/plugins/XML/trunk/xml/hyperlinks/XMLHyperlinkSource.java

/*

 * XMLHyperlinkSource.java - Hyperlink source from the XML plugin

 * :tabSize=8:indentSize=8:noTabs=false:

 * :folding=explicit:collapseFolds=1:

 *

 * Copyright (C) 2011 Eric Le Lay

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or any later version.

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 */

package xml.hyperlinks;



import java.io.Reader;

import java.net.URI;

import java.util.Arrays;

import java.util.regex.Pattern;

import java.util.regex.Matcher;



import org.gjt.sp.jedit.View;

import org.gjt.sp.jedit.jEdit;

import org.gjt.sp.jedit.Buffer;

import org.gjt.sp.util.Log;



import sidekick.SideKickParsedData;

import sidekick.IAsset;

import sidekick.util.ElementUtil;



import gatchan.jedit.hyperlinks.*;



import static xml.Debug.*;

import xml.Resolver;

import xml.CharSequenceReader;

import xml.XmlParsedData;

import xml.parser.javacc.*;

import xml.parser.XmlTag;

import xml.completion.ElementDecl;

import xml.completion.IDDecl;



/**

 * Provides hyperlinks from XML attributes.

 * Supported hyperlinks are :

 * <ul>

 * 	<li>XInclude (&lt;xi:include href="..."/&gt;). Fragments are not supported:

 *	      the buffer is opened and that's all.

 *	</li>

 *	<li>simple XLinks (&lt;myelt xlink:href="..."/&gt;). Only simple links are supported:

 *	      the buffer is opened and that's all.

 *	</li>

 *	<li>IDREF attributes, when the buffer has been parsed and the attribute has the

 *	      IDREF datatype. This includes docbook 4.x links (&lt;xref linkend="id"/&gt;).

 *	</li>

 *	<li>XML Schema (XSD) schema location (&lt;myelt xsi:schemaLocation="ns1 url1..."&gt;)

 *	      and no namespace schema location (&lt;myelt xsi:noNamespaceSchemaLocation="url"&gt;).

 *	</li>

 *	<li>attributes with datatype anyURI

 *	      eg. XSD include and import (&lt;xs:include schemaLocation="url"/&gt;).

 *	</li>

 *	<li>DocBook ulink (&lt;ulink url="..."&gt;)</li>

 * </ul>

 *

 * @todo	HTML attributes

 * @todo	HTML BASE tag (beware: it's in HTML/HEAD)

 *

 * @author Eric Le Lay

 * @version $Id: XMLHyperlinkSource.java 21198 2012-02-24 11:19:21Z kerik-sf $

 */

public class XMLHyperlinkSource implements HyperlinkSource

{

	/**

	 * Returns the hyperlink for the given offset.

	 * returns an hyperlink as soon as pointer enters the attribute's value

	 *

	 * @param buffer the buffer

	 * @param offset the offset

	 * @return the hyperlink (or null if there is no hyperlink)

	 */

	public Hyperlink getHyperlink(Buffer buffer, int offset){

		View view = jEdit.getActiveView();

		XmlParsedData data = XmlParsedData.getParsedData(view, false);

		if(data==null)return null;

		

		IAsset asset = data.getAssetAtOffset(offset);

		if(asset == null){

			Log.log(Log.DEBUG, XMLHyperlinkSource.class,"no Sidekick asset here");

			return null;

		} else {

			int wantedLine = buffer.getLineOfOffset(offset);

			int wantedLineOffset = buffer.getVirtualWidth(wantedLine, offset - buffer.getLineStartOffset(wantedLine));





			/* use the XML javacc parser to parse the start tag.*/

			int max = buffer.getLength();

			int sA = asset.getStart().getOffset();

			int lA = asset.getEnd().getOffset()-sA;

			if(sA < 0 || sA > max){

				return null;

			}

			if(lA < 0 || sA+lA > max){

				return null;

			}

			CharSequence toParse = buffer.getSegment(sA,lA);

			int line = buffer.getLineOfOffset(sA);

			int col = buffer.getVirtualWidth(line, sA-buffer.getLineStartOffset(line)+1);

			Reader r = new CharSequenceReader(toParse);

