/*
 * 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 nl.armatiek.xslweb.saxon.functions.common;

import java.util.ArrayList;

import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.Sequence;
import net.sf.saxon.om.ZeroOrMore;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.StringValue;
import nl.armatiek.xslweb.configuration.Attribute;
import nl.armatiek.xslweb.saxon.functions.ExtensionFunctionCall;

public abstract class GetCacheValueCall extends ExtensionFunctionCall {

  protected abstract ArrayList<Attribute> getAttributes(String cacheName, String keyName, XPathContext context);

  @Override
  public ZeroOrMore<Item> call(XPathContext context, Sequence[] arguments) throws XPathException {            
    try {
      String cacheName = ((StringValue) arguments[0].head()).getStringValue();
      String keyName = ((StringValue) arguments[1].head()).getStringValue();            
      ArrayList<Attribute> attrs = getAttributes(cacheName, keyName, context);      
      return attributeCollectionToSequence(attrs, context);            
    } catch (Exception e) {
      throw new XPathException("Could not get cache value", e);
    }
  }
}