/*******************************************************************************
 * Copyright (c) 2010 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 org.eclipse.core.resources.IResource;
import org.eclipse.jst.jsp.core.internal.provisional.JSP11Namespace;
import org.eclipse.jst.jsp.ui.internal.editor.JSPEditorPluginImageHelper;
import org.eclipse.jst.jsp.ui.internal.editor.JSPEditorPluginImages;
import org.eclipse.wst.sse.core.internal.provisional.IndexedRegion;
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.contentassist.CompletionProposalInvocationContext;
import org.eclipse.wst.sse.ui.internal.contentassist.CustomCompletionProposal;
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.eclipse.wst.xml.ui.internal.contentassist.DefaultXMLCompletionProposalComputer;
import org.eclipse.wst.xml.ui.internal.contentassist.XMLRelevanceConstants;
import org.eclipse.wst.xml.ui.internal.util.SharedXMLEditorPluginImageHelper;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * <p>This class computes attribute value completion proposals
 * for <code>&lt;jsp:[gs]etProperty&gt;</code> tags.</p>
 */
public class JSPPropertyCompletionProposalComputer extends
		DefaultXMLCompletionProposalComputer {

	/**
	 * @see org.eclipse.wst.xml.ui.internal.contentassist.DefaultXMLCompletionProposalComputer#addAttributeValueProposals(org.eclipse.wst.xml.ui.internal.contentassist.ContentAssistRequest, org.eclipse.wst.sse.ui.contentassist.CompletionProposalInvocationContext)
	 */
	protected void addAttributeValueProposals(
			ContentAssistRequest contentAssistRequest,
			CompletionProposalInvocationContext context) {
		
		IDOMNode node = (IDOMNode) contentAssistRequest.getNode();

		//only add attribute value proposals for specific elements
		if(node.getNodeName().equals(JSP11Namespace.ElementName.SETPROPERTY) ||
				node.getNodeName().equals(JSP11Namespace.ElementName.GETPROPERTY)) {
		
			// 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;
	
			// get the attribute in question (first attr name to the left of the cursor)
			ITextRegion attrNameRegion = null;
			String attributeName = null;
			while (i >= 0) {
				attrNameRegion = openRegions.get(i--);
				if (attrNameRegion.getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_NAME)
					break;
			}
			if (attrNameRegion != null)
				attributeName = open.getText(attrNameRegion);
	
			// determine get or set
			ITextRegion tagNameRegion = null;
			boolean isGetProperty = true;
			for (int j = 0; j < openRegions.size(); j++) {
				tagNameRegion = openRegions.get(j);
				if (tagNameRegion.getType() == DOMRegionContext.XML_TAG_NAME &&
						open.getText(tagNameRegion).trim().equals("jsp:setProperty")) { //$NON-NLS-1$
					isGetProperty = false;
					break;
				}
			}
	
			String currentValue = null;
			if (contentAssistRequest.getRegion().getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_VALUE)
				currentValue = contentAssistRequest.getText();
			else
				currentValue = ""; //$NON-NLS-1$
			String matchString = null;
			// fixups since the matchString computations don't care if there are quotes around the value
			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());
			}
			// for now we ignore complicated values such as jsp embedded in an attribute
			boolean existingComplicatedValue =
				contentAssistRequest.getRegion() != null &&
				contentAssistRequest.getRegion() instanceof ITextRegionContainer;
			if (existingComplicatedValue) {
				contentAssistRequest.getProposals().clear();
				contentAssistRequest.getMacros().clear();
			}
			else {
				if (attributeName.equals(JSP11Namespace.ATTR_NAME_NAME)) {
					addBeanNameProposals(contentAssistRequest, node, matchString);
				}
				else if (attributeName.equals(JSP11Namespace.ATTR_NAME_PROPERTY)) {
					addBeanPropertyProposals(contentAssistRequest, node, isGetProperty, matchString);
				}
			}
		}
	}
	
	/**
	 * <p>Add bean property proposals to the given {@link ContentAssistRequest}</p>
	 * 
	 * @param contentAssistRequest
	 * @param node
	 * @param isGetProperty
	 * @param matchString
	 */
	private void addBeanPropertyProposals(ContentAssistRequest contentAssistRequest,
			IDOMNode node, boolean isGetProperty, String matchString) {
		
