/*
 *  Copyright 1999-2004 The Apache Software Foundation
 *
 *  Licensed 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.jasper.compiler;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.URL;
import java.util.Hashtable;
import java.util.Vector;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import javax.servlet.jsp.tagext.TagAttributeInfo;
import javax.servlet.jsp.tagext.TagExtraInfo;
import javax.servlet.jsp.tagext.TagInfo;
import javax.servlet.jsp.tagext.TagLibraryInfo;

import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.tomcat.util.log.Log;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

/**
 * Implementation of the TagLibraryInfo class from the JSP spec. 
 *
 * @author Anil K. Vijendran
 * @author Mandar Raje
 */
public class TagLibraryInfoImpl extends TagLibraryInfo {
    static private final String TLD = "META-INF/taglib.tld";
    static private final String WEBAPP_INF = "/WEB-INF/web.xml";

    Document tld;

    Hashtable jarEntries;

    JspCompilationContext ctxt;

    

    private final void print(String name, String value, PrintWriter w) {
        if (value != null) {
            w.print(name+" = {\n\t");
            w.print(value);
            w.print("\n}\n");
        }
    }

    public String toString() {
        StringWriter sw = new StringWriter();
        PrintWriter out = new PrintWriter(sw);
        print("tlibversion", tlibversion, out);
        print("jspversion", jspversion, out);
        print("shortname", shortname, out);
        print("urn", urn, out);
        print("info", info, out);
        print("uri", uri, out);

        for(int i = 0; i < tags.length; i++)
            out.println(tags[i].toString());
        
        return sw.toString();
    }
    
    // XXX FIXME
    // resolveRelativeUri and/or getResourceAsStream don't seem to properly
    // handle relative paths when dealing when home and getDocBase are set
    // the following is a workaround until these problems are resolved.
    private InputStream getResourceAsStream(String uri) 
        throws FileNotFoundException 
    {
        if (uri.indexOf(":") > 0) {
            // may be fully qualified (Windows) or may be a URL.  Let
            // getResourceAsStream deal with it.
            return ctxt.getResourceAsStream(uri);
        } else {
            // assume it translates to a real file, and use getRealPath
            String real = ctxt.getRealPath(uri);
            return (real == null) ? null : new FileInputStream(real);
        }
    }

    public TagLibraryInfoImpl(JspCompilationContext ctxt, String prefix, String uriIn) 
        throws IOException, JasperException
    {
        super(prefix, uriIn);

	this.ctxt = ctxt;
        ZipInputStream zin;
        InputStream in = null;
        URL url = null;
        boolean relativeURL = false;
	this.uri = uriIn;

        // Parse web.xml.
        InputStream is = getResourceAsStream(WEBAPP_INF);

        if (is != null) {
            Document webtld =
                JspUtil.parseXMLDoc(is,
                                    Constants.WEBAPP_DTD_RESOURCE,
                                    Constants.WEBAPP_DTD_PUBLIC_ID);
            NodeList nList =  webtld.getElementsByTagName("taglib");

            if (nList.getLength() != 0) {
                for(int i = 0; i < nList.getLength(); i++) {
                    String tagLoc = null;
                    boolean match = false;
                    Element e =  (Element) nList.item(i);

                    // Assume only one entry for location and uri.
                    NodeList uriList = e.getElementsByTagName("taglib-uri");
                    Element uriElem = (Element) uriList.item(0);
                    Text t = (Text) uriElem.getFirstChild();

                    if (t != null) {
                        String tmpUri = t.getData();
                        if (tmpUri != null) {
                            tmpUri = tmpUri.trim();
                            if (tmpUri.equals(uriIn)) {
                                match = true;
                                NodeList locList = e.getElementsByTagName
                                    ("taglib-location");
                                Element locElem = (Element) locList.item(0);
                                Text tl = (Text) locElem.getFirstChild();
                                if (tl != null) {
                                    tagLoc = tl.getData();
                                    if (tagLoc != null)
                                        tagLoc = tagLoc.trim();
                                }
                            }
                        }
                    }
                    if (match == true && tagLoc != null) {
                        this.uri = tagLoc;

                        // If this is a relative path, then it has to be
                        // relative to where web.xml is.

