package org.crosswire.xml;

/**
 * Copyright (c) 2001 CrossWire Bible Society. 
 * Distributable under the terms of the GNU GPL V2.
 */


import java.io.InputStream;
import java.io.OutputStream;

import org.w3c.dom.Node;


/** A basic utility for manipulating a block of XML data.
 *  This utility class can manipulate arbitrary tags, values, and subblocks
 *   of an XML block.  It is meant to be extended, with the subclass providing
 *   setters and getters for tags, values, and subblocks so as to solidify
 *   the XML scheme.
 *
 * @author Troy A. Griffitts
 * @version $Id: XMLBlock.java,v 1.24.2.9 2001/03/10 00:00:35 troy Exp $
 */

 public class XMLBlock extends XMLTag implements org.crosswire.webtools.CustomXMLDoc {



    /** A static method to construct and return an XMLBlock by asking a
     *  DOM Parser to parse a String of XML and assign this XMLBlock's root
     *  to the root of the parsed tree.
     *  @param xml the String of XML to parse.
     *  @return the created XMLBlock.
     *  @exception XMLParseException if the string is not well formed XML
     */
    public static XMLBlock getRoot(String xml) throws XMLParseException {
        return LocalXMLProvider.getRoot(xml);
    }

    /** A static method to construct and return an XMLBlock by asking a
     *  DOM Parser to parse a String of XML. This method does not explicitly
     *  throw an exception and should be used only for an XML string that is
     *  known to be well formed.
     *  @param xml the String of XML to parse and create an XMLBlock from.
     *  @return the created XMLBlock.
     */
    public static XMLBlock createXMLBlock(String xml) {
        try {
            return LocalXMLProvider.getRoot(xml);
        } catch(Exception exp) {
            throw new RuntimeException(exp.toString());
        }
    }


    public static XMLBlock loadXMLBlock(InputStream in) {
        try {
            return new XMLBlock(LocalXMLProvider.streamToNode(in));
        } catch(Exception exp) {
            throw new RuntimeException(exp.toString());
        }
    }


    public void save(OutputStream out) {
        try {
            LocalXMLProvider.nodeToStream(getNode(), out);
        } catch(Exception exp) {
            throw new RuntimeException(exp.toString());
        }
    }


    public XMLBlock(XMLProvider p, XMLResolver r) {
        super(p, r);
    }

    /** Construct an XMLBlock with a W3C Node object as it's root.
     *  @param root the W3C Node object to designate as this block's 'root'.
     */

    public XMLBlock(Node root) {
        super(root);
    }


    /** Construct an XMLBlock obtaining its identity from another XMLBlock or
     *  subclass.  The new object will read and modify the same data as the
     *  object passed to it.
     *  @param other the other object from which to grab identity.
     */

    public XMLBlock(XMLTag other) {
        super(other);
    }


    /** Construct an XMLBlock by asking a DOM Parser to parse a String of XML
     *  and assign this XMLBlock's root to the root of the parsed tree.
     *  @param xml the String of XML to parse.
     *  @exception XMLParseException if the string is not well formed XML
     */
    public XMLBlock(String xml) throws XMLParseException {
        this(XMLBlock.getRoot(xml));
    }


    /** Gets a value from a tag block (eg. <TAG>VALUE</TAG>) that is a child
     *  of this XMLBlock.
     *  @param key the tag name to find and for which to retrieve the value.
     *  @return VALUE text for the tag.
     */

    public String getValue(String key) {
        return provider.getValue(key);

    }


    /** Sets a value for a tag block (eg. <TAG>VALUE</TAG>) that is a child
     *  of this XMLBlock.  The tag block will be created if it does not exist.
     *  @param key the tag name to find/create and for which to set the value.
     *  @param value the value text to set for the tag block.
     *  @return the XMLDataElement that was set/created.
     */

    public XMLDataElement setValue(String key, String value) {
        return resolver.setValue(key, value);
    }


    /** Creates and sets a value for a tag block (eg. <TAG>VALUE</TAG>) as a
     *  child of this XMLBlock.  The tag block will be created regardless if
     *  another tag block with the same key value already exists.
     *  @param key the tag name to create and for which to set the value.
     *  @param value the value text to set for the tag block.
     *  @return the XMLDataElement that was created.
     */

    public XMLDataElement createValue(String key, String value) {
        return resolver.createValue(key, value);
    }


    public XMLDataElement getElement(String key) {
        return provider.getElement(key);
    }

