/*******************************************************************************
 * Copyright (c) 2001, 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/
package org.eclipse.wst.xml.ui.internal.contentassist;


import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.xml.core.internal.contentmodel.CMAttributeDeclaration;
import org.eclipse.wst.xml.core.internal.contentmodel.CMDataType;
import org.eclipse.wst.xml.core.internal.contentmodel.CMElementDeclaration;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
import org.w3c.dom.Node;


public class XMLContentModelGenerator extends AbstractContentModelGenerator {

	/**
	 * ISSUE: this is a bit of hidden JSP knowledge that was implemented this
	 * way for expedency. Should be evolved in future to depend on
	 * "nestedContext".
	 */
	private class DOMJSPRegionContextsPrivateCopy {
		private static final String JSP_DIRECTIVE_OPEN = "JSP_DIRECTIVE_OPEN"; //$NON-NLS-1$
	}

	/**
	 * XMLContentModelGenerator constructor comment.
	 */
	public XMLContentModelGenerator() {
		super();
	}

	public void generateAttribute(CMAttributeDeclaration attrDecl, StringBuffer buffer) {
		if ((attrDecl == null) || (buffer == null)) {
			return;
		}
		int usage = attrDecl.getUsage();
		if (usage == CMAttributeDeclaration.REQUIRED) {
			buffer.append(" "); //$NON-NLS-1$
			generateRequiredAttribute(null, attrDecl, buffer); // todo pass
			// ownerNode as
			// 1st param
		}
		return;
	}

	protected void generateEndTag(String tagName, Node parentNode, CMElementDeclaration elementDecl, StringBuffer buffer) {
		if (elementDecl == null) {
			return;
		}
		if (elementDecl.getContentType() != CMElementDeclaration.EMPTY) {
			buffer.append("</" + tagName + ">");//$NON-NLS-2$//$NON-NLS-1$
		}
		return;
	}

	public void generateRequiredAttribute(Node ownerNode, CMAttributeDeclaration attrDecl, StringBuffer buffer) {
		if ((attrDecl == null) || (buffer == null)) {
			return;
		}

		// attribute name
		String attributeName = getRequiredName(ownerNode, attrDecl);
		CMDataType attrType = attrDecl.getAttrType();
		// = sign
		buffer.append(attributeName + "=\""); //$NON-NLS-1$
		// attribute value
		if (attrType != null) {
			// insert any value that is implied
			if ((attrType.getImpliedValueKind() != CMDataType.IMPLIED_VALUE_NONE) && (attrType.getImpliedValue() != null)) {
				buffer.append(attrType.getImpliedValue());
			}
			// otherwise, if an enumerated list of values exists, use the
			// first value
			else if ((attrType.getEnumeratedValues() != null) && (attrType.getEnumeratedValues().length > 0)) {
				buffer.append(attrType.getEnumeratedValues()[0]);
			}
		}
		buffer.append("\""); //$NON-NLS-1$
		return;
	}

	protected void generateStartTag(String tagName, Node parentNode, CMElementDeclaration elementDecl, StringBuffer buffer) {
		if ((elementDecl == null) || (buffer == null)) {
			return;
		}
		buffer.append("<" + tagName);//$NON-NLS-1$
		generateAttributes(elementDecl, buffer);
		buffer.append(getStartTagClose(parentNode, elementDecl));
		return;
	}

	public int getMinimalStartTagLength(Node node, CMElementDeclaration elementDecl) {
		if (elementDecl == null) {
			return 0;
		}
		if (requiresAttributes(elementDecl)) {
			return getRequiredName(node, elementDecl).length() + 2; // < +
			// name +
			// space
		}
		else {
			return 1 + getRequiredName(node, elementDecl).length() + getStartTagClose(node, elementDecl).length(); // < +
			// name
			// +
			// appropriate
			// close
		}
	}

	protected String getOtherClose(Node notATagNode) {
		if (notATagNode instanceof IDOMNode) {
			IStructuredDocumentRegion node = ((IDOMNode) notATagNode).getStartStructuredDocumentRegion();
			if ((node != null) && (node.getNumberOfRegions() > 1) && node.getRegions().get(0).getType().equals(DOMJSPRegionContextsPrivateCopy.JSP_DIRECTIVE_OPEN)) {
				return "%>"; //$NON-NLS-1$
			}
		}
		return null;
	}

	public String getStartTagClose(Node parentNode, CMElementDeclaration elementDecl) {
		String other = getOtherClose(parentNode);
		if (other != null) {
			return other;
		}
		if (elementDecl == null) {
			return ">";//$NON-NLS-1$
		}
		if (elementDecl.getContentType() == CMElementDeclaration.EMPTY) {
			return "/>"; //$NON-NLS-1$
		}
		return ">"; //$NON-NLS-1$
	}
}