/*******************************************************************************
 * Copyright (c) 2004 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.core.internal.text;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IDocumentPartitioner;
import org.eclipse.jst.jsp.core.internal.encoding.JSPDocumentHeadContentDetector;
import org.eclipse.jst.jsp.core.internal.parser.JSPSourceParser;
import org.eclipse.jst.jsp.core.internal.provisional.JSP11Namespace;
import org.eclipse.jst.jsp.core.internal.provisional.JSP12Namespace;
import org.eclipse.jst.jsp.core.internal.regions.DOMJSPRegionContexts;
import org.eclipse.jst.jsp.core.text.IJSPPartitions;
import org.eclipse.wst.html.core.internal.text.StructuredTextPartitionerForHTML;
import org.eclipse.wst.sse.core.internal.ltk.parser.RegionParser;
import org.eclipse.wst.sse.core.internal.ltk.parser.TagMarker;
import org.eclipse.wst.sse.core.internal.parser.ForeignRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredTextPartitioner;
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.internal.text.rules.StructuredTextPartitioner;
import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;
import org.eclipse.wst.xml.core.internal.text.rules.StructuredTextPartitionerForXML;

public class StructuredTextPartitionerForJSP extends StructuredTextPartitioner {
	// for compatibility with v5.1.0, we'll reuse ST_JSP_DIRECTIVE for action
	// tags
	private final static boolean fEnableJSPActionPartitions = true;
	// list of valid JSP 1.2 tag and action names
	private static List fJSPActionTagNames = null;
	private static final String HTML_MIME_TYPE = "text/html"; //$NON-NLS-1$
	private static final String XHTML_MIME_TYPE = "text/xhtml"; //$NON-NLS-1$
	private static final String XML_MIME_TYPE = "text/xml"; //$NON-NLS-1$

	private final static String[] fConfiguredContentTypes = new String[]{IJSPPartitions.JSP_DEFAULT, IJSPPartitions.JSP_DEFAULT_EL, IJSPPartitions.JSP_DEFAULT_EL2, IJSPPartitions.JSP_DIRECTIVE, IJSPPartitions.JSP_CONTENT_DELIMITER, IJSPPartitions.JSP_CONTENT_JAVA, IJSPPartitions.JSP_CONTENT_JAVASCRIPT, IJSPPartitions.JSP_COMMENT};

	/**
	 * @return
	 */
	public static String[] getConfiguredContentTypes() {
		return fConfiguredContentTypes;
	}

	private IStructuredTextPartitioner fEmbeddedPartitioner = null;
	/*
	 * Save last taglib prefix that was checked (see isAction()) for better
	 * performance
	 */
	private String fLastCheckedPrefix = null;

	/**
	 * Assume language=java by default ... client, such as
	 * PageDirectiveAdapter, must set language of document partitioner,
	 * if/when it changes.
	 */
	private String fLanguage = "java"; //$NON-NLS-1$

	/**
	 * Constructor for JSPDocumentPartioner.
	 */
	public StructuredTextPartitionerForJSP() {
		super();
		if (fJSPActionTagNames == null) {
			fJSPActionTagNames = new ArrayList(); // uses .equals() for
			// contains()
			fJSPActionTagNames.add(JSP12Namespace.ElementName.DECLARATION);
			// fJSPActionTagNames.add(JSP12Namespace.ElementName.DIRECTIVE_INCLUDE);
			// fJSPActionTagNames.add(JSP12Namespace.ElementName.DIRECTIVE_PAGE);
			// fJSPActionTagNames.add(JSP12Namespace.ElementName.DIRECTIVE_TAGLIB);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.EXPRESSION);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.FALLBACK);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.FORWARD);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.GETPROPERTY);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.INCLUDE);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.PARAM);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.PARAMS);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.PLUGIN);
			// fJSPActionTagNames.add(JSP12Namespace.ElementName.ROOT);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.SCRIPTLET);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.SETPROPERTY);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.TEXT);
			fJSPActionTagNames.add(JSP12Namespace.ElementName.USEBEAN);
		}
	}