                        // I'm taking the simple way out. Since web.xml 
                        // has to be directly under WEB-INF, I'm making 
                        // an absolute URI out of it by prepending WEB-INF

                        if (!uri.startsWith("/") && isRelativeURI(uri))
                            uri = "/WEB-INF/"+uri;
                    }
                }
            }
        }

        // Try to resolve URI relative to the current JSP page
        if (!uri.startsWith("/") && isRelativeURI(uri))
            uri = ctxt.resolveRelativeUri(uri);


        if (!uri.endsWith("jar")) {
	    in = getResourceAsStream(uri);
	    
	    if (in == null)
		throw new JasperException(Constants.getString("jsp.error.tld_not_found",
							      new Object[] {uri}));
	    // Now parse the tld.
	    parseTLD(in);
	}
	    
	// FIXME Take this stuff out when taglib changes are thoroughly tested.
        // 2000.11.15 commented out the 'copy to work dir' section,
        // which I believe is what this FIXME comment referred to. (pierred)
	if (uri.endsWith("jar")) {
	    
	    if (!isRelativeURI(uri)) {
		url = new URL(uri);
		in = url.openStream();
	    } else {
		relativeURL = true;
		in = getResourceAsStream(uri);
	    }
	    
	    zin = new ZipInputStream(in);
	    this.jarEntries = new Hashtable();
	    this.ctxt = ctxt;
	    
            /* NOT COMPILED
	    // First copy this file into our work directory! 
	    {
		File jspFile = new File(ctxt.getJspFile());
                String parent = jspFile.getParent();
                String jarFileName = ctxt.getOutputDir();
                if (parent != null) {
                   jarFileName = jarFileName + File.separatorChar +
                       parent;
                }
                File jspDir = new File(jarFileName);
		jspDir.mkdirs();
	    
		if (relativeURL)
		    jarFileName = jarFileName+File.separatorChar+new File(uri).getName();
		else                    
		    jarFileName = jarFileName+File.separatorChar+
			new File(url.getFile()).getName();
	    
		Constants.message("jsp.message.copyinguri", 
	                          new Object[] { uri, jarFileName },
				  Log.DEBUG);
	    
		if (relativeURL)
		    copy(getResourceAsStream(uri),
			 jarFileName);
		else
		    copy(url.openStream(), jarFileName);
	    
	        ctxt.addJar(jarFileName);
	    }
            */ // END NOT COMPILED
	    boolean tldFound = false;
	    ZipEntry entry;
	    while ((entry = zin.getNextEntry()) != null) {
		if (entry.getName().equals(TLD)) {
		    /*******
		     * This hack is necessary because XML reads until the end 
		     * of an inputstream -- does not use available()
		     * -- and closes the inputstream when it can't
		     * read no more.
		     */
		    
		    // BEGIN HACK
		    ByteArrayOutputStream baos = new ByteArrayOutputStream();
		    int b;
		    while (zin.available() != 0) {
			b = zin.read();
			if (b == -1)
			    break;
			baos.write(b);
		    }

		    baos.close();
		    ByteArrayInputStream bais 
			= new ByteArrayInputStream(baos.toByteArray());
		    // END HACK
		    tldFound = true;
		    parseTLD(bais);
		} else {
		    ByteArrayOutputStream baos = new ByteArrayOutputStream();
		    int b;
		    while (zin.available() != 0) {
			b = zin.read();
			if (b == -1)
			    break;
			baos.write(b);
		    }
		    baos.close();
		    jarEntries.put(entry.getName(), baos.toByteArray());
		}
		zin.closeEntry();
	    }
	    
	    if (!tldFound)
		throw new JasperException(Constants.getString("jsp.error.tld_not_found",
							      new Object[] {
		    TLD
			}
							      ));
	} // Take this out (END of if(endsWith("jar")))
    }
    
    /** Returns true if the given URI is relative in this web application, false if it is an internet URI.
     */
    private boolean isRelativeURI(String uri) {
        return (uri.indexOf(':') == -1);
    }
    
        
    private void parseTLD(InputStream in) 
        throws JasperException
    {
	tld = JspUtil.parseXMLDoc(in,
				  Constants.TAGLIB_DTD_RESOURCE,
				  Constants.TAGLIB_DTD_PUBLIC_ID);
	
        Vector tagVector = new Vector();
        NodeList list = tld.getElementsByTagName("taglib");

        if (list.getLength() != 1)
            throw new JasperException(Constants.getString("jsp.error.more.than.one.taglib"));

        Element elem = (Element) list.item(0);
        list = elem.getChildNodes();

        for(int i = 0; i < list.getLength(); i++) {
	    Node tmp = list.item(i);
	    if (! (tmp instanceof Element)) continue;
            Element e = (Element) tmp;
            String tname = e.getTagName();
            if (tname.equals("tlibversion")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    this.tlibversion = t.getData().trim();
            } else if (tname.equals("jspversion")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    this.jspversion = t.getData().trim();
            } else if (tname.equals("shortname")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    this.shortname = t.getData().trim();
            } else if (tname.equals("uri")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    this.urn = t.getData().trim();
            } else if (tname.equals("info")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    this.info = t.getData().trim();
            } else if (tname.equals("tag"))
                tagVector.addElement(createTagInfo(e));
            else
                Constants.message("jsp.warning.unknown.element.in.TLD", 
                                  new Object[] {
                                      e.getTagName()
                                  },
                                  Log.WARNING
                                  );
        }

        this.tags = new TagInfo[tagVector.size()];
        tagVector.copyInto (this.tags);
    }

    private TagInfo createTagInfo(Element elem) throws JasperException {
        String name = null, tagclass = null, teiclass = null;
        String bodycontent = "JSP"; // Default body content is JSP
	String info = null;
        