		if (((Element) node).hasAttribute(JSP11Namespace.ATTR_NAME_NAME)) {
			// assumes that the node is the [gs]etProperty tag
			String useBeanName = ((Element) node).getAttribute(JSP11Namespace.ATTR_NAME_NAME);
			// properties can only be provided if a class/type/beanName has been declared
			if (useBeanName.length() > 0) {
				NodeList useBeans = node.getOwnerDocument().getElementsByTagName(JSP11Namespace.ElementName.USEBEAN);
				if (useBeans != null) {
					String typeName = null;
					for (int j = 0; j < useBeans.getLength(); j++) {
						if (useBeans.item(j).getNodeType() != Node.ELEMENT_NODE)
							continue;
						Element useBean = (Element) useBeans.item(j);
						if (useBean instanceof IndexedRegion && ((IndexedRegion) useBean).getStartOffset() < node.getStartOffset()) {
							if (useBeanName.equals(useBean.getAttribute(JSP11Namespace.ATTR_NAME_ID))) {
								typeName = useBean.getAttribute(JSP11Namespace.ATTR_NAME_CLASS);
								if (!useBean.hasAttribute(JSP11Namespace.ATTR_NAME_CLASS) || typeName.length() < 1) {
									typeName = useBean.getAttribute(JSP11Namespace.ATTR_NAME_TYPE);
								}
								if (!useBean.hasAttribute(JSP11Namespace.ATTR_NAME_TYPE) || typeName.length() < 1) {
									typeName = useBean.getAttribute(JSP11Namespace.ATTR_NAME_BEAN_NAME);
								}
							}
						}
					}
					if (typeName != null && typeName.length() > 0) {
						// find the class/type/beanName definition and obtain the list of properties
						IBeanInfoProvider provider = new BeanInfoProvider();
						IResource resource = JSPContentAssistHelper.getResource(contentAssistRequest);
						IJavaPropertyDescriptor[] descriptors = provider.getRuntimeProperties(resource, typeName);
						CustomCompletionProposal proposal = null;
						String displayString = ""; //$NON-NLS-1$
						for (int j = 0; j < descriptors.length; j++) {
							IJavaPropertyDescriptor pd = descriptors[j];
							// check whether it's get or set kinda property
							if (pd.getReadable() && isGetProperty || pd.getWriteable() && !isGetProperty) {
								// filter attr value name
								if (matchString.length() == 0 || pd.getName().toLowerCase().startsWith(matchString.toLowerCase())) {
									displayString = pd.getDisplayName();
									if (pd.getDeclaredType() != null && pd.getDeclaredType().length() > 0)
										displayString += " - " + pd.getDeclaredType(); //$NON-NLS-1$
									proposal = new CustomCompletionProposal("\"" + pd.getName() + "\"", //$NON-NLS-1$ //$NON-NLS-2$
												contentAssistRequest.getReplacementBeginPosition(),
												contentAssistRequest.getReplacementLength(),
												pd.getName().length() + 2,
												SharedXMLEditorPluginImageHelper.getImage(SharedXMLEditorPluginImageHelper.IMG_OBJ_ATTRIBUTE),
												displayString, null, pd.getDeclaredType(), XMLRelevanceConstants.R_XML_ATTRIBUTE_VALUE);
									contentAssistRequest.addProposal(proposal);
								}
							}
						}
					}
				}
			}
		}
	}

	/**
	 * <p>Add bean name propoasals to the given {@link ContentAssistRequest}</p>
	 * 
	 * @param contentAssistRequest
	 * @param node
	 * @param matchString
	 */
	private void addBeanNameProposals(ContentAssistRequest contentAssistRequest, IDOMNode node, String matchString) {
		// will not catch useBeans specified using other than actual DOM Nodes
		NodeList useBeans = node.getOwnerDocument().getElementsByTagName(JSP11Namespace.ElementName.USEBEAN);
		if (useBeans != null) {
			String id = ""; //$NON-NLS-1$
			String displayString = null;
			String classOrType = null;
			String imageName = JSPEditorPluginImages.IMG_OBJ_CLASS_OBJ;
			for (int j = 0; j < useBeans.getLength(); j++) {
				if (useBeans.item(j).getNodeType() != Node.ELEMENT_NODE) {
					continue;
				}
				Element useBean = (Element) useBeans.item(j);
				if (useBean instanceof IndexedRegion &&
						((IndexedRegion) useBean).getStartOffset() < node.getStartOffset() &&
						useBean.hasAttribute(JSP11Namespace.ATTR_NAME_ID)) {
					
					id = useBean.hasAttribute(JSP11Namespace.ATTR_NAME_ID) ?
							StringUtils.strip(useBean.getAttribute(JSP11Namespace.ATTR_NAME_ID)) : null;
					displayString = null;
					classOrType = null;
					imageName = JSPEditorPluginImages.IMG_OBJ_CLASS_OBJ;
					// set the Image based on whether the class, type, or beanName attribute is present
					if (useBean.hasAttribute(JSP11Namespace.ATTR_NAME_CLASS))
						classOrType = useBean.getAttribute(JSP11Namespace.ATTR_NAME_CLASS);
					if ((classOrType == null || classOrType.length() < 1) && useBean.hasAttribute(JSP11Namespace.ATTR_NAME_TYPE)) {
						classOrType = useBean.getAttribute(JSP11Namespace.ATTR_NAME_TYPE);
						imageName = JSPEditorPluginImages.IMG_OBJ_PUBLIC;
					}
					if ((classOrType == null || classOrType.length() < 1) && useBean.hasAttribute(JSP11Namespace.ATTR_NAME_BEAN_NAME)) {
						classOrType = useBean.getAttribute(JSP11Namespace.ATTR_NAME_BEAN_NAME);
						imageName = JSPEditorPluginImages.IMG_OBJ_PUBLIC;
					}
					if (classOrType != null && classOrType.length() > 0) {
						displayString = id + " - " + classOrType; //$NON-NLS-1$
					} else {
						displayString = id;
					}

					// https://w3.opensource.ibm.com/bugzilla/show_bug.cgi?id=2341
					if(id != null) {
					    // filter
						if (matchString.length() == 0 || id.startsWith(matchString)) {
							CustomCompletionProposal proposal = new CustomCompletionProposal("\"" + id + "\"", //$NON-NLS-1$ //$NON-NLS-2$
										contentAssistRequest.getReplacementBeginPosition(), 
                                        contentAssistRequest.getReplacementLength(), 
                                        id.length() + 2, 
                                        JSPEditorPluginImageHelper.getInstance().getImage(imageName), 
                                        displayString, null, null, 
                                        XMLRelevanceConstants.R_XML_ATTRIBUTE_VALUE);
							contentAssistRequest.addProposal(proposal);
						}
					}
				}
			}
		}
	}
}