	/**
	 * @see org.eclipse.jface.text.IDocumentPartitioner#connect(org.eclipse.jface.text.IDocument)
	 */
	public void connect(IDocument document) {
		super.connect(document);
		fSupportedTypes = null;
	}

	private IStructuredTextPartitioner createStructuredTextPartitioner(IStructuredDocument structuredDocument) {
		IStructuredTextPartitioner result = null;
		JSPDocumentHeadContentDetector jspHeadContentDetector = new JSPDocumentHeadContentDetector();
		jspHeadContentDetector.set(structuredDocument);
		String contentType;
		try {
			contentType = jspHeadContentDetector.getContentType();
		}
		catch (IOException e) {
			// should be impossible in this context
			throw new Error(e);
		}
		if (contentType == null) {
			contentType = "text/html"; //$NON-NLS-1$
		}
		// we currently only have two ... eventually should
		// make or tie-in to existing registry.
		if (contentType.equalsIgnoreCase(HTML_MIME_TYPE)) {
			result = new StructuredTextPartitionerForHTML();
			result.connect(structuredDocument);
		}
		else if (contentType.equalsIgnoreCase(XHTML_MIME_TYPE)) {
			result = new StructuredTextPartitionerForHTML();
			result.connect(structuredDocument);
		}
		else if (contentType.equalsIgnoreCase(XML_MIME_TYPE) || contentType.endsWith("+xml")) { //$NON-NLS-1$
			result = new StructuredTextPartitionerForXML();
			result.connect(structuredDocument);
		}
		else {
			result = new StructuredTextPartitioner();
			result.connect(structuredDocument);
		}
		return result;

	}

	/**
	 * @see org.eclipse.jface.text.IDocumentPartitioner#disconnect()
	 */
	public void disconnect() {
		if (fEmbeddedPartitioner != null) {
			fEmbeddedPartitioner.disconnect();
			// https://w3.opensource.ibm.com/bugzilla/show_bug.cgi?id=4909
			/**
			 * force recreation when reconnected
			 */
			fEmbeddedPartitioner = null;
		}
		// super.disconnect should come at end, since it (may) set
		// structuredDocument to null
		super.disconnect();
	}

	public String getDefaultPartitionType() {
		return getEmbeddedPartitioner().getDefaultPartitionType();
	}

	/**
	 * Returns the embeddedPartitioner.
	 * 
	 * @return IStructuredTextPartitioner
	 */
	public IStructuredTextPartitioner getEmbeddedPartitioner() {
		if (fEmbeddedPartitioner == null) {
			fEmbeddedPartitioner = createStructuredTextPartitioner(fStructuredDocument);
			fEmbeddedPartitioner.connect(fStructuredDocument);
		}

		return fEmbeddedPartitioner;
	}

	/**
	 * Returns the language.
	 * 
	 * @return String
	 */
	public String getLanguage() {
		return fLanguage;
	}

	private List getLocalLegalContentTypes() {
		List types = new ArrayList();
		Object[] configuredTypes = getConfiguredContentTypes();
		for (int i = 0; i < configuredTypes.length; i++)
			types.add(configuredTypes[i]);
		return types;
	}

	private String getParentName(IStructuredDocumentRegion sdRegion) {
		String result = "UNKNOWN"; //$NON-NLS-1$
		while (sdRegion != null && isValidJspActionRegionType(sdRegion.getType()))
			sdRegion = sdRegion.getPrevious();

		if (sdRegion != null) {
			ITextRegionList regions = sdRegion.getRegions();
			// only find parent names from a start tag
			if (regions.size() > 1) {
				ITextRegion r = regions.get(1);
				if (regions.get(0).getType().equals(DOMRegionContext.XML_TAG_OPEN) && r.getType().equals(DOMRegionContext.XML_TAG_NAME)) {
					result = sdRegion.getText(r);
				}
			}
		}
		return result;
	}

	protected String getPartitionType(ForeignRegion region, int offset) {
		return getEmbeddedPartitioner().getPartitionType(region, offset);
	}


