/*******************************************************************************
 * Copyright (c) 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.jsp.ui.internal.contentassist;


import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jst.jsp.core.internal.provisional.JSP11Namespace;
import org.eclipse.jst.jsp.core.taglib.IJarRecord;
import org.eclipse.jst.jsp.core.taglib.ITLDRecord;
import org.eclipse.jst.jsp.core.taglib.ITaglibDescriptor;
import org.eclipse.jst.jsp.core.taglib.ITaglibRecord;
import org.eclipse.jst.jsp.core.taglib.IURLRecord;
import org.eclipse.jst.jsp.core.taglib.TaglibIndex;
import org.eclipse.jst.jsp.ui.internal.JSPUIPlugin;
import org.eclipse.wst.common.uriresolver.internal.util.URIHelper;
import org.eclipse.wst.sse.core.StructuredModelManager;
import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegionContainer;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegionList;
import org.eclipse.wst.sse.core.utils.StringUtils;
import org.eclipse.wst.sse.ui.internal.contentassist.CustomCompletionProposal;
import org.eclipse.wst.sse.ui.internal.contentassist.IRelevanceConstants;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;
import org.eclipse.wst.xml.ui.internal.contentassist.ContentAssistRequest;
import org.w3c.dom.Node;

/**
 * @plannedfor 1.0
 */
public class JSPTaglibDirectiveContentAssistProcessor extends JSPDummyContentAssistProcessor {

	public JSPTaglibDirectiveContentAssistProcessor() {
		super();
	}

	String getSmallImageURL(ITaglibRecord taglibRecord) {
		String url = null;
		switch (taglibRecord.getRecordType()) {
			case (ITaglibRecord.TLD) : {
				ITLDRecord record = (ITLDRecord) taglibRecord;
				IResource file = ResourcesPlugin.getWorkspace().getRoot().getFile(record.getPath());
				if (file.getLocation() != null && record.getDescriptor().getSmallIcon().length() > 0) {
					url = "file:" + URIHelper.normalize(record.getDescriptor().getSmallIcon(), file.getFullPath().toString(), TaglibIndex.getContextRoot(file.getFullPath()).toString()); //$NON-NLS-1$
				}
			}
				break;
			case (ITaglibRecord.JAR) : {
				IJarRecord record = (IJarRecord) taglibRecord;
				if (record.getDescriptor().getSmallIcon().length() > 0) {
					// url = "file:" +
					// URIHelper.normalize(record.getDescriptor().getSmallIcon(),
					// record.getLocation().toString(), "/"); //$NON-NLS-1$
				}
			}
				break;
			case (ITaglibRecord.TAGDIR) : {
			}
				break;
			case (ITaglibRecord.URL) : {
				IURLRecord record = (IURLRecord) taglibRecord;
				if (record.getDescriptor().getSmallIcon().length() > 0) {
					url = URIHelper.normalize(record.getDescriptor().getSmallIcon(), record.getURL().toString(), "/"); //$NON-NLS-1$
				}
			}
				break;
		}
		return url;
	}


	protected void addAttributeValueProposals(ContentAssistRequest contentAssistRequest) {
		IPath basePath = getBasePath(contentAssistRequest);
		if (basePath == null)
			return;

		IDOMNode node = (IDOMNode) contentAssistRequest.getNode();

		// Find the attribute name for which this position should have a value
		IStructuredDocumentRegion open = node.getFirstStructuredDocumentRegion();
		ITextRegionList openRegions = open.getRegions();
		int i = openRegions.indexOf(contentAssistRequest.getRegion());
		if (i < 0)
			return;
		ITextRegion nameRegion = null;
		while (i >= 0) {
			nameRegion = openRegions.get(i--);
			if (nameRegion.getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_NAME)
				break;
		}

		String attributeName = null;
		if (nameRegion != null)
			attributeName = open.getText(nameRegion);