			XmlParser parser = new XmlParser(r, line+1, col);

			parser.setTabSize( buffer.getTabSize() );

			try{

				XmlDocument.XmlElement startTag = parser.Tag();

				int start = ElementUtil.createStartPosition(buffer,startTag).getOffset();

				int end= ElementUtil.createEndPosition(buffer,startTag).getOffset();

				/* if the offset is inside start tag */

				if(offset <= end)

				{

					XmlDocument.AttributeList al = ((XmlDocument.Tag)startTag).attributeList;

					if(al == null){

						if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG,XMLHyperlinkSource.class,"no attribute in this element");

						return null;

					}else{

						for(XmlDocument.Attribute att: al.attributes){

							// offset is inside attribute's value

							if(  (    att.getValueStartLocation().line < wantedLine+1

							       || (att.getValueStartLocation().line == wantedLine+1

						                   && att.getValueStartLocation().column <= wantedLineOffset)

						              )

						              &&

						              (    att.getEndLocation().line > wantedLine+1

							       || (att.getEndLocation().line == wantedLine+1

						                   && att.getEndLocation().column > wantedLineOffset)

						              )

						          )

						        {

						        	if(asset instanceof XmlTag) {

						        		return getHyperlinkForAttribute(buffer, offset, data, asset, att);

						        	}

						        }

						}

						if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG,XMLHyperlinkSource.class,"not inside attributes");

						return null;

					}

				}else{

					return null;

				}

			}catch(ParseException pe){

				if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG, XMLHyperlinkSource.class, "error parsing element", pe);

				return null;

			}

		}

	}

	

	/**

	 * get an hyperlink for an identified XML attribute

	 * @param	buffer	current buffer

	 * @param	offset	offset where an hyperlink is required in current buffer

	 * @param	data		sidekick tree for current buffer

	 * @param	asset		element containing offset

	 * @param	att		parsed attribute

	 */

	public Hyperlink getHyperlinkForAttribute(

		Buffer buffer, int offset, XmlParsedData data, 

		IAsset asset, XmlDocument.Attribute att)

	{

		XmlTag sideKickTag = (XmlTag)asset;

		

		if(sideKickTag.attributes == null){

			if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG,XMLHyperlinkSource.class,"Sidekick version of this element doesn't have attributes");

			return null;

		}

		

		int attIndex = sideKickTag.attributes.getIndex(att.name);

		if(attIndex < 0){

			if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG,XMLHyperlinkSource.class,"Sidekick version of this element doesn't have this attribute: "+att.name);

			return null;

		}

		

		String tagNS = sideKickTag.namespace;

		String tagLocalName = sideKickTag.getLocalName();

		

		String ns = sideKickTag.attributes.getURI(attIndex);

		String localName = att.name.contains(":")? sideKickTag.attributes.getLocalName(attIndex) : att.name;

		String value = sideKickTag.attributes.getValue(attIndex);

		

		Hyperlink h = getHyperlinkForAttribute(buffer, offset,

			tagNS,tagLocalName, ns, localName, value,

			data, sideKickTag, att);

		

		if(h == null) {

		

			ElementDecl eltDecl  = data.getElementDecl(sideKickTag.getName(),offset);

			if(eltDecl == null){

				if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG,XMLHyperlinkSource.class,"no element declaration for "+tagLocalName);

			}else{

				ElementDecl.AttributeDecl attDecl = eltDecl.attributeHash.get(localName);

				if(attDecl == null){

					if(DEBUG_HYPERLINKS)Log.log(Log.DEBUG,XMLHyperlinkSource.class,"no attribute declaration for "+localName);

					return null;

				}else{

					if("IDREF".equals(attDecl.type)){

						return getHyperlinkForIDREF(buffer, data, value, att);

					}else if("anyURI".equals(attDecl.type)){

						// FIXME: shall it use xml:base ?

						String href =  resolve(value, buffer, offset, data, sideKickTag, false);

						if(href!=null){

							return newJEditOpenFileHyperlink(buffer, att, href);

						}

					}else if("IDREFS".equals(attDecl.type)){

						return getHyperlinkForIDREFS(buffer, offset, data, value, att);

					}

					return null;

				}

			}

			

		} else {

			return h;

		}

		return null;

	}

	

	/**

	 * creates an hyperlink to the location of the element with id (in same or another buffer).