    /** Gets all <TAG>VALUE</TAG> type elements that are immediate children
     *  of this XMLBlock.
     *  @return array of XMLDataElement objects.
     */

    public XMLDataElement [] getElements() {
        return provider.getElements();
    }


    /** Gets all <TAG>VALUE</TAG> type elements that are immediate children
     *  of this XMLBlock.
     *  @return array of XMLDataElement objects.
     */

    public XMLDataElement [] getElements(String key) {
        return provider.getElements(key);
    }


    /** Copies an XMLBlock to this document as a child of this XMLBlock.
     *  @param newBlk the block to import.
     *  @return the new XMLBlock child of this XMLBlock.
     */

    public XMLBlock addBlock(XMLBlock newBlk) {
        return resolver.addBlock(newBlk);
    }


    /** Creates a new block as a child of this XMLBlock.  The block will be
     *  created regardless if another block with the same key value already
     *  exists.
     *  @param key the tag name to give the newly created block.
     *  @return the XMLBlock that was created.
     */

    public XMLBlock createBlock(String key) {
        return resolver.createBlock(key);
    }


    /** Removes a child from this XMLBlock.  All XMLObjects extend from XMLTag,
     *  so sending any XMLObject previously retrieved from this block will
     *  remove it from this block.
     *  @param tag any XMLObject that is a child of this XMLBlock.
     */

    public void removeChild(XMLTag tag) {
        resolver.removeChild(tag);
    }


    /** Gets all the children of this XMLBlock.
     *  @return array of XMLTag objects.
     */

    public XMLTag [] getChildren() {
        return provider.getChildren();
    }

    /** Gets all block type elements that are immediate children of this
     *  XMLBlock.
     *  @return array of XMLBlock objects.
     */

    public XMLBlock [] getBlocks() {
        return provider.getBlocks();
    }


    /** Gets all block type elements that are immediate children of this
     *  XMLBlock and that have a specified tag name.
     *  @param key the tag name for which to find corresponding child XMLBlock
     *  objects.
     *  @return array of XMLBlock objects.
     */

    public XMLBlock [] getBlocks(String key) {
        return provider.getBlocks(key);
    }
    public XMLBlock [] getBlocks(String key, Class clas) {
        return provider.getBlocks(key, clas);
    }


    /** Gets all block type elements that are immediate children of this
     *  XMLBlock and that have a specified tag name and attribute value pair.
     *  @param key the tag name for which to find corresponding child XMLBlock
     *  objects.
     *  @param attr1 the attribute on which to filter.
     *  @param att1Val the attribute value for which to filter.
     *  @return array of XMLBlock objects.
     */

    public XMLBlock [] getBlocks(String key, String attr1, String att1Val) {
        return provider.getBlocks(key, attr1, att1Val);
    }

    public XMLBlock [] getBlocks(String key, String attr1, String att1Val, Class clas) {
        return provider.getBlocks(key, attr1, att1Val, clas);
    }


    /** Gets all block type elements that are immediate children of this
     *  XMLBlock and that have a specified tag name and 2 attribute value pairs.
     *  @param key the tag name for which to find corresponding child XMLBlock
     *  objects.
     *  @param attr1 the first attribute on which to filter.
     *  @param att1Val the first attribute value for which to filter.
     *  @param attr2 the second attribute on which to filter.
     *  @param att2Val the second attribute value for which to filter.
     *  @return array of XMLBlock objects.
     */

    public XMLBlock [] getBlocks(String key, String attr1, String att1Val,
                            String attr2, String att2Val) {
        return provider.getBlocks(key, attr1, att1Val, attr2, att2Val);
    }

    public XMLBlock [] getBlocks(String key, String attr1, String att1Val,
                            String attr2, String att2Val, Class clas) {
        return provider.getBlocks(key, attr1, att1Val, attr2, att2Val, clas);
    }

