/*
 *
 *          Copyright (c) 2013,2019  AT&T Knowledge Ventures
 *                     SPDX-License-Identifier: MIT
 */

package com.att.research.xacmlatt.pdp.policy.dom;

import java.util.ArrayList;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.att.research.xacml.api.XACML3;
import com.att.research.xacml.std.StdStatusCode;
import com.att.research.xacml.std.dom.DOMAttributeValue;
import com.att.research.xacml.std.dom.DOMProperties;
import com.att.research.xacml.std.dom.DOMStructureException;
import com.att.research.xacml.std.dom.DOMUtil;
import com.att.research.xacmlatt.pdp.policy.CombinerParameter;

/**
 * DOMCombinerParameter extends {@link com.att.research.xacmlatt.pdp.policy.CombinerParameter} with methods for
 * creation from DOM {@link org.w3c.dom.Node}s.
 * 
 * @author car
 * @version $Revision: 1.2 $
 */
public class DOMCombinerParameter extends CombinerParameter {
	private static final Logger logger	= LoggerFactory.getLogger(DOMCombinerParameter.class);
	
	protected DOMCombinerParameter() {
		
	}
	
	/**
	 * Creates a new <code>CombinerParameter</code> by parsing the given <code>Node</code> representing a XACML CombinerParameter element.
	 * 
	 * @param nodeCombinerParameter the <code>Node</code> representing the XACML CombinerParameter element
	 * @return a new <code>CombinerParameter</code> parsed from the given <code>Node</code>
	 * @throws DOMStructureException if there is an error parsing the <code>Node</code>
	 */
	public static CombinerParameter newInstance(Node nodeCombinerParameter) throws DOMStructureException {
		Element elementCombinerParameter		= DOMUtil.getElement(nodeCombinerParameter);
		boolean bLenient						= DOMProperties.isLenient();
		
		DOMCombinerParameter combinerParameter	= new DOMCombinerParameter();
		
		try {
			NodeList children					= elementCombinerParameter.getChildNodes();
			int numChildren;
			if (children != null && (numChildren = children.getLength()) > 0) {
				for (int i = 0 ; i < numChildren ; i++) {
					Node child	= children.item(i);
					if (DOMUtil.isElement(child)) {
						if (DOMUtil.isInNamespace(child, XACML3.XMLNS) && XACML3.ELEMENT_ATTRIBUTEVALUE.equals(child.getLocalName())) {
							if (combinerParameter.getAttributeValue() != null && !bLenient) {
								throw DOMUtil.newUnexpectedElementException(child, elementCombinerParameter);
							} else {
								combinerParameter.setAttributeValue(DOMAttributeValue.newInstance(child, null));
							}
						} else if (!bLenient) {
							throw DOMUtil.newUnexpectedElementException(child, elementCombinerParameter);
						}
					}
				}
			}
			
			if (combinerParameter.getAttributeValue() == null && !bLenient) {
				throw DOMUtil.newMissingElementException(elementCombinerParameter, XACML3.XMLNS, XACML3.ELEMENT_ATTRIBUTEVALUE);
			}			
			combinerParameter.setName(DOMUtil.getStringAttribute(elementCombinerParameter, XACML3.ATTRIBUTE_PARAMETERNAME, !bLenient));
		} catch (DOMStructureException ex) {
			combinerParameter.setStatus(StdStatusCode.STATUS_CODE_SYNTAX_ERROR, ex.getMessage());
			if (DOMProperties.throwsExceptions()) {
				throw ex;
			}
		}
		
		return combinerParameter;
	}
	
	public static boolean repair(Node nodeCombinerParameter) throws DOMStructureException {
		Element elementCombinerParameter	= DOMUtil.getElement(nodeCombinerParameter);
		boolean result						= false;
		
		NodeList children					= elementCombinerParameter.getChildNodes();
		int numChildren;
		boolean sawAttributeValue			= false;
		
		if (children != null && (numChildren = children.getLength()) > 0) {
			for (int i = 0 ; i < numChildren ; i++) {
				Node child	= children.item(i);
				if (DOMUtil.isElement(child)) {
					if (DOMUtil.isInNamespace(child, XACML3.XMLNS) && XACML3.ELEMENT_ATTRIBUTEVALUE.equals(child.getLocalName())) {
						if (sawAttributeValue) {
							logger.warn("Unexpected element {}", child.getNodeName());
							elementCombinerParameter.removeChild(child);
							result	= true;
						} else {
							result				= DOMAttributeValue.repair(child) || result;
							sawAttributeValue	= true;
						}
					} else {
						logger.warn("Unexpected element {}", child.getNodeName());
						elementCombinerParameter.removeChild(child);
						result	= true;
					}
				}
			}
		}
		
		if (!sawAttributeValue) {
			throw DOMUtil.newMissingElementException(elementCombinerParameter, XACML3.XMLNS, XACML3.ELEMENT_ATTRIBUTEVALUE);
		}
		
		result	= DOMUtil.repairStringAttribute(elementCombinerParameter, XACML3.ATTRIBUTE_PARAMETERNAME, "parameter", logger) || result;
		
		return result;
	}
	
	/**
	 * Creates a <code>List</code> of <code>CombinerParameter</code>s by parsing the given <code>Node</code> representing a
	 * XACML CombinerParameters element.
	 * 
	 * @param nodeCombinerParameters the <code>Node</code> representing the XACML CombinerParameters element
	 * @return a <code>List</code> of <code>CombinerParameter</code>s parsed from the given <code>Node</code>.
	 * @throws DOMStructureException if there is an error parsing the <code>Node</code>
	 */
	public static List<CombinerParameter> newList(Node nodeCombinerParameters) throws DOMStructureException {
		Element elementCombinerParameters	= DOMUtil.getElement(nodeCombinerParameters);
		boolean bLenient					= DOMProperties.isLenient();
		
		List<CombinerParameter> listCombinerParameters	= new ArrayList<>();
		
		NodeList children	= elementCombinerParameters.getChildNodes();
		int numChildren;
		if (children != null && (numChildren = children.getLength()) > 0) {
			for (int i = 0 ; i < numChildren ; i++) {
				Node child	= children.item(i);
				if (DOMUtil.isElement(child)) {
					if (DOMUtil.isInNamespace(child, XACML3.XMLNS) && XACML3.ELEMENT_COMBINERPARAMETER.equals(child.getLocalName())) {
						listCombinerParameters.add(DOMCombinerParameter.newInstance(child));
					} else if (!bLenient) {
						throw DOMUtil.newUnexpectedElementException(child, elementCombinerParameters);
					}
				}
			}
		}
		return listCombinerParameters;
	}
	
	public static boolean repairList(Node nodeCombinerParameters) throws DOMStructureException {
		Element elementCombinerParameters	= DOMUtil.getElement(nodeCombinerParameters);
		boolean result						= false;
		
		NodeList children	= elementCombinerParameters.getChildNodes();
		int numChildren;
		if (children != null && (numChildren = children.getLength()) > 0) {
			for (int i = 0 ; i < numChildren ; i++) {
				Node child	= children.item(i);
				if (DOMUtil.isElement(child)) {
					if (DOMUtil.isInNamespace(child, XACML3.XMLNS) && XACML3.ELEMENT_COMBINERPARAMETER.equals(child.getLocalName())) {
						result	= DOMCombinerParameter.repair(child) || result;
					} else {
						logger.warn("Unexpected element {}", child.getNodeName());
						elementCombinerParameters.removeChild(child);
						result	= true;
					}
				}
			}
		}
		return result;
	}
}