        Vector attributeVector = new Vector();
        NodeList list = elem.getChildNodes();
        for(int i = 0; i < list.getLength(); i++) {
            Node tmp  =  list.item(i);
	    if (! (tmp instanceof Element)) continue;
	    Element e = (Element) tmp;
            String tname = e.getTagName();
            if (tname.equals("name")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    name = t.getData().trim();
            } else if (tname.equals("tagclass")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    tagclass = t.getData().trim();
            } else if (tname.equals("teiclass")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    teiclass = t.getData().trim();
            } else if (tname.equals("bodycontent")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    bodycontent = t.getData().trim();
            } else if (tname.equals("info")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    info = t.getData().trim();
            } else if (tname.equals("attribute"))
                attributeVector.addElement(createAttribute(e));
            else 
                Constants.message("jsp.warning.unknown.element.in.tag", 
                                  new Object[] {
                                      e.getTagName()
                                  },
                                  Log.WARNING
                                  );
        }
	TagAttributeInfo[] tagAttributeInfo 
            = new TagAttributeInfo[attributeVector.size()];
	attributeVector.copyInto (tagAttributeInfo);

        TagExtraInfo tei = null;

        if (teiclass != null && !teiclass.equals(""))
            try {
                Class teiClass = ctxt.getClassLoader().loadClass(teiclass);
                tei = (TagExtraInfo) teiClass.newInstance();
	    } catch (ClassNotFoundException cex) {
                Constants.message("jsp.warning.teiclass.is.null",
                                  new Object[] {
                                      teiclass, cex.getMessage()
                                  },
                                  Log.WARNING
                                  );
            } catch (IllegalAccessException iae) {
                Constants.message("jsp.warning.teiclass.is.null",
                                  new Object[] {
                                      teiclass, iae.getMessage()
                                  },
                                  Log.WARNING
                                  );
            } catch (InstantiationException ie) {
                Constants.message("jsp.warning.teiclass.is.null",
                                  new Object[] {
                                      teiclass, ie.getMessage()
                                  },
                                  Log.WARNING
                                  );
            }

        TagInfo taginfo = new TagInfo(name, tagclass, bodycontent,
                                      info, this, 
                                      tei,
                                      tagAttributeInfo);
        return taginfo;
    }

    TagAttributeInfo createAttribute(Element elem) {
        String name = null;
        boolean required = false, rtexprvalue = false, reqTime = false;
        String type = null;
        
        NodeList list = elem.getChildNodes();
        for(int i = 0; i < list.getLength(); i++) {
            Node tmp  = list.item(i);
	    if (! (tmp instanceof Element)) continue;
	    Element e = (Element) tmp;
            String tname = e.getTagName();
            if (tname.equals("name"))  {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    name = t.getData().trim();
            } else if (tname.equals("required"))  {
                Text t = (Text) e.getFirstChild();
                if (t != null) {
                    required = Boolean.valueOf(t.getData().trim()).booleanValue();
                    if( t.getData().equalsIgnoreCase("yes") )
                        required = true;
                }
            } else if (tname.equals("rtexprvalue")) {
                Text t = (Text) e.getFirstChild();
                if (t != null) {
                    rtexprvalue = Boolean.valueOf(t.getData().trim()).booleanValue();
                    if( t.getData().equalsIgnoreCase("yes") )
                        rtexprvalue = true;
                }
            } else if (tname.equals("type")) {
                Text t = (Text) e.getFirstChild();
                if (t != null)
                    type = t.getData().trim();
            } else 
                Constants.message("jsp.warning.unknown.element.in.attribute", 
                                  new Object[] {
                                      e.getTagName()
                                  },
                                  Log.WARNING
                                  );
        }
        
	//     return new TagAttributeInfo(name, required, rtexprvalue, type);
        return new TagAttributeInfo(name, required, type, rtexprvalue);
    }

    static void copy(InputStream in, String fileName) 
        throws IOException, FileNotFoundException 
    {
        byte[] buf = new byte[1024];

        FileOutputStream out = new FileOutputStream(fileName);
        int nRead;
        while ((nRead = in.read(buf, 0, buf.length)) != -1)
            out.write(buf, 0, nRead);
    }

}