    /** Gets the first block type element that is an immediate child of this
     *  XMLBlock and that has a specified tag name.
     *  @param key the tag name for which to find corresponding child XMLBlock
     *  objects.
     *  @return the first XMLBlock that meets the criteria, otherwise null.
     */

    public XMLBlock getBlock(String key) {
        return provider.getBlock(key);
    }


    /** Gets the first block type element that is an immediate child of this
     *  XMLBlock and that has a specified tag name and attribute value pair.
     *  @param key the tag name for which to find corresponding child XMLBlock
     *  objects.
     *  @param attr1 the attribute on which to filter.
     *  @param att1Val the attribute value for which to filter.
     *  @return the first XMLBlock that meets the criteria, otherwise null.
     */

    public XMLBlock getBlock(String key, String attr1, String att1Val) {
        return provider.getBlock(key, attr1, att1Val);
    }


    /** Gets the first block type element that is an immediate child of this
     *  XMLBlock and that has a specified tag name and 2 attribute value pairs.
     *  @param key the tag name for which to find corresponding child XMLBlock
     *  objects.
     *  @param attr1 the first attribute on which to filter.
     *  @param att1Val the first attribute value for which to filter.
     *  @param attr2 the second attribute on which to filter.
     *  @param att2Val the second attribute value for which to filter.
     *  @return array of XMLBlock objects
     */
    public XMLBlock getBlock(String key, String attr1, String att1Val,
                            String attr2, String att2Val) {
        return provider.getBlock(key, attr1, att1Val, attr2, att2Val);
    }


     /** Filters an array of XMLBlocks by an attribute, value pair
      *  @param attr the attribute on which to filter.
      *  @param attVal the attribute value for which to filter.
      *  @return the new XMLBlock array filtered by the attribute, value pair.
      */

    public XMLBlock [] filterBlocks(XMLBlock[]superset, String attr, String attVal) {
        return provider.filterBlocks(superset, attr, attVal);
    }


     /** Retrieves the String representation of this XMLBlock and children.
      *  @return the String representation of this XMLBlock and children.
      */

    public String toString() {
        return provider.toString();
    }


	public String toXML(int detailLevel) {
		return toString();
	}

    public String formattedString() {
        // cool way

        StringBuffer retVal = new StringBuffer(super.toString()+"\n");
        XMLBlock [] blocks = getBlocks();
        for (int i = 0; i < blocks.length; i++)
            retVal.append(blocks[i].formattedString());

        XMLDataElement [] elements = getElements();
        for (int i = 0; i < elements.length; i++)
            retVal.append(elements[i].toString());

        retVal.append("</"+getName()+">\n");
        return retVal.toString();
    }

            /** A utility function for subclasses to provide common 'property'.
        *  functionality for an XMLBlock XMLDataElement.
        *
        * <br>
        * <br>
        *  eg.
        * <code>
        *  String getSKU() { return stdProp("SKU"); }
        * </code>
        * <br>
        *
        *  @param key the key name of the property.
        *  @return the value of the property.
        */

        protected String stdProp(String key) {
            String val = getValue(key);

        /* don't assign default "" values

            if (val == null) {
                createValue(key, "");
                val = "";
            }

        */
            return val;
        }

            /** A utility function for subclasses to provide common 'property'
        *  functionality for an XMLBlock XMLDataElement.
        *
        * <br>
        * <br>
        *  eg.
        * <code>
        *  void setSKU(String value) { stdProp("SKU", value); }
        * </code>
        * <br>
        *
        *  @param key the key name of the property.
        *  @param value the value to which to set the property.
        */

        protected void stdProp(String key, String value) {
            setValue(key, value);
        }
        
        public static void main(String[] args) {
            String modListURL = "http://www.crosswire.org/study/examples/booklistxml.jsp";
            StringBuffer result = org.crosswire.utils.HTTPUtils.postURL(modListURL, null);
            XMLBlock modules = XMLBlock.createXMLBlock(result.toString());
       //   for (XMLBlock module : modules.getBlocks("module", "category", "Biblical Texts")) {
            System.out.println("Count: "+modules.getBlocks("module").length);
            for (XMLDataElement module : modules.getElements("module")) {
       System.out.println("<EnumValue value=" + module.getAttribute("id")+" display_value="+ module.getText());
            }
        }
    }