/*
 * 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.xerces.impl.xs.opti;

import java.util.ArrayList;
import java.util.Enumeration;

import org.apache.xerces.util.XMLSymbols;
import org.apache.xerces.xni.NamespaceContext;
import org.apache.xerces.xni.QName;
import org.apache.xerces.xni.XMLAttributes;
import org.apache.xerces.xni.XMLString;
import org.w3c.dom.Attr;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

/**
 * @xerces.internal  
 * 
 * @author Rahul Srivastava, Sun Microsystems Inc.
 * @author Sandy Gao, IBM
 *
 * @version $Id$
 */
public class SchemaDOM extends DefaultDocument {
    
    static final int relationsRowResizeFactor = 15;
    static final int relationsColResizeFactor = 10;
    
    NodeImpl[][] relations;
    // parent must be an element in this scheme
    ElementImpl parent;
    int currLoc;
    int nextFreeLoc;
    boolean hidden;
    boolean inCDATA;
    
    // for annotation support:
    private StringBuffer fAnnotationBuffer = null;
    
    public SchemaDOM() {
        reset();
    }
    
    
    public ElementImpl startElement(QName element, XMLAttributes attributes,
            int line, int column, int offset) {
        ElementImpl node = new ElementImpl(line, column, offset);
        processElement(element, attributes, node);
        // now the current node added, becomes the parent
        parent = node;
        return node;
    }
    
    public ElementImpl emptyElement(QName element, XMLAttributes attributes,
            int line, int column, int offset) {
        ElementImpl node = new ElementImpl(line, column, offset);
        processElement(element, attributes, node);
        return node;
    }
    
    public ElementImpl startElement(QName element, XMLAttributes attributes,
            int line, int column) {
        return startElement(element, attributes, line, column, -1);
    }
    
    public ElementImpl emptyElement(QName element, XMLAttributes attributes,
            int line, int column) {
        return emptyElement(element, attributes, line, column, -1);
    }
    
    private void processElement(QName element, XMLAttributes attributes, ElementImpl node) {
        
        // populate node
        node.prefix = element.prefix;
        node.localpart = element.localpart;
        node.rawname = element.rawname;
        node.uri = element.uri;
        node.schemaDOM = this;
        
        // set the attributes
        Attr[] attrs = new Attr[attributes.getLength()];
        for (int i=0; i<attributes.getLength(); i++) {
            attrs[i] = new AttrImpl(node, 
                    attributes.getPrefix(i), 
                    attributes.getLocalName(i), 
                    attributes.getQName(i), 
                    attributes.getURI(i), 
                    attributes.getValue(i));
        }
        node.attrs = attrs;
        
        // check if array needs to be resized
        if (nextFreeLoc == relations.length) {
            resizeRelations();
        }
        
        // store the current parent
        //if (relations[currLoc][0] == null || relations[currLoc][0] != parent) {
        if (relations[currLoc][0] != parent) {
            relations[nextFreeLoc][0] = parent;
            currLoc = nextFreeLoc++;
        }
        
        // add the current node as child of parent
        boolean foundPlace = false;
        int i = 1;
        for (i = 1; i<relations[currLoc].length; i++) {
            if (relations[currLoc][i] == null) {
                foundPlace = true;
                break;
            }
        }
        
        if (!foundPlace) {
            resizeRelations(currLoc);
        }
        relations[currLoc][i] = node;
        
        parent.parentRow = currLoc;
        node.row = currLoc;
        node.col = i;
    }
    
    
    public void endElement()  {
        // the parent of current parent node becomes the parent
        // for the next node.
        currLoc = parent.row;
        parent = (ElementImpl)relations[currLoc][0];
    }
    
    // note that this will only be called within appinfo/documentation
    void comment(XMLString text) {
        fAnnotationBuffer.append("<!--");
        if (text.length > 0) {
            fAnnotationBuffer.append(text.ch, text.offset, text.length);
        }
        fAnnotationBuffer.append("-->");
    }
    
    // note that this will only be called within appinfo/documentation
    void processingInstruction(String target, XMLString data) {
        fAnnotationBuffer.append("<?").append(target);
        if (data.length > 0) {
            fAnnotationBuffer.append(' ').append(data.ch, data.offset, data.length);
        }
        fAnnotationBuffer.append("?>");
    }
    
    // note that this will only be called within appinfo/documentation
    void characters(XMLString text) {
        