	public String getPartitionType(ITextRegion region, int offset) {
		String result = null;
		final String region_type = region.getType();
		if (region_type == DOMJSPRegionContexts.JSP_CONTENT) {
			result = getPartitionTypeForDocumentLanguage();
		}
		else if (region_type == DOMJSPRegionContexts.JSP_COMMENT_TEXT || region_type == DOMJSPRegionContexts.JSP_COMMENT_OPEN || region_type == DOMJSPRegionContexts.JSP_COMMENT_CLOSE)
			result = IJSPPartitions.JSP_COMMENT;
		else if (region_type == DOMJSPRegionContexts.JSP_DIRECTIVE_NAME || region_type == DOMJSPRegionContexts.JSP_DIRECTIVE_OPEN || region_type == DOMJSPRegionContexts.JSP_DIRECTIVE_CLOSE)
			result = IJSPPartitions.JSP_DIRECTIVE;
		else if (region_type == DOMJSPRegionContexts.JSP_CLOSE || region_type == DOMJSPRegionContexts.JSP_SCRIPTLET_OPEN || region_type == DOMJSPRegionContexts.JSP_EXPRESSION_OPEN || region_type == DOMJSPRegionContexts.JSP_DECLARATION_OPEN)
			result = IJSPPartitions.JSP_CONTENT_DELIMITER;
		else if (region_type == DOMJSPRegionContexts.JSP_ROOT_TAG_NAME)
			result = IJSPPartitions.JSP_DEFAULT;
		else if (region_type == DOMJSPRegionContexts.JSP_EL_OPEN || region_type == DOMJSPRegionContexts.JSP_EL_CONTENT || region_type == DOMJSPRegionContexts.JSP_EL_CLOSE || region_type == DOMJSPRegionContexts.JSP_EL_DQUOTE || region_type == DOMJSPRegionContexts.JSP_EL_SQUOTE || region_type == DOMJSPRegionContexts.JSP_EL_QUOTED_CONTENT)
			result = IJSPPartitions.JSP_DEFAULT_EL;
		else if (region_type == DOMJSPRegionContexts.JSP_VBL_OPEN || region_type == DOMJSPRegionContexts.JSP_VBL_CONTENT || region_type == DOMJSPRegionContexts.JSP_VBL_CLOSE || region_type == DOMJSPRegionContexts.JSP_VBL_DQUOTE || region_type == DOMJSPRegionContexts.JSP_VBL_SQUOTE || region_type == DOMJSPRegionContexts.JSP_VBL_QUOTED_CONTENT)
			result = IJSPPartitions.JSP_DEFAULT_EL2;
		else if (region_type == DOMRegionContext.XML_CONTENT) {
			// possibly between <jsp:scriptlet>, <jsp:expression>,
			// <jsp:declaration>
			IStructuredDocumentRegion sdRegion = this.fStructuredDocument.getRegionAtCharacterOffset(offset);
			if (isJspJavaActionName(getParentName(sdRegion)))
				result = getPartitionTypeForDocumentLanguage();
			else
				result = getDefaultPartitionType();
		}
		else {
			result = getEmbeddedPartitioner().getPartitionType(region, offset);
		}
		return result;
	}

	public String getPartitionTypeBetween(IStructuredDocumentRegion previousNode, IStructuredDocumentRegion nextNode) {
		return getEmbeddedPartitioner().getPartitionTypeBetween(previousNode, nextNode);
	}

	private String getPartitionTypeForDocumentLanguage() {
		String result;
		if (fLanguage == null || fLanguage.equalsIgnoreCase("java")) { //$NON-NLS-1$
			result = IJSPPartitions.JSP_CONTENT_JAVA;
		}
		else if (fLanguage.equalsIgnoreCase("javascript")) { //$NON-NLS-1$
			result = IJSPPartitions.JSP_CONTENT_JAVASCRIPT;
		}
		else {
			result = IJSPPartitions.JSP_SCRIPT_PREFIX + getLanguage().toUpperCase(Locale.ENGLISH);
		}
		return result;
	}

	protected void initLegalContentTypes() {
		List combinedTypes = getLocalLegalContentTypes();
		if (getEmbeddedPartitioner() != null) {
			String[] moreTypes = getEmbeddedPartitioner().getLegalContentTypes();
			for (int i = 0; i < moreTypes.length; i++)
				combinedTypes.add(moreTypes[i]);
		}
		fSupportedTypes = new String[0];
		combinedTypes.toArray(fSupportedTypes);
	}

	/**
	 * @param sdRegion
	 * @param offset
	 * @return
	 */
	private boolean isAction(IStructuredDocumentRegion sdRegion, int offset) {
		if (!sdRegion.getType().equals(DOMRegionContext.XML_TAG_NAME))
			return false;
		/*
		 * shouldn't get a tag name region type unless a tag name region
		 * exists at [1]
		 */
		ITextRegion tagNameRegion = sdRegion.getRegions().get(1);
		String tagName = sdRegion.getText(tagNameRegion);