	 * @param	buffer	current buffer

	 * @param	data		sidekick tree

	 * @param	id		id we are looking for

	 * @param	att		parsed attribute (for hyperlink boundaries)

	 */

	public Hyperlink getHyperlinkForIDREF(Buffer buffer,

		XmlParsedData data, String id, XmlDocument.Attribute att)

	{

		IDDecl idDecl = data.getIDDecl(id);

		if(idDecl == null){

			return null;

		} else{

			return newJEditOpenFileAndGotoHyperlink(buffer, att,

			idDecl.uri, idDecl.line, idDecl.column);

		}

	}

	

	// {{{ getHyperlinkForIDREFS() method

	private static final Pattern noWSPattern = Pattern.compile("[^\\s]+");

	/**

	 * creates an hyperlink to the location of the element with id (in same or another buffer)

	 * @param	buffer	current buffer

	 * @param	offset	offset of required hyperlink

	 * @param	data		sidekick tree

	 * @param	attValue		ids in the attribute

	 * @param	att		parsed attribute (for hyperlink boundaries)

	 */

	public Hyperlink getHyperlinkForIDREFS(Buffer buffer, int offset,

		XmlParsedData data, String attValue, XmlDocument.Attribute att)

	{

		int attStart = xml.ElementUtil.createOffset(buffer, att.getValueStartLocation());

		// +1 for the quote around the attribute value

		attStart++;

		

		Matcher m = noWSPattern.matcher(attValue);

		while(m.find()){

			int st = m.start(0);

			int nd = m.end(0);

			if(attStart + st <= offset && attStart + nd >= offset){

				IDDecl idDecl = data.getIDDecl(m.group(0));

				if(idDecl==null)return null;

				int start = attStart + st;

				int end= attStart + nd;

				int line = buffer.getLineOfOffset(start);

				return new jEditOpenFileAndGotoHyperlink(start, end, line, idDecl.uri, idDecl.line, idDecl.column);

			}

		}

		return null;

	}//}}}

	

	//{{{ getHyperlinkForAttribute(tagNS,tagName,attNS,attName) method

	private static final Pattern nsURIPairsPattern = Pattern.compile("[^\\s]+\\s+([^\\s]+)");

	/**

	 * recognize hyperlink attributes by their parent element's

	 * namespace:localname and/or their namespace:localname

	 */

	public Hyperlink getHyperlinkForAttribute(Buffer buffer, int offset,

		String tagNS, String tagLocalName,

		String attNS, String attLocalName, String attValue,

		XmlParsedData data, XmlTag tag, XmlDocument.Attribute att)

	{

		String href = null; 

		if("http://www.w3.org/2001/XInclude".equals(tagNS)

			&& "include".equals(tagLocalName)

			&& "href".equals(attLocalName))

		{

			href = resolve(attValue, buffer, offset, data, tag, true);

		} else if("http://www.w3.org/1999/xlink".equals(attNS)

			&& "href".equals(attLocalName))

		{

			href = resolve(attValue, buffer, offset, data, tag, true);

		} else if("http://www.w3.org/2001/XMLSchema-instance".equals(attNS)

			&& "noNamespaceSchemaLocation".equals(attLocalName))

		{

			href = resolve(attValue, buffer, offset, data, tag, false);

		} else if("".equals(tagNS) && "ulink".equals(tagLocalName)

				&& "url".equals(attLocalName))

		{

			href = resolve(attValue, buffer, offset, data, tag, false);

		} else if("http://www.w3.org/2001/XMLSchema-instance".equals(attNS)

			&& "schemaLocation".equals(attLocalName))

		{

			

			// +1 for the quote around the attribute value

			int attStart = xml.ElementUtil.createOffset(buffer, att.getValueStartLocation()) +1;

			

			Matcher m = nsURIPairsPattern.matcher(attValue);

			// find will accept unbalanced pairs of ns->uri

			while(m.find()){

				int st = m.start(1);

				int nd = m.end(1);

				if(attStart + st <= offset && attStart + nd >= offset){

					href = resolve(m.group(1), buffer, offset, data, tag, false);

					if(href==null)href=m.group(1);

					int start = attStart + st;

					int end= attStart + nd;

					int line = buffer.getLineOfOffset(start);

					return new jEditOpenFileHyperlink(start, end, line, href);

				}

			}

		}

		if(href==null){

			return null;

		}else{

			return newJEditOpenFileHyperlink(

				buffer, att, href);

		}

	}//}}}

	

	/**

	 * resolve a potentially relative uri using xml:base attributes,

	 * the buffer's URL, xml.Resolver.