		String currentValue = null;
		if (contentAssistRequest.getRegion().getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_VALUE)
			currentValue = contentAssistRequest.getText();
		else
			currentValue = ""; //$NON-NLS-1$
		String matchString = null;
		// fixups
		int start = contentAssistRequest.getReplacementBeginPosition();
		int length = contentAssistRequest.getReplacementLength();
		if (currentValue.length() > StringUtils.strip(currentValue).length() && (currentValue.startsWith("\"") || currentValue.startsWith("'")) //$NON-NLS-1$ //$NON-NLS-2$
					&& contentAssistRequest.getMatchString().length() > 0) {
			matchString = currentValue.substring(1, contentAssistRequest.getMatchString().length());
		}
		else
			matchString = currentValue.substring(0, contentAssistRequest.getMatchString().length());
		boolean existingComplicatedValue = contentAssistRequest.getRegion() != null && contentAssistRequest.getRegion() instanceof ITextRegionContainer;
		if (existingComplicatedValue) {
			contentAssistRequest.getProposals().clear();
			contentAssistRequest.getMacros().clear();
		}
		else {
			String lowerCaseMatch = matchString.toLowerCase(Locale.US);
			if (attributeName.equals(JSP11Namespace.ATTR_NAME_URI)) {
				ITaglibRecord[] availableTaglibRecords = TaglibIndex.getAvailableTaglibRecords(basePath);
				/*
				 * a simple enough way to remove duplicates (resolution at
				 * runtime would be nondeterministic anyway)
				 */
				Map uriToRecords = new HashMap();
				for (int taglibRecordNumber = 0; taglibRecordNumber < availableTaglibRecords.length; taglibRecordNumber++) {
					ITaglibRecord taglibRecord = availableTaglibRecords[taglibRecordNumber];
					ITaglibDescriptor descriptor = taglibRecord.getDescriptor();
					String uri = null;
					switch (taglibRecord.getRecordType()) {
						case ITaglibRecord.URL :
							uri = descriptor.getURI();
							uriToRecords.put(uri, taglibRecord);
							break;
						case ITaglibRecord.JAR : {
							IPath location = ((IJarRecord) taglibRecord).getLocation();
							IFile[] files = ResourcesPlugin.getWorkspace().getRoot().findFilesForLocation(location);
							IPath localContextRoot = TaglibIndex.getContextRoot(basePath);
							for (int fileNumber = 0; fileNumber < files.length; fileNumber++) {
								if (localContextRoot.isPrefixOf(files[fileNumber].getFullPath())) {
									uri = IPath.SEPARATOR + files[fileNumber].getFullPath().removeFirstSegments(localContextRoot.segmentCount()).toString();
									uriToRecords.put(uri, taglibRecord);
								}
							}
							break;
						}
						case ITaglibRecord.TLD : {
							IPath path = ((ITLDRecord) taglibRecord).getPath();
							IPath localContextRoot = TaglibIndex.getContextRoot(basePath);
							if (localContextRoot.isPrefixOf(path)) {
								uri = IPath.SEPARATOR + path.removeFirstSegments(localContextRoot.segmentCount()).toString();
								uriToRecords.put(uri, taglibRecord);
							}
							break;
						}
						case ITaglibRecord.TAGDIR :
							break;
					}
				}
				/*
				 * use the records and their descriptors to construct
				 * proposals
				 */
				Object[] uris = uriToRecords.keySet().toArray();
				for (int uriNumber = 0; uriNumber < uris.length; uriNumber++) {
					String uri = uris[uriNumber].toString();
					ITaglibRecord taglibRecord = (ITaglibRecord) uriToRecords.get(uri);
					ITaglibDescriptor descriptor = (taglibRecord).getDescriptor();
					if (uri != null && uri.length() > 0 && (matchString.length() == 0 || uri.toLowerCase(Locale.US).startsWith(lowerCaseMatch))) {
						String url = getSmallImageURL(taglibRecord);
						ImageDescriptor imageDescriptor = JSPUIPlugin.getInstance().getImageRegistry().getDescriptor(url);
						if (imageDescriptor == null && url != null) {
							URL imageURL;
							try {
								imageURL = new URL(url);
								imageDescriptor = ImageDescriptor.createFromURL(imageURL);
								JSPUIPlugin.getInstance().getImageRegistry().put(url, imageDescriptor);
							}
							catch (MalformedURLException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						}
						String additionalInfo = descriptor.getDescription() + "<br/>" + descriptor.getTlibVersion();
						CustomCompletionProposal proposal = new CustomCompletionProposal("\"" + uri + "\"", start, length, uri.length() + 2, JSPUIPlugin.getInstance().getImageRegistry().get(url), uri, null, additionalInfo, IRelevanceConstants.R_NONE);
						contentAssistRequest.addProposal(proposal);
					}
				}
			}
			else if (attributeName.equals(JSP11Namespace.ATTR_NAME_PREFIX)) {
				Node uriAttr = node.getAttributes().getNamedItem(JSP11Namespace.ATTR_NAME_URI);
				String uri = uriAttr.getNodeValue();
				ITaglibRecord[] availableTaglibRecords = TaglibIndex.getAvailableTaglibRecords(basePath);
				Map prefixMap = new HashMap();
				for (int taglibrecordNumber = 0; taglibrecordNumber < availableTaglibRecords.length; taglibrecordNumber++) {
					ITaglibDescriptor descriptor = availableTaglibRecords[taglibrecordNumber].getDescriptor();
					if (descriptor != null && descriptor.getURI().toLowerCase(Locale.US).equals(uri.toLowerCase(Locale.US))) {
						String shortName = descriptor.getShortName().trim();
						if (shortName.length() > 0) {
							boolean valid = true;
							for (int character = 0; character < shortName.length(); character++) {
								valid = valid && !Character.isWhitespace(shortName.charAt(character));
							}
							if (valid) {
								prefixMap.put(shortName, descriptor);
							}
						}
					}
				}
				Object prefixes[] = prefixMap.keySet().toArray();
				for (int j = 0; j < prefixes.length; j++) {
					String prefix = (String) prefixes[j];
					ITaglibDescriptor descriptor = (ITaglibDescriptor) prefixMap.get(prefix);
					CustomCompletionProposal proposal = new CustomCompletionProposal(prefix, start, length, prefix.length(), null, prefix, null, descriptor.getDescription(), IRelevanceConstants.R_NONE);
					contentAssistRequest.addProposal(proposal);
				}
			}
		}
	}

	/**
	 * Returns project request is in
	 * 
	 * @param request
	 * @return
	 */
	private IPath getBasePath(ContentAssistRequest request) {
		IPath baselocation = null;

		if (request != null) {
			IStructuredDocumentRegion region = request.getDocumentRegion();
			if (region != null) {
				IDocument document = region.getParentDocument();
				IStructuredModel model = null;
				try {
					model = StructuredModelManager.getModelManager().getExistingModelForRead(document);
					if (model != null) {
						String location = model.getBaseLocation();
						if (location != null) {
							baselocation = new Path(location);
						}
					}
				}
				finally {
					if (model != null)
						model.releaseFromRead();
				}
			}
		}
		return baselocation;
	}

}