		RegionParser parser = fStructuredDocument.getParser();
		if (parser instanceof JSPSourceParser) {
			if (tagName.equals(fLastCheckedPrefix))
				return true;
			List fCustomActionPrefixes = ((JSPSourceParser) parser).getNestablePrefixes();
			for (int i = 0; i < fCustomActionPrefixes.size(); i++)
				if (tagName.startsWith(((TagMarker) fCustomActionPrefixes.get(i)).getTagName())) {
					fLastCheckedPrefix = tagName;
					return true;
				}
		}
		return false;
	}

	protected boolean isDocumentRegionBasedPartition(IStructuredDocumentRegion sdRegion, ITextRegion containedChildRegion, int offset) {
		String documentRegionContext = sdRegion.getType();
		if (containedChildRegion != null) {
			if (documentRegionContext.equals(DOMJSPRegionContexts.JSP_DIRECTIVE_NAME) || documentRegionContext.equals(DOMJSPRegionContexts.JSP_ROOT_TAG_NAME)) {
				setInternalPartition(offset, containedChildRegion.getLength(), IJSPPartitions.JSP_DIRECTIVE);
				return true;
			}
			// https://bugs.eclipse.org/bugs/show_bug.cgi?id=113346
			if (fEnableJSPActionPartitions && isAction(sdRegion, offset) && !(containedChildRegion instanceof ITextRegionContainer)) {
				// if (fEnableJSPActionPartitions && isAction(sdRegion,
				// offset)) {
				setInternalPartition(offset, containedChildRegion.getLength(), IJSPPartitions.JSP_DIRECTIVE);
				return true;
			}
		}
		return super.isDocumentRegionBasedPartition(sdRegion, containedChildRegion, offset);
	}

	/**
	 * @param possibleJspJavaAction
	 * @return
	 */
	private boolean isJspJavaActionName(String possibleJspJavaAction) {
		return possibleJspJavaAction.equals(JSP11Namespace.ElementName.SCRIPTLET) || possibleJspJavaAction.equals(JSP11Namespace.ElementName.EXPRESSION) || possibleJspJavaAction.equals(JSP11Namespace.ElementName.DECLARATION);
	}

	private boolean isValidJspActionRegionType(String type) {
		// true for anything that can be within <jsp:scriptlet>,
		// <jsp:expression>, <jsp:declaration>
		return type == DOMRegionContext.XML_CONTENT || type == DOMRegionContext.BLOCK_TEXT || type == DOMRegionContext.XML_CDATA_OPEN || type == DOMRegionContext.XML_CDATA_TEXT || type == DOMRegionContext.XML_CDATA_CLOSE;
	}

	public IDocumentPartitioner newInstance() {
		StructuredTextPartitionerForJSP instance = new StructuredTextPartitionerForJSP();
		instance.setEmbeddedPartitioner(createStructuredTextPartitioner(fStructuredDocument));
		instance.setLanguage(fLanguage);
		return instance;
	}

	/**
	 * Sets the embeddedPartitioner.
	 * 
	 * @param embeddedPartitioner
	 *            The embeddedPartitioner to set
	 */
	public void setEmbeddedPartitioner(IStructuredTextPartitioner embeddedPartitioner) {
		// https://w3.opensource.ibm.com/bugzilla/show_bug.cgi?id=4909
		/**
		 * manage connected state of embedded partitioner
		 */
		if (fEmbeddedPartitioner != null && fStructuredDocument != null) {
			fEmbeddedPartitioner.disconnect();
		}

		this.fEmbeddedPartitioner = embeddedPartitioner;

		if (fEmbeddedPartitioner != null && fStructuredDocument != null) {
			fEmbeddedPartitioner.connect(fStructuredDocument);
		}
	}

	protected void setInternalPartition(int offset, int length, String type) {
		// TODO: need to carry this single instance idea further to be
		// complete,
		// but hopefully this will be less garbage than before (especially for
		// HTML, XML,
		// naturally!)
		internalReusedTempInstance = getEmbeddedPartitioner().createPartition(offset, length, type);

	}

	/**
	 * Sets the language.
	 * 
	 * @param language
	 *            The language to set
	 */
	public void setLanguage(String language) {
		this.fLanguage = language;
	}

}