	 * Has the effect of opening the cached document if it's in cache (eg. docbook XSD if not in catalog).

	 * Maybe this is not desirable, because if there is a relative link in this document, it won't work

	 * because the document will be .jedit/dtds/cachexxxxx.xml and not the real url.

	 *

	 * @param	uri		text of uri to reach

	 * @param	buffer	current buffer

	 * @param	offset	offset in current buffer where an hyperlink is required

	 * @param	data		SideKick parsed data

	 * @param	tag		SideKick asset

	 * @param	useXmlBase	should xml:base attribute be used to resolve uri (only for XML!)

	 *

	 * @return	resolved URL

	 */

	public String resolve(String uri, Buffer buffer, int offset, XmlParsedData data, XmlTag tag,

		boolean useXmlBase)

	{

		String href = null;

		String base = xml.PathUtilities.pathToURL(buffer.getPath());

		if(useXmlBase){

			try {

				URI baseURI = URI.create(base);

				Object[] pathObjs = data.getObjectsTo(offset);

				// go down the tree, resolving existing xml:base uri if they exist

				for(int i=1; i<pathObjs.length;i++){  //first object (i==0) is a SourceAsset for the file

					XmlTag t = (XmlTag)pathObjs[i];

					String newBase = t.attributes.getValue("xml:base"); // xml is a reserved prefix

					if(newBase!=null){

						baseURI = baseURI.resolve(newBase);

					}

				}

				if(!base.equals(baseURI.toString())){

					// add a dummy component, otherwise xml.Resolver

					// removes the last part of the xml:base

					// FIXME: review xml.Resolver : it should only be used with URLs

					// for current, now, so could use URI.resolve() instead of removing

					// last part of the path to get the parent...

					baseURI = baseURI.resolve("dummy");

					base = baseURI.toString();

				}

			}catch(IllegalArgumentException e){

				Log.log(Log.WARNING, XMLHyperlinkSource.class, "error resolving uri", e);

			}

		}

		try{

			href = Resolver.instance().resolveEntityToPath(

				"", /*name*/

				"", /*publicId*/

				base, /*current, augmented by xml:base */

				uri);

		}catch(java.io.IOException ioe){

			Log.log(Log.ERROR,XMLHyperlinkSource.class,"error resolving href="+uri,ioe);

		}

		return href;

	}

	

	/**

	 * create an hyperlink for attribute att.

	 * the hyperlink will span whole attribute value

	 * @param	buffer	current buffer

	 * @param	att		parsed attribute

	 * @param	href		uri to open

	 */

	public Hyperlink newJEditOpenFileHyperlink(

		Buffer buffer, XmlDocument.Attribute att, String href)

	{

		int start = xml.ElementUtil.createOffset(buffer,att.getValueStartLocation());

		int end= xml.ElementUtil.createOffset(buffer,att.getEndLocation());

        	int line = buffer.getLineOfOffset(start);

        	return new jEditOpenFileHyperlink(start, end, line, href);

	}



	/**

	 * create an hyperlink for attribute att.

	 * the hyperlink will span whole attribute value

	 * @param	buffer	current buffer

	 * @param	att		parsed attribute

	 * @param	href		uri to open

	 * @param	gotoLine	target line in buffer

	 * @param	gotoCol	target column in buffer

	 */

	public Hyperlink newJEditOpenFileAndGotoHyperlink(

		Buffer buffer, XmlDocument.Attribute att, String href, int gotoLine, int gotoCol)

	{

		int start = xml.ElementUtil.createOffset(buffer,att.getValueStartLocation());

		int end= xml.ElementUtil.createOffset(buffer,att.getEndLocation());

        	int line = buffer.getLineOfOffset(start);

        	return new jEditOpenFileAndGotoHyperlink(start, end, line, href, gotoLine, gotoCol);

	}



	public static HyperlinkSource create(){

		return new FallbackHyperlinkSource(

			Arrays.asList(new XMLHyperlinkSource(),

				new gatchan.jedit.hyperlinks.url.URLHyperlinkSource()));

	}

}