        // escape characters if necessary
        if (!inCDATA) {
            final StringBuffer annotationBuffer = fAnnotationBuffer;
            for (int i = text.offset; i < text.offset+text.length; ++i) {
                char ch = text.ch[i];
                if (ch == '&') {
                    annotationBuffer.append("&amp;");
                } 
                else if (ch == '<') {
                    annotationBuffer.append("&lt;");
                }
                // character sequence "]]>" cannot appear in content, 
                // therefore we should escape '>'.
                else if (ch == '>') {
                    annotationBuffer.append("&gt;");
                }
                // If CR is part of the document's content, it
                // must not be printed as a literal otherwise
                // it would be normalized to LF when the document
                // is reparsed.
                else if (ch == '\r') {
                    annotationBuffer.append("&#xD;");
                }
                else {
                    annotationBuffer.append(ch);
                }
            }
        }
        else {
            fAnnotationBuffer.append(text.ch, text.offset, text.length);
        }
    }
    
    // note that this will only be called within appinfo/documentation
    void charactersRaw(String text) {
        fAnnotationBuffer.append(text);
    }
    
    void endAnnotation(QName elemName, ElementImpl annotation) {
        fAnnotationBuffer.append("\n</").append(elemName.rawname).append(">");
        annotation.fAnnotation = fAnnotationBuffer.toString();
        // apparently, there is no sensible way of resetting these things
        fAnnotationBuffer = null;
    }
    
    void endAnnotationElement(QName elemName) {
        endAnnotationElement(elemName.rawname);
    }
    
    void endAnnotationElement(String elemRawName) {
        fAnnotationBuffer.append("</").append(elemRawName).append(">");
    }
    
    void endSyntheticAnnotationElement(QName elemName, boolean complete) {
        endSyntheticAnnotationElement(elemName.rawname, complete);
    }
    
    void endSyntheticAnnotationElement(String elemRawName, boolean complete) {
        if(complete) {
            fAnnotationBuffer.append("\n</").append(elemRawName).append(">");
            // note that this is always called after endElement on <annotation>'s
            // child and before endElement on annotation.
            // hence, we must make this the child of the current
            // parent's only child.
            parent.fSyntheticAnnotation = fAnnotationBuffer.toString();
            
            // apparently, there is no sensible way of resetting
            // these things
            fAnnotationBuffer = null;
        } else      //capturing character calls
            fAnnotationBuffer.append("</").append(elemRawName).append(">");
    }
    
    void startAnnotationCDATA() {
        inCDATA = true;
        fAnnotationBuffer.append("<![CDATA[");
    }
    
    void endAnnotationCDATA() {
        fAnnotationBuffer.append("]]>");
        inCDATA = false;
    }
    
    private void resizeRelations() {
        NodeImpl[][] temp = new NodeImpl[relations.length+relationsRowResizeFactor][];
        System.arraycopy(relations, 0, temp, 0, relations.length);
        for (int i = relations.length ; i < temp.length ; i++) {
            temp[i] = new NodeImpl[relationsColResizeFactor];
        }
        relations = temp;
    }
    
    private void resizeRelations(int i) {
        NodeImpl[] temp = new NodeImpl[relations[i].length+relationsColResizeFactor];
        System.arraycopy(relations[i], 0, temp, 0, relations[i].length);
        relations[i] = temp;
    }
    
    
    public void reset() {
        
        // help out the garbage collector
        if(relations != null) 
            for(int i=0; i<relations.length; i++) 
                for(int j=0; j<relations[i].length; j++) 
                    relations[i][j] = null;
        relations = new NodeImpl[relationsRowResizeFactor][];
        parent = new ElementImpl(0, 0, 0);
        parent.rawname = "DOCUMENT_NODE";
        currLoc = 0;
        nextFreeLoc = 1;
        inCDATA = false;
        for (int i=0; i<relationsRowResizeFactor; i++) {
            relations[i] = new NodeImpl[relationsColResizeFactor];
        }
        relations[currLoc][0] = parent;
    }
    
    
    public void printDOM() {
        /*
         for (int i=0; i<relations.length; i++) {
         if (relations[i][0] != null) {
         for (int j=0; j<relations[i].length; j++) {
         if (relations[i][j] != null) {
         System.out.print(relations[i][j].nodeType+"-"+relations[i][j].parentRow+"  ");
         }
         }
         System.out.println("");
         }
         }
         */
        //traverse(getDocumentElement(), 0);
    }
    
    
    // debug methods
    
    public static void traverse(Node node, int depth) {
        indent(depth);
        System.out.print("<"+node.getNodeName());
        
        if (node.hasAttributes()) {
            NamedNodeMap attrs = node.getAttributes();
            for (int i=0; i<attrs.getLength(); i++) {
                System.out.print("  "+((Attr)attrs.item(i)).getName()+"=\""+((Attr)attrs.item(i)).getValue()+"\"");
            }
        }
        
        if (node.hasChildNodes()) {
            System.out.println(">");
            depth+=4;
            for (Node child = node.getFirstChild(); child != null; child = child.getNextSibling()) {
                traverse(child, depth);
            }
            depth-=4;
            indent(depth);
            System.out.println("</"+node.getNodeName()+">");
        }
        else {
            System.out.println("/>");
        }
    }
    
    public static void indent(int amount) {
        for (int i = 0; i < amount; i++) {
            System.out.print(' ');
        }
    }
    
