag() throws XMLStreamException {
        throw new UnsupportedOperationException();
    }

    public boolean hasNext() throws XMLStreamException {
        return (currentState != END_ELEMENT_STATE);

    }

    public void close() throws XMLStreamException {
        //do nothing
    }

    public String getNamespaceURI(String string) {
        if (outerQName.getPrefix() != null &&
                outerQName.getPrefix().equals(string)) {
            return outerQName.getNamespaceURI();
        } else {
            return null;
        }
    }

    public boolean isStartElement() {
        return (currentState == START_ELEMENT_STATE);
    }

    public boolean isEndElement() {
        return (currentState == END_ELEMENT_STATE);
    }

    public boolean isCharacters() {
        return false;
    }

    public boolean isWhiteSpace() {
        return false;
    }

    public String getAttributeValue(String string, String string1) {
        if (string == null) {//null namespace - ignore it
            if (NIL_QNAME.getLocalPart().equals(string1)) {
                return NIL_VALUE_TRUE;
            }
        }
        return null;
    }

    public int getAttributeCount() {
        return 1;
    }

    public QName getAttributeName(int i) {
        return (i == 0) ? NIL_QNAME : null;
    }

    public String getAttributeNamespace(int i) {
        return (i == 0) ? NIL_QNAME.getNamespaceURI() : null;
    }

    public String getAttributeLocalName(int i) {
        return (i == 0) ? NIL_QNAME.getLocalPart() : null;
    }

    public String getAttributePrefix(int i) {
        return (i == 0) ? NIL_QNAME.getPrefix() : null;
    }

    public String getAttributeType(int i) {
        return null;
    }

    public String getAttributeValue(int i) {
        return (i == 0) ? NIL_VALUE_TRUE : null;
    }

    public boolean isAttributeSpecified(int i) {
        return (i == 0);
    }

    public int getNamespaceCount() {
        return 0;
    }

    public String getNamespacePrefix(int i) {
        return null;
    }

    public String getNamespaceURI(int i) {
        return null;
    }

    public NamespaceContext getNamespaceContext() {
        throw new UnsupportedOperationException();
    }

    public int getEventType() {
        int returnEvent = START_DOCUMENT;
        switch (currentState) {
            case START_ELEMENT_STATE:
                returnEvent = START_ELEMENT;
                break;
            case END_ELEMENT_STATE:
                returnEvent = END_ELEMENT;
                break;

        }
        return returnEvent;
    }

    public String getText() {
        return null;
    }

    public char[] getTextCharacters() {
        return new char[0];  //To change body of implemented methods use File | Settings | File Templates.
    }

    public int getTextCharacters(int i, char[] chars, int i1, int i2) throws XMLStreamException {
        return 0;
    }

    public int getTextStart() {
        return 0;
    }

    public int getTextLength() {
        return 0;
    }

    public String getEncoding() {
        return null;
    }

    public boolean hasText() {
        return false;
    }

    public Location getLocation() {
        return new Location() {
            public int getLineNumber() {
                return 0;
            }

            public int getColumnNumber() {
                return 0;
            }

            public int getCharacterOffset() {
                return 0;
            }

            public String getPublicId() {
                return null;
            }

            public String getSystemId() {
                return null;
            }
        };
    }

    public QName getName() {
        return outerQName;
    }

    public String getLocalName() {
        return outerQName.getLocalPart();
    }

    public boolean hasName() {
        return true;
    }

    public String getNamespaceURI() {
        return outerQName.getNamespaceURI();
    }

    public String getPrefix() {
        return outerQName.getPrefix();
    }

    public String getVersion() {
        throw new UnsupportedOperationException();
    }

    public boolean isStandalone() {
        throw new UnsupportedOperationException();
    }

    public boolean standaloneSet() {
        throw new UnsupportedOperationException();
    }

    public String getCharacterEncodingScheme() {
        throw new UnsupportedOperationException();
    }

    public String getPITarget() {
        throw new UnsupportedOperationException();
    }

    public String getPIData() {
        throw new UnsupportedOperationException();
    }

    public boolean isDone() {
        return (currentState == END_ELEMENT_STATE);
    }

    public void addNamespaceContext(NamespaceContext nsContext) {
        //To change body of implemented methods use File | Settings | File Templates.
    }

    public void init() {
        //To change body of implemented methods use File | Settings | File Templates.
    }
}