/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.xerces.impl.xs.traversers;

import org.apache.xerces.impl.xs.SchemaGrammar;
import org.apache.xerces.impl.xs.SchemaSymbols;
import org.apache.xerces.impl.xs.XSElementDecl;
import org.apache.xerces.impl.xs.identity.IdentityConstraint;
import org.apache.xerces.impl.xs.identity.KeyRef;
import org.apache.xerces.impl.xs.identity.UniqueOrKey;
import org.apache.xerces.xni.QName;
import org.w3c.dom.Element;

/**
 * This class contains code that is used to traverse <keyref>s.
 *
 * @xerces.internal 
 *
 * @author Neil Graham, IBM
 * @version $Id: XSDKeyrefTraverser.java 446725 2006-09-15 20:40:10Z mrglavas $
 */
class XSDKeyrefTraverser extends XSDAbstractIDConstraintTraverser {

    public XSDKeyrefTraverser (XSDHandler handler,
                                  XSAttributeChecker gAttrCheck) {
        super(handler, gAttrCheck);
    }

    void traverse(Element krElem, XSElementDecl element,
            XSDocumentInfo schemaDoc, SchemaGrammar grammar) {

        // General Attribute Checking
        Object[] attrValues = fAttrChecker.checkAttributes(krElem, false, schemaDoc);

        // create identity constraint
        String krName = (String)attrValues[XSAttributeChecker.ATTIDX_NAME];
        if(krName == null){
            reportSchemaError("s4s-att-must-appear", new Object [] {SchemaSymbols.ELT_KEYREF , SchemaSymbols.ATT_NAME }, krElem);
            //return this array back to pool
            fAttrChecker.returnAttrArray(attrValues, schemaDoc);
            return;
        }
        QName kName = (QName)attrValues[XSAttributeChecker.ATTIDX_REFER];
        if(kName == null){
            reportSchemaError("s4s-att-must-appear", new Object [] {SchemaSymbols.ELT_KEYREF , SchemaSymbols.ATT_REFER }, krElem);
            //return this array back to pool
            fAttrChecker.returnAttrArray(attrValues, schemaDoc);
            return;
        }

        UniqueOrKey key = null;
        IdentityConstraint ret = (IdentityConstraint)fSchemaHandler.getGlobalDecl(schemaDoc, XSDHandler.IDENTITYCONSTRAINT_TYPE, kName, krElem);
        // if ret == null, we've already reported an error in getGlobalDecl
        // we report an error only when ret != null, and the return type keyref
        if (ret != null) {
            if (ret.getCategory() == IdentityConstraint.IC_KEY ||
                ret.getCategory() == IdentityConstraint.IC_UNIQUE) {
                key = (UniqueOrKey)ret;
            } else {
                reportSchemaError("src-resolve", new Object[]{kName.rawname, "identity constraint key/unique"}, krElem);
            }
        }

        if(key == null) {
            fAttrChecker.returnAttrArray(attrValues, schemaDoc);
            return;
        }

        KeyRef keyRef = new KeyRef(schemaDoc.fTargetNamespace, krName, element.fName, key);

        // add to element decl
        traverseIdentityConstraint(keyRef, krElem, schemaDoc, attrValues);

        //Schema Component Constraint: Identity-constraint Definition Properties Correct
        //2 If the {identity-constraint category} is keyref, the cardinality of the {fields} must equal that of the {fields} of the {referenced key}.
        if(key.getFieldCount() != keyRef.getFieldCount()) {
            reportSchemaError("c-props-correct.2" , new Object [] {krName,key.getIdentityConstraintName()}, krElem);
        } else {
            // add key reference to element decl
            // and stuff this in the grammar
            grammar.addIDConstraintDecl(element, keyRef);
        }

        // and put back attributes
        fAttrChecker.returnAttrArray(attrValues, schemaDoc);
    } // traverse(Element,int,XSDocumentInfo, SchemaGrammar)
} // XSDKeyrefTraverser