    // org.w3c.dom methods
    public Element getDocumentElement() {
        // this returns a parent node, known to be an ElementImpl
        return (ElementImpl)relations[0][1];
    }
    
    public DOMImplementation getImplementation() {
        return SchemaDOMImplementation.getDOMImplementation();
    }
    
    // commence the serialization of an annotation
    void startAnnotation(QName elemName, XMLAttributes attributes,
            NamespaceContext namespaceContext) {
        startAnnotation(elemName.rawname, attributes, namespaceContext);
    }
    void startAnnotation(String elemRawName, XMLAttributes attributes,
            NamespaceContext namespaceContext) {
        if(fAnnotationBuffer == null) fAnnotationBuffer = new StringBuffer(256);
        fAnnotationBuffer.append("<").append(elemRawName).append(" ");
        
        // attributes are a bit of a pain.  To get this right, we have to keep track
        // of the namespaces we've seen declared, then examine the namespace context
        // for other namespaces so that we can also include them.
        // optimized for simplicity and the case that not many
        // namespaces are declared on this annotation...
        ArrayList namespaces = new ArrayList();
        for (int i = 0; i < attributes.getLength(); ++i) {
            String aValue = attributes.getValue(i);
            String aPrefix = attributes.getPrefix(i);
            String aQName = attributes.getQName(i);
            // if it's xmlns:* or xmlns, must be a namespace decl
            if (aPrefix == XMLSymbols.PREFIX_XMLNS || aQName == XMLSymbols.PREFIX_XMLNS) {
                namespaces.add(aPrefix == XMLSymbols.PREFIX_XMLNS ? 
                        attributes.getLocalName(i) : XMLSymbols.EMPTY_STRING);
            }
            fAnnotationBuffer.append(aQName).append("=\"").append(processAttValue(aValue)).append("\" ");
        }
        // now we have to look through currently in-scope namespaces to see what
        // wasn't declared here
        Enumeration currPrefixes = namespaceContext.getAllPrefixes();
        while(currPrefixes.hasMoreElements()) {
            String prefix = (String)currPrefixes.nextElement();
            String uri = namespaceContext.getURI(prefix);
            if (uri == null) {
                uri = XMLSymbols.EMPTY_STRING;
            }
            if (!namespaces.contains(prefix)) {
                // have to declare this one
                if(prefix == XMLSymbols.EMPTY_STRING) {
                    fAnnotationBuffer.append("xmlns").append("=\"").append(processAttValue(uri)).append("\" ");
                }
                else {
                    fAnnotationBuffer.append("xmlns:").append(prefix).append("=\"").append(processAttValue(uri)).append("\" ");
                }
            }
        }
        fAnnotationBuffer.append(">\n");
    }
    void startAnnotationElement(QName elemName, XMLAttributes attributes) {
        startAnnotationElement(elemName.rawname, attributes);
    }
    void startAnnotationElement(String elemRawName, XMLAttributes attributes) {
        fAnnotationBuffer.append("<").append(elemRawName);
        for(int i=0; i<attributes.getLength(); i++) {
            String aValue = attributes.getValue(i);
            fAnnotationBuffer.append(" ").append(attributes.getQName(i)).append("=\"").append(processAttValue(aValue)).append("\"");
        }
        fAnnotationBuffer.append(">");
    }
    
    private static String processAttValue(String original) {
        final int length = original.length();
        // normally, nothing will happen
        for (int i = 0; i < length; ++i) {
            char currChar = original.charAt(i);
            if (currChar == '"' || currChar == '<' || currChar == '&' ||
                    currChar == 0x09 || currChar == 0x0A || currChar == 0x0D) {
                return escapeAttValue(original, i);
            }
        }
        return original;
    }
    
    private static String escapeAttValue(String original, int from) {
        int i;
        final int length = original.length();
        StringBuffer newVal = new StringBuffer(length);
        newVal.append(original.substring(0, from));
        for (i = from; i < length; ++i) {
            char currChar = original.charAt(i);
            if (currChar == '"') {
                newVal.append("&quot;");
            } 
            else if (currChar == '<') {
                newVal.append("&lt;");
            }
            else if (currChar == '&') {
                newVal.append("&amp;");
            }
            // Must escape 0x09, 0x0A and 0x0D if they appear in attribute
            // value so that they may be round-tripped. They would otherwise
            // be transformed to a 0x20 during attribute value normalization.
            else if (currChar == 0x09) {
                newVal.append("&#x9;");
            }
            else if (currChar == 0x0A) {
                newVal.append("&#xA;");
            }
            else if (currChar == 0x0D) {
                newVal.append("&#xD;");
            }
            else {
                newVal.append(currChar);
            }
        }
        return newVal.toString();